Publications by authors named "Majid Esmaeilzadeh"

32 Publications

Intracranial emergencies during pregnancy requiring urgent neurosurgical treatment.

Clin Neurol Neurosurg 2020 08 12;195:105905. Epub 2020 May 12.

Department of Neurosurgery, Hannover Medical School, Hannover, Germany.

Objective: Despite contemporary diagnostic and therapeutic techniques intracranial emergencies in the obstetric setting pose still a major challenge for the clinicians. There are limited guidelines and differing ethical views. Multidisciplinary teams are needed to support the pregnant woman in a way that she can deliver a viable and healthy child. The aim of the present study was to scrutinize the management of intracranial emergencies during pregnancy which needed urgent neurosurgical treatment.

Patients And Methods: Data of all pregnant women who presented with newly diagnosed intracranial pathologies and neurological symptoms caused by these pathologies in an emergency setting were collected over a 10-year period (2008-2018). Patient characteristics including maternal age, gestational age, and preoperative work-up of both mother and fetus were recorded. Furthermore, the surgical treatment, mode of delivery, and neonatal and maternal outcomes were analysed.

Results: The mean maternal age was 32.7 years and most patients were in their third trimester. There was one twin pregnancy (total of 12 fetuses). Five out of eleven pregnant women suffered from intracerebral haemorrhage (epidural haematoma (1), arteriovenous malformation (1), subarachnoid haemorrhage (2) and intracerebral haemorrhage (1)) and the other six patients had intracranial neoplasms (primary meningeal sarcoma (1), trigeminal schwannoma (1), anaplastic astrocytoma (2), glioblastoma (1) and sphenoid wing meningioma (1)).Neurosurgical procedures were performed via craniotomies in eight patients. A stereotactic biopsy via a frontal burr hole was achieved one patient. The two other patients with subarachnoid haemorrhage due to rupture of PICA aneurysms were treated with coil embolization. Depending on the gestational age and the clinical condition of the pregnant women it was decided to perform an emergency Caesarean section prior to further therapeutic measures in seven patients. Two out of 12 fetuses were unviable. Six women survived, while five women succumbed to the intracranial pathology.

Conclusion: The individualized treatment approach in this peculiar obstetric scenario needs to consider various issues such as the clinical condition of the pregnant woman, prognosis of the disease, gestational age and the status of the pregnancy. The primary concern in this context must be the mother`s health and safety. Caesarean section is the primary mode of delivery in most cases. While contemporary care can insure survival for the majority of infants, maternal mortality still poses an extraordinary challenge. Interdisciplinary consulting of the patient and/or her family is necessary to develop a treatment strategy for both the expectant woman and her offspring.
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http://dx.doi.org/10.1016/j.clineuro.2020.105905DOI Listing
August 2020

Spinal Emergency Surgery During Pregnancy: Contemporary Strategies and Outcome.

World Neurosurg 2020 07 16;139:e421-e427. Epub 2020 Apr 16.

Department of Neurosurgery, Hannover Medical School, Hannover, Germany.

Background: Low back pain is a common complaint during pregnancy. However, spinal pathologies, which manifest with severe pain, radiculopathy, and acute neurologic deficits because of disk herniation or mass lesions require special attention. Here, we present our interdisciplinary experience in the surgical management of spinal emergencies during pregnancy.

Methods: The data of pregnant women who underwent surgery for spinal pathologies over a 10-year period were collected. Patient-related characteristics such as maternal age, gestational age, preoperative workup, signs and symptoms of mothers, and diagnostic procedures were evaluated. After an interdisciplinary conference, individualized treatment plans regarding available options were developed. Fetal Doppler and cardiotocography were obtained before and after surgery.

Results: Nine pregnant women presented with spinal disorders and underwent spinal emergency surgery within the study period. The mean maternal age was 32.2 years. Six women presented with lumbar disk herniations manifesting as severe sciatica or foot drop and 3 patients had thoracic mass lesions resulting in cauda equine syndrome and/or ataxia. The mean gestational age at the time of presentation was 26.5 weeks. Caesarean sections were performed in 3 women prior to the neurosurgical procedure, whereas the pregnancies were maintained in the 6 other patients. Eight infants who were healthy at birth had an unremarkable development.

Conclusions: Surgery for spinal emergencies in pregnancy can be performed safely according to individual treatment plans developed by an interdisciplinary team taking into account the expectant mother's decision. Maintenance of pregnancy is possible and feasible in most patients.
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http://dx.doi.org/10.1016/j.wneu.2020.04.019DOI Listing
July 2020

Pediatric rosette-forming glioneuronal tumor of the septum pellucidum.

Childs Nerv Syst 2020 11 26;36(11):2867-2870. Epub 2020 Mar 26.

Department of Neurosurgery, Hannover Medical School, Carl-Neuberg Str. 1, 30625, Hannover, Germany.

Rosette-forming glioneuronal tumor (RGNT) is a rare tumor entity which has been reported mainly occurring in the fourth ventricle. It has been described as a benign lesion with limited extension into surrounding structures, including the cerebellar vermis, midbrain, and cerebral aqueduct. More recently, few cases involving also other midline structures have been documented as well. Here, we report about diagnosis and treatment of RGNT in the septum pellucidum in a pediatric patient which has not been described previously. A 7-year-old boy had a 3-week history of headache. Magnetic resonance imaging showed a solid mass in the septum pellucidum accompanied by hydrocephalus. The tumor was resected via a transcortical approach. Histological examination revealed the typical findings of a RGNT. At 2-year follow-up, there was no tumor recurrence, and clinical outcome was unremarkable. RGNT has to be considered in the differential diagnosis of pediatric midline tumors also outside of the fourth ventricle. Surgical resection is the first-line therapy which may result in beneficial outcome in the long term. The role of adjuvant therapy needs further definition since due to the rarity of this tumor entity, available data is very limited.
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http://dx.doi.org/10.1007/s00381-020-04575-wDOI Listing
November 2020

The Role of Neurosurgery in the Treatment of Intracranial Tumor-Like Inflammatory Lesions.

World Neurosurg 2018 Dec 13. Epub 2018 Dec 13.

Department of Neurosurgery, Institute for Pathology, Hannover Medical School, Hannover, Germany.

Background: Different inflammatory diseases can manifest as intracranial lesions. They may be indistinguishable from intracranial neoplasms in the clinical setting, imaging studies, or laboratory studies. The value of surgery in the diagnosis and the treatment of such lesions is still unclear.

Methods: A total of 3066 reports of histopathologic examinations over a 10-year period were reviewed. Forty patients with an inflammatory intracranial lesion were identified. Clinical, radiologic, and follow-up data were analyzed and the diagnostic and therapeutic value of surgery was assessed.

Results: We identified 24 women and 16 men (mean age, 47 years). The diameter of the lesion varied between 1 and 5.5 cm (mean, 2.6 cm). The location of the inflammatory lesion was intracerebral supratentorial (n = 18, 45%), intrasellar/suprasellar (n = 5, 12.5%), cerebellar (n = 5, 12.5%), in the brainstem (n = 4, 10%), in the cerebellopontine angle (n = 3, 7.5%), meningeal (n = 3, 7.5%), and at other locations (n = 6, 15%). Seventeen patients underwent surgical removal of the mass lesion, whereas in 23 patients a biopsy was taken. The lesions were classified into 7 groups: specific (infectious) granuloma (n = 10, 25%), unspecific granuloma (n = 7, 17.5%), idiopathic inflammatory pseudotumor (n = 5, 12.5%), demyelinating lesions (n = 5, 12.5%) encapsulated hematoma (n = 4, 10%), organized cerebral infarction (n = 3, 7.5%), and vasculitis (n = 4, 10%). Surgery was judged as valuable in 35 patients (87.5%).

Conclusions: The differential diagnosis of intracranial inflammatory lesions involves a wide spectrum. Surgery has a diagnostic and/or therapeutic value in most entities and clinical circumstances. However, attention must be taken to avoid surgery without a therapeutic or diagnostic value for the patient.
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http://dx.doi.org/10.1016/j.wneu.2018.12.003DOI Listing
December 2018

A composite prepared from a metal-organic framework of type MIL-101(Fe) and morin-modified magnetite nanoparticles for extraction and speciation of vanadium(IV) and vanadium(V).

Mikrochim Acta 2018 12 12;186(1):14. Epub 2018 Dec 12.

Department of Physics, Iran University of Science and Technology, Narmak, Tehran, 16844, Iran.

A novel magnetic metal-organic framework (MOF) consisting of MIL-101(Fe) and morin-modified magnetite nanoparticles was synthesized and utilized for the extractive speciation analysis of V(IV) and V(V) at trace levels. The magnetic MOF exhibits selectivity toward V(V) at pH = 5.8. The concentration of V(IV) can be determined after its oxidation to V(V) and extracting total vanadium. After sorption and elution steps, vanadium can be determined by ETAAS. Under the optimal conditions, the limit of detection, linearity and the relative standard deviation for V(V) are 3.0 ng L, 10-750 ng L and 6.0%, respectively. The new method was validated by employing two certified reference materials. Finally, the method was successfully utilized for fast and selective speciation analysis of V(IV) and V(V) in water and food samples. Graphical abstract A novel functionalized magnetic metal-organic framework was synthesized and used for the speciation and preconcentration of trace amounts of vanadium.
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http://dx.doi.org/10.1007/s00604-018-3093-yDOI Listing
December 2018

Experimental Rat Model for Brain Death Induction and Kidney Transplantation.

J Invest Surg 2020 Feb 18;33(2):141-146. Epub 2018 Oct 18.

Department of General, Visceral, and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.

Experimental animal research has been pivotal in developing clinical kidney transplantation (KTx). One donor-associated risk factor with negative affect of transplantation outcome is brain death (BD). Many rat models for BD and KTx have been developed in the last decade, but no surgical guidelines have been developed for these models. Here, we describe a surgical technique for BD induction and the cuff technique for experimental KTx in rats. After intubation and mechanically ventilation of sixteen healthy adult male Sprague-Dawley rats were induction of BD performed. Animals were kept hemodynamically stable for eight hours. Then, the kidney was prepared and perfused with standard histidine-tryptophan-ketoglutarate solution. After explantation, grafts were immediately implanted in recipients using the cuff technique and reperfused. After 2 h of observation, animals were sacrificed by intravenous administration of potassium chloride. In the early phase of BD, heart rate increased and mean arterial pressure decreased. Partial variations were observed in O partial pressure, O saturation, and HCO. During the 2-h observation phase, all transplanted kidneys were sufficiently perfused macroscopically. There was no hyperacute rejection. It is feasible to observe BD for 8 h with maintained circulation in small experimental settings. The cuff technique for KTx is simple, the complication rate is low, and the warm ischemia time is short, therefore, this could be a suitable technique for KTx in the rat model.
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http://dx.doi.org/10.1080/08941939.2018.1480677DOI Listing
February 2020

Intracranial foreign material granulomas after cranial surgery.

Acta Neurochir (Wien) 2018 11 6;160(11):2069-2075. Epub 2018 Sep 6.

Department of Neurosurgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.

Background: Various synthetic materials are used in neurosurgery and left in place intentionally during surgery for several purposes such as hemostasis, dural closure, or cranioplasty. Although leaving such substances in surgical sites is considered safe, in general, foreign body granuloma may occur months or years after intracranial surgery. Thus, far relatively little is known about treatment and outcome of such lesions.

Methods: A systematic review of 3466 histopathological examinations after cranial surgeries achieved over a 13-year period was performed. After excluding patients with Teflon granulomas or infection, a total of 12 patients with foreign body granulomas induced by synthetic material used in a prior surgery were identified. Patient records, imaging studies, and histopathological data were analyzed. Furthermore, postoperative outcome was assessed.

Results: Mean age at the second surgery was 51 years (range, 11-68 years). The median time between the primary and the secondary surgery was 13 months (range, 1-545 months). Eight patients (75%) presented with signs and symptoms related to the foreign body granulomas. Total resection of the foreign body granulomas was performed in all patients. The granulomas were induced by oxidized cellulose polymer (n = 6), suture material (n = 3), Gelfoam (n = 1), methylmethacrylate (n = 1), and bone wax (n = 1). The mean postoperative follow-up time was 54 months (range 1-137 months). There was symptomatic improvement in all instances. Imaging studies did not demonstrate any recurrence.

Conclusion: Despite its rarity, foreign body granuloma should be taken into consideration in the differential diagnosis of intracranial mass lesions especially in cases of suspected tumor recurrence after prior surgery. The pathogenesis of foreign body granuloma still needs further clarification. Our study demonstrates that they have good prognosis after surgical removal.
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http://dx.doi.org/10.1007/s00701-018-3663-0DOI Listing
November 2018

Severe Bilateral Kinetic Tremor Due to Unilateral Midbrain Lesions.

Tremor Other Hyperkinet Mov (N Y) 2017 6;7:515. Epub 2017 Dec 6.

Department of Neurosurgery, Hannover Medical School, Hannover, Germany.

Background: The dentatothalamic tract connects the dentate nucleus of the cerebellum with the contralateral thalamus and plays a major role in the pathogenesis of tremor. Unilateral lesions of the dentatothalamic pathway may affect its ipsilateral predecussational or its contralateral postdecussational course, which results either in ipsilateral or in contralateral tremor.

Case Report: Here, we present two patients with a unilateral midbrain lesion resulting in bilateral tremor. Both patients presented with severe kinetic tremor.

Discussion: The corresponding unilateral mesencephalic lesion affected both the ipsilateral predecussational and the ipsilateral postdecussational dentatothalamic tract originating from the contralateral dentate nucleus, which is very unusual and has not been outlined clearly before.
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http://dx.doi.org/10.7916/D88G8Z8JDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5721131PMC
September 2018

Time-course of plasma inflammatory mediators in a rat model of brain death.

Transpl Immunol 2017 08 15;43-44:21-26. Epub 2017 Jul 15.

Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, 69120, Germany. Electronic address:

Background: Brain death (BD) is a donor-associated risk factor that negatively affects transplantation outcome. The inflammation associated with BD appears to have a negative effect on organ quality. Complement activation, apoptosis, and pro-inflammatory cytokine and chemokine expression are significantly increased after BD. To better understand this process, we investigated plasma chemokine and cytokine levels for 8h after BD in a rodent model.

Methods: Thirteen healthy adult male Sprague Dawley rats were intubated and mechanically ventilated. After induction of BD, animals were kept hemodynamically stable for 8h. A panel of immune response factors, including cytokines and chemokines, were measured immediately prior to the induction of BD and at 1, 4, and 8h after BD by multiplex analyses in 10 rats.

Results: In the early phase of BD, we observed an increase in heart rate and a decrease in mean arterial pressure. Only limited fluctuations were noted in the partial pressure of O, O saturation, and HCO. Monocyte-/macrophage- and lymphocyte-derived mediators (IL-2, IL-4, and IFN-γ) increased steadily during the 8-hour monitoring period.

Conclusions: The increase in immune responses, particularly pro-inflammatory responses, after BD is time-dependent. Cytokines and chemokines from donors and recipients require further investigation to determine the optimal time frames for organ transplantation in rodent models and humans.
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http://dx.doi.org/10.1016/j.trim.2017.07.001DOI Listing
August 2017

Multiple desmoplastic infantile gliomas--therapeutic challenges.

Childs Nerv Syst 2016 Jan 19;32(1):17. Epub 2015 Nov 19.

Department of Neurosurgery, Hannover Medical School, Hannover, Germany.

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http://dx.doi.org/10.1007/s00381-015-2958-1DOI Listing
January 2016

Influence of a modified preservation solution in kidney transplantation: A comparative experimental study in a porcine model.

Asian J Surg 2017 Apr 1;40(2):106-115. Epub 2015 Sep 1.

Department of Experimental Surgery, University of Heidelberg, Heidelberg, Germany.

Background/objective: Currently, due to lack of optimal donors, more marginal organs are transplanted. Therefore, there is a high interest to ameliorate preischemic organ preservation, especially for critical donor organs. In this regard, a new histidine-tryptophane ketoglutarate (HTK-N) solution has been designed and its protective efficacy was compared with the standard preservation solutions-University of Wisconsin solution and standard HTK or Custodiol (Bretschneider's solution).

Methods: Seventy-two landrace pigs were included into the study, as donors and recipients. The donor kidneys were perfused during explantation with cold University of Wisconsin solution (n = 12), standard HTK (n = 12), or HTK-N solutions (n = 12), kept in the respective preservation solution at 4°C for 30 hours, implanted in the recipient pigs, and reperfused. The pigs survived in daily control for 7 days. The serum creatinine and blood urea nitrogen were assessed in pre- and postreperfusion phase on the 3 day and 7 day posttransplantation. Additionally, tissue samples were taken to analyze the histopathological degree of tubular injury and regeneration before and after reperfusion.

Results: The three preservation groups were comparable in age, body weight, and hemodynamic parameters. According to statistical proof, they differed in none of the control parameters.

Conclusion: Although the new preservation HTK solution is in several points a well-thought-out modification of the standard HTK solution, its preservation efficacy, at least for kidney preservation in a pig model for 30 hours, seems to be comparable to the current used solutions. A real advantage, however, could be confirmed in clinical settings, where marginal organs may influence the clinical outcome.
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http://dx.doi.org/10.1016/j.asjsur.2015.07.001DOI Listing
April 2017

CLIPPERS Syndrome: An Entity to be Faced in Neurosurgery.

World Neurosurg 2015 Dec 4;84(6):2077.e1-3. Epub 2015 Aug 4.

Department of Neurosurgery, Hannover Medical School, Hannover, Germany.

Background: Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an inflammatory disorder of the central nervous system; it has only recently been defined and to date has received only limited attention. Its cause is as yet unknown. The pathologic characteristics are infiltration of T lymphocytes into the perivascular spaces of the pons, responsiveness to immunotherapy, and gadolinium-enhancing punctiform lesions in the brainstem seen on magnetic resonance imaging (MRI).

Case Description: We report here on the clinical, MRI, and brain biopsy findings in a 68-year-old man who presented with dysphagia, numbness and paresthesia on the right side of his face, as well as progressive gait ataxia. Brain and spinal MRI showed lesions in the pons and in the cervical spinal cord. The pontine lesion became progressively larger extending to the middle cerebellar peduncle and a tumor was suspected. After repeated biopsy, the histopathologic diagnosis confirmed CLIPPERS.

Conclusions: CLIPPERS syndrome may become manifest with a progressive tumor-like pontine lesion. This report adds clinical and radiologic aspects to the limited number of CLIPPERS cases reported to date, and underlines the importance of considering CLIPPERS in the differential diagnosis of tumor-like pontine processes.
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http://dx.doi.org/10.1016/j.wneu.2015.07.057DOI Listing
December 2015

Evaluation of the modified HTK solution in pancreas transplantation-An experimental model.

Asian J Surg 2016 Apr 26;39(2):66-73. Epub 2015 Jul 26.

Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany. Electronic address:

Introduction: One of the great challenges in pancreas transplantation is the ischemia reperfusion injury. It is mentioned that free oxygen and/or nitrogen radicals play a prominent role in this phase. To minimize this problem, a modified histidine-tryptophan-ketoglutarate (HTK) solution that contains modified antioxidants has been developed. Our aim was to evaluate this solution in improving the viability of the pancreas in comparison with standard HTK and University of Wisconsin (UW) solutions in a porcine model of pancreas transplantation.

Materials And Methods: Twenty-three Landrace pigs were divided into three identical groups. After a 10-hour preservation time at 4°C, the pancreas was implanted in the organs of the recipients in a standardized manner. Serum parameters were assessed prior to and after implantation on the 1(st) postoperative day, 3(rd) postoperative day, and 7(th) postoperative day. Furthermore, three biopsies were taken: prior to and after reperfusion, and on Day 7 to assess the grafts.

Results: An analysis of serum glucose among the three groups showed no significant differences. Evaluation of the insulin levels showed no significant difference between the modified and standard HTK groups; however, differences between HTK and UW were significant (p = 0.004 in favor of UW solutions). The histopathological results showed a trend of a higher grade of rejection of pancreas tissue in the UW group compared to both HTK groups.

Conclusion: The modified HTK solution could preserve the pancreas for the preservation of the graft with similar results to those observed for standard solutions without any significant difference. The trend showed that the pathological finding in the UW group was not as good as that in the modified HTK and standard HTK groups.
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http://dx.doi.org/10.1016/j.asjsur.2015.03.017DOI Listing
April 2016

An unusual cause of ventriculoperitoneal shunt infection.

JAAPA 2015 Aug;28(8):39-42

At the Hannover Medical School in Hannover, Germany, Majid Esmaeilzadeh and Ariyan Pirayesh Islamian are residents in the Department of Neurosurgery; Josef M. Lang is head of the neurosurgical ICU in the neurosurgery clinic; Mathias Hornef is a professor at the Institute for Medical Microbiology and Hospital Epidemiology; Sebastian Suerbaum is a professor and chair at the Institute for Medical Microbiology and Hospital Epidemiology; and Joachim K. Krauss is a professor and department chair of the Department of Neurosurgery. The authors have disclosed no potential conflicts of interest, financial or otherwise.

Infection associated with ventriculoperitoneal (VP) shunt implantation can be a significant problem. VP shunt infection with Serratia marcescens, a gram-negative anaerobic rod, usually is related to underlying abdominal disease. This article describes treatment of two patients suffering from a VP shunt infection with S. marcescens without underlying abdominal disease.
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http://dx.doi.org/10.1097/01.JAA.0000469445.49635.b6DOI Listing
August 2015

Endoscopic intracranial surgery enhanced by electromagnetic-guided neuronavigation in children.

Childs Nerv Syst 2015 Aug 2;31(8):1327-33. Epub 2015 May 2.

Department of Neurosurgery, Medical School Hannover, Carl-Neuberg-Str.1, 30625, Hannover, Germany,

Purpose: Navigated intracranial endoscopy with conventional technique usually requires sharp head fixation. In children, especially in those younger than 1 year of age and in older children with thin skulls due to chronic hydrocephalus, sharp head fixation is not possible. Here, we studied the feasibility, safety, and accuracy of electromagnetic (EM)-navigated endoscopy in a series of children, obviating the need of sharp head fixation.

Methods: Seventeen children (ten boys, seven girls) between 12 days and 16.8 years (mean age 4.3 years; median 14 months) underwent EM-navigated intracranial endoscopic surgery based on 3D MR imaging of the head. Inclusion criteria for the study were intraventricular cysts, arachnoid cysts, aqueduct stenosis for endoscopic third ventriculostomy (ETV) with distorted ventricular anatomy, the need of biopsy in intraventricular tumors, and multiloculated hydrocephalus. A total of 22 endoscopic procedures were performed. Patients were registered for navigation by surface rendering in the supine position. After confirming accuracy, they were repositioned for endoscopic surgery with the head fixed slightly on a horseshoe headholder. EM navigation was performed using a flexible stylet introduced into the working channel of a rigid endoscope. Neuronavigation accuracy was checked for deviations measured in millimeters on screenshots after the referencing procedure and during surgery in the coronal (z = vertical), axial (x = mediolateral), and sagittal (y = anteroposterior) planes.

Results: EM-navigated endoscopy was feasible and safe. In all 17 patients, the aim of endoscopic surgery was achieved, except in one case in which a hemorrhage occurred, blurring visibility, and we proceeded with open surgery without complications for the patient. Navigation accuracy for extracranial markers such as the tragus, bregma, and nasion ranged between 1 and 2.5 mm. Accuracy for fixed anatomical structures like the optic nerve or the carotid artery varied between 2 and 4 mm, while there was a broader variance of accuracy at the target point of the cyst itself ranging between 2 and 9 mm.

Conclusions: EM-navigated endoscopy in children is a safe and useful technique enhancing endoscopic intracranial surgery and obviating the need of sharp head fixation. It is a good alternative to the common opto-electric navigation system in this age group.
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http://dx.doi.org/10.1007/s00381-015-2734-2DOI Listing
August 2015

Desmoplastic infantile astrocytoma with multiple intracranial and intraspinal localizations at presentation.

Childs Nerv Syst 2015 Jun 1;31(6):959-64. Epub 2015 May 1.

Department of Neurosurgery, Hannover Medical School, Carl-Neuberg Street. Nr. 1, 30625, Hannover, Germany.

Purpose: Desmoplastic infantile gliomas (DIG) are rare tumors that occur in infants aged between 1 and 24 months. The tumor in general has a favorable prognosis after surgical resection. There are no treatment algorithms, however, for patients with multiple intracranial and intraspinal presentations.

Case Report: In an 11-month-old girl with a history of nystagmus, magnetic resonance imaging (MRI) demonstrated contrast-enhancing lesions in the suprasellar region, the cerebellar vermis, and the spinal axis. The tumor in the cerebellar vermis was removed via a suboccipital midline approach. The histological examination revealed a desmoplastic infantile astrocytoma (DIA) WHO grade I. Postoperatively, it was decided to adopt a wait-and-see strategy. Further development, up to 16 months after surgery, was unremarkable. Follow-up MRI showed no recurrence of the posterior fossa tumor, mild progress of the suprasellar tumor, and significant regression of the spinal tumors.

Conclusion: DIA is a rare mostly benign brain tumor found in infants. The final diagnosis always relies on histology. Surgical resection is the recommended therapy for symptomatic tumors; however, more experience is needed to develop treatment recommendations for multiple-site tumors.
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http://dx.doi.org/10.1007/s00381-015-2715-5DOI Listing
June 2015

Is microdialysis useful for early detection of acute rejection after kidney transplantation?

Int J Surg 2015 Jun 9;18:88-94. Epub 2015 Apr 9.

Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany. Electronic address:

Introduction: Acute rejection following kidney transplantation (KTx) is still one of the challenging complications leading to chronic allograft failure. The aim of this study was to investigate the role of microdialysis (MD) in the early detection of acute graft rejection factor following KTx in porcine model.

Methods: Sixteen pigs were randomized after KTx into case (n = 8, without immunosuppressant) and control groups (n = 8, with immunosuppressant). The rejection diagnosis in our groups was confirmed by histopathological evidences as "acute borderline rejection". Using MD, we monitored the interstitial concentrations of glucose, lactate, pyruvate, glutamate and glycerol in the transplanted grafts after reperfusion.

Results: In the early post-reperfusion phase the lactate level in our case group was significantly higher comparing to the control group and remained in higher levels until the end of monitoring. The lactate to pyruvate ratio showed a considerable increase in the case group during the post-reperfusion phase. The other metabolites (glucose, glycerol, glutamate) were nearly at the same levels at the end of our monitoring in both study groups.

Conclusion: The increase in lactate and lactate to pyruvate ratios seems to be an indicator for early detection of acute rejection after KTx. Therefore, MD as a minimally invasive measurement tool may help to identify the need to immunosuppression adjustment in the early KTx phase before the clinical manifestation of the rejection.
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http://dx.doi.org/10.1016/j.ijsu.2015.03.024DOI Listing
June 2015

A systematic review and meta-analysis of laparoscopic versus open distal pancreatectomy for benign and malignant lesions of the pancreas: it's time to randomize.

Surgery 2015 Jan;157(1):45-55

Department of General, Visceral, and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.

Background: Laparoscopic distal pancreatectomy is regarded as a feasible and safe surgical alternative to open distal pancreatectomy for lesions of the pancreatic tail and body. The aim of the present systematic review was to provide recommendations for clinical practice and research on the basis of surgical morbidity, such as pancreas fistula, delayed gastric empting, safety, and clinical significance of laparoscopic versus open distal pancreatectomy for malignant and nonmalignant diseases of the pancreas.

Methods: A systematic literature search (MEDLINE) was performed to identify all types of studies comparing laparoscopic distal pancreatectomy and open distal pancreatectomy. Random effects meta-analyses were calculated after critical appraisal of the included studies and presented as odds ratios or mean differences each with corresponding 95% confidence intervals.

Results: A total of 4,148 citations were retrieved initially; available data of 29 observational studies (3,701 patients overall) were included in the meta-analyses. Five systematic reviews on the same topic were found and critically appraised. Meta-analyses showed superiority of laparoscopic distal pancreatectomy in terms of blood loss, time to first oral intake, and hospital stay. All other parameters of operative morbidity and safety showed no difference. Data on oncologic radicality and effectiveness are limited.

Conclusion: Laparoscopic distal pancreatectomy seems to be a safe and effective alternative to open distal pancreatectomy. No more nonrandomized trials are needed within this context. A large, randomized trial is warranted and should focus on oncologic effectiveness, defined end points, and cost-effectiveness.
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http://dx.doi.org/10.1016/j.surg.2014.06.081DOI Listing
January 2015

A simplified technique of pancreas transplantation in a porcine model.

Eur Surg Res 2015 9;54(1-2):24-33. Epub 2014 Oct 9.

Department of General, Visceral, and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.

Background: The incidence of diabetes has been steadily increasing. The only curative option for diabetes is pancreas transplantation (PTx). Porcine models are valuable because of their anatomical and physiological similarities to human beings. Our aim is to introduce a simplified technique of PTx in a porcine model.

Methods: In Landrace pigs (n = 32), after median laparotomy, the pancreas was mobilized, and the portal and splenic veins were divided. The proper hepatic and splenic arteries and the bile duct were also prepared, and the duodenal bulb was prepared and stapled. The third portion of the duodenum was freed up to the ligament of Treitz and stapled, and the renal arteries were ligated. After systemic heparinization, the pancreas was perfused through the abdominal aorta with histidine-tryptophan-ketoglutarate solution. The portal and splenic veins were cut for evaluating the sufficiency of perfusion. Whole pancreaticoduodenal graft was procured along with an aortic jump graft containing mesenteric and celiac trunks. In recipients, after total pancreatectomy, the suprarenal inferior vena cava and infrarenal aorta were prepared for vascular anastomosis in an end-to-side manner. After pancreas reperfusion, duodenoduodenostomy was performed in an end-to-side manner.

Results: Median cold and warm ischemia times were 10 h (range, 9-14 h) and 50 min (range, 35-80 min), respectively. The hemodynamic status was stable throughout the operation. The median follow-up period was 7 days (range, 4-10). There were no major intra- and postoperative complications.

Conclusion: By using an aortic jump graft, there was no need to perform additional arterial reconstruction resulting in a short warm ischemic and operation time. End-to-side portocaval and duodenoduodenal anastomoses make this model of PTx a very feasible method for experimental evaluations.
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http://dx.doi.org/10.1159/000367844DOI Listing
August 2015

Evaluating the effects of extended cold ischemia on interstitial metabolite in grafts in kidney transplantation using microdialysis.

Langenbecks Arch Surg 2013 Jan 16;398(1):87-97. Epub 2012 Oct 16.

Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.

Purpose: During kidney transplantation (KTx), the length of cold ischemia time (CIT) and the subsequent changes in energy metabolism may lead to variations in interstitial metabolites. Using microdialysis (MD), we evaluated the effects of a short and long CIT on changes of these metabolites.

Methods: Sixteen pigs were randomized in two identical groups, one with a short CIT and the other one with a long CIT. Using MD in the transplanted grafts, we evaluated the parenchyma concentrations of glucose, lactate, pyruvate, glutamate and glycerol in different stages.

Results: We noted that during the warm ischemia time (WIT) and in the early post-reperfusion phase glucose levels increased more significantly in the long CIT group and remained high until the end of monitoring. At the end of CIT and during WIT, the long CIT group had a significantly higher glycerol level, but the level dropped gradually in the late post-reperfusion phase and reached a steady state in both groups.

Conclusions: The extended CIT clearly results in considerably impaired graft metabolism. The high interstitial glucose levels within hours after KTx could be considered as a marker of primary delayed function of the graft. Furthermore, the glycerol value could reflect the extent of graft injury during the ischemia time or in case of acute impairment of graft perfusion.
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http://dx.doi.org/10.1007/s00423-012-1010-0DOI Listing
January 2013

Technical guidelines for porcine liver allo-transplantation: a review of literature.

Ann Transplant 2012 Apr-Jun;17(2):101-10

Department of General, Visceral and Transplantation Surgery, Ruprecht-Karls-University, Heidelberg, Germany.

Experimental animal research has been pivotal in the development of clinical liver transplantation (LTx). Results obtained in these experiments have been applied in clinic and clinical challenges have been scrutinized in animal laboratories. Porcine model is an optimal model in the field of experimental LTx research. Here, we present the various techniques of experimental LTx in the porcine model in detail. Different methods and modifications have been described. The following major steps have been discussed in detail: donor liver preparation, recipient operation including recipient hepatectomy, and reconstruction phase, including the reconstruction of suprahepatic inferior vena cava (SHIVC), portal vein (PV), infrahepatic inferior vena cava (IHIVC), hepatic artery (HA) and bile duct (BD). IHIVC and SHIVC are anastomosed end to end directly or with the use of prosthesis anastomosed side to side. The PV anastomosis is performed end to end between donor and recipient PV, Cuff method or Stump method. Arterialization has been accomplished via carrel patch or donor HA end to end with recipient HA. There are three major methods for reconstruction of BD: end to end or end to side choledochocholedochostomy or choledojejunostomy with Roux-en-Y jejunal loop. Each method has advantages and disadvantages regarding the objectives of the study; the most physiological techniques may be preferred for long-term survival studies, while the faster techniques may be selected for experimentations aiming the direct postoperative phase.
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http://dx.doi.org/10.12659/aot.883228DOI Listing
November 2012

Assessment and treatment of choledocholithiasis when endoscopic sphincterotomy is not successful.

Arch Iran Med 2012 May;15(5):275-8

Department of Surgery and Research Center for Improvment of Surgical Outcomes and Procedures, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.

Background: Choledocholithiasis exists in approximately 15% of patients with gallstones and is present in 3%-10% of those undergoing cholecystectomy.

Methods: In this study, we retrospectively analyzed the outcome patients with choledocholithiasis that were managed by open common bile duct (CBD) exploration according to our center's protocol. Endoscopic retrograde cholangiopancreatography (ERCP) was performed for CBD stone clearance. If ERCP and sphincterotomy were not successful, open surgical exploration of CBD was performed with T-tube insertion without routine intraoperative cholangiography (IOC).

Results: We studied 1462 patients with choledocholithiasis. ERCP was successful in in 1276 (87.2%) patients. A total of 186 (12.8%) underwent surgery. Of these, 82 (45.2%) had CBD exploration and T-tube insertion without IOC. Choledochoduodenostomy was performed in 82 (44.1%) patients and choledochojejunostomy was performed in 20 (10.8%). Retained stones were found only in 4 cases which were treated by ERCP.

Conclusion: ERCP is successful in most cases with choledocholithiasis. If ERCP fails, open exploration of CBD and T-tube insertion, or biliary-enteric anastomosis are acceptable ways for CBD drainage. The rate of retained stone is not more than expected, thus elective IOC is more acceptable than routine IOC. Routine IOC is time-consuming and particularly difficult in elderly patients and emergency conditions.
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http://dx.doi.org/012155/AIM.006DOI Listing
May 2012

Appropriate donor size for porcine liver xenotransplant.

Exp Clin Transplant 2012 Apr;10(2):148-53

Department of General, Visceral and Transplant Surgery, University of Heidelberg, Germany.

Objectives: Owing to an imbalance between demand and supply, which is more prominent in pediatric transplant, every year more patients lose their lives on waiting lists. In addition to the use of deceased-donor split and living-donor organs, xenotransplant could provide a solution if associated problems, such as immunologic and physiologic ones, are solved. This study sought to analyze the surgical aspects for liver xenotransplant in a porcine model.

Materials And Methods: Landrace pigs (n=22, 23 to 37 kg) underwent a laparotomy under general anesthesia. The hepatic hilum was prepared and the common bile ducts, common hepatic artery, portal vein, supra- and infrahepatic inferior vena cava were identified. The length and diameter of each vessel and bile duct and the weight of the liver were measured.

Results: Pearson tests showed a clear correlation between the increase of the pigs' weight and the livers' weight, and the length of the vessels and the bile ducts. We did not find a clear correlation between the increase of the pigs' liver weight and the diameters of the vessels and the bile duct.

Conclusions: As the first reporting, this study on xenotransplants from the surgical point of view, we postulate that it could be possible to estimate the size of the liver and the proper length of its vessels and bile duct by weighing only the pigs. It was not feasible to match the diameter of mentioned structures by the livers' weight. However, the weight of pig's liver as well as vascular anatomy of pigs appeared to be suitable alternative for the human liver.
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http://dx.doi.org/10.6002/ect.2011.0102DOI Listing
April 2012

Early detection of metabolic changes using microdialysis during and after experimental kidney transplantation in a porcine model.

Surg Innov 2011 Dec;18(4):321-8

Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.

Background: Microdialysis (MD) can detect organ-related metabolic changes before they become measurable in plasma through the biochemical parameters. This study aims to evaluate the early detection of metabolic changes during experimental kidney transplantation (KTx).

Material And Methods: During preparation of 8 donor kidneys, one MD catheter was inserted in the renal cortex and samples were collected. After a 6-hour cold ischemia time (CIT), kidneys were implanted in the 8 recipient pigs. Throughout the warm ischemia time (WIT) and after reperfusion, kidneys were monitored. The interstitial glucose, lactate, pyruvate, glutamate, and glycerol concentrations were evaluated.

Results: A significant decline in glucose level was observed at the end of CIT. The lactate level was reduced to the minimum point of 0.35 ± 0.08 mmol/L in CIT. After reperfusion, lactate values raised significantly. During the WIT, the pyruvate level increased, continued until the end of the WIT. For glutamate, a steady increase was noted during explantation, CIT, WIT, and early reperfusion phases. The increase of glycerol value continued in the early postreperfusion, which was then followed by a sharp decline.

Conclusion: MD is a fast and simple minimally invasive method for measurement of metabolic substrates in renal parenchyma during KTx. MD offers the option of detecting minor changes of interstitial glucose, lactate, pyruvate, glutamate, and glycerol in every stage of KTx. Through the use of MD, metabolic changes can be continuously monitored during the entire procedure of KTx.
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http://dx.doi.org/10.1177/1553350610392063DOI Listing
December 2011

A bulking agent may lead to adrenal insufficiency crisis: a case report.

Acta Med Iran 2011 ;49(10):688-9

Department of Internal Medicine, Rasul Akram Hospital, Tehran University of Medical Science, Iran.

Adrenal insufficiency is a life-threatening disorder which must be treated with glucocorticoid replacement and needs permanent dose adjustment during patient's different somatic situations. Insufficient glucocorticoid doses result in adrenal crisis and must be treated with intravenous hydrocortisone. The patient was known with Adrenal insufficiency and was treated optimally with fludrocortisone and prednisolone since seven years with no history of adrenal crisis. The patient was admitted with abdominal pain, weakness, fatigue and nausea developed 3-4 days after taking psyllium, a bulking agent, prescribed by a surgeon to diagnose anal fissure. Detailed medical history, physical examinations, laboratory and imaging examinations did not approve any other cause of adrenal crisis. Psyllium may interfere with gastrointestinal absorption of prednisolone and/or fludrocortisone and trigger acute adrenal crisis in patients with adrenal insufficiency.
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February 2012

Using microdialysis for early detection of vascular thrombosis after kidney transplantation in an experimental porcine model.

Nephrol Dial Transplant 2012 Feb 30;27(2):541-7. Epub 2011 Jun 30.

Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.

Background: In kidney transplantation (KTx), vascular thrombosis has a major impact on morbidity and graft survival. The ischaemia, caused by thrombosis, can lead to interstitial metabolite changes. The aim of this experimental study was to create conditions in which the graft would be prone to vascular thrombosis following KTx and then to evaluate the role of microdialysis (MD) for its early detection.

Methods: Sixteen randomized pigs in the control group received heparin and immunosuppressive drugs, while the case group received none. Based on histopathological evidence of vascular thrombosis, the case group was subdivided into mildly and severely congested subgroups. Using MD, we evaluated the interstitial concentrations of glucose, lactate to pyruvate ratio, glutamate and glycerol in the transplanted grafts during different phases of KTx.

Results: Following reperfusion, we noted considerable changes. The severely congested subgroup showed a low and decreasing level of glucose. Only in this group did the lactate to pyruvate ratio continue to increase until the end of monitoring. The glycerol level increased continuously in the entire case group and this increase was most significant in the severely congested subgroup. In all of the study groups, glutamate concentration remained in a low steady state until the end of monitoring.

Conclusion: MD can be an appropriate method for early detection of vascular complications after KTx. Decreasing glucose levels, increased lactate to pyruvate ratio and increased glycerol levels are appropriate indicators for early detection of vascular thromboses following KTx. Particularly, the glycerol level could predict the necessity and urgency of intervention needed to ultimately save the transplanted kidney.
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http://dx.doi.org/10.1093/ndt/gfr308DOI Listing
February 2012

The role of HBIg as hepatitis B reinfection prophylaxis following liver transplantation.

Langenbecks Arch Surg 2012 Jun 2;397(5):697-710. Epub 2011 May 2.

Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany.

Background And Introduction: Without adequate prophylaxis, liver transplantation (LTx) is frequently followed by hepatitis B virus (HBV) reinfection, which results in rapidly progressing liver disease and significantly decreased overall survival. In the last two decades, significant progress has been made in the prophylaxis and treatment of HBV.

Discussion: We present an overview of different protocols and regimens used for prophylaxis of HBV reinfection after LTx and describe the protocol implemented at our center. Following LTx, HBV reinfection can be effectively prevented by administration of anti-hepatitis B immunoglobulin (HBIg) alone or more recently in combination with antiviral nucleoside/nucleotide analogs (NUCs). Several studies reported good results with the use of HBIg alone, but combination treatment with HBIg and NUCs has proven to be a superior prophylactic regimen for HBV recurrence. At present, combination therapy (HBIg and a nucleoside or nucleotide analog) is the gold standard used in many transplantation centers. This preventive regimen reduces the risk of a recurrence of HBV infection and thereby the need for re-transplantation. Future and ongoing studies will show how long HBIg must be given after transplantation, especially when used in combination with potent antivirals, such as entecavir or tenofovir.
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http://dx.doi.org/10.1007/s00423-011-0795-6DOI Listing
June 2012

Comparison of different surgical techniques in distal pancreatectomy: an experimental study in a porcine model.

Surg Innov 2011 Dec 8;18(4):329-37. Epub 2011 Feb 8.

University of Heidelberg, Heidelberg, Germany.

Aims: Different surgical transection methods have been used for distal pancreatectomy (DP), but none of them has yet achieved perfect results. This study compares 2 standard transection techniques with the alternative LigaSure technique.

Methods: Forty-eight pigs underwent a DP. Sixteen animals were operated on with a scalpel followed by hand suturing. Sixteen pigs received a DP using an Endo GIA, and the pancreas of 16 pigs was transected with LigaSure. The transection surface of remnant pancreas was observed for liquid collection and abscess on postoperative day 7.

Results: Operating time on the day of DP was significantly different, with a shorter operating time in the stapler and LigaSure groups. The morbidity on postoperative day 7 was similar in all groups.

Conclusion: In the present experimental animal study, LigaSure seems to be fast and safe as well as comparable with the standard transection and closure techniques in DP.
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http://dx.doi.org/10.1177/1553350610395032DOI Listing
December 2011

One life ends, another begins: Management of a brain-dead pregnant mother-A systematic review-.

BMC Med 2010 Nov 18;8:74. Epub 2010 Nov 18.

Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Germany.

Background: An accident or a catastrophic disease may occasionally lead to brain death (BD) during pregnancy. Management of brain-dead pregnant patients needs to follow special strategies to support the mother in a way that she can deliver a viable and healthy child and, whenever possible, also be an organ donor. This review discusses the management of brain-dead mothers and gives an overview of recommendations concerning the organ supporting therapy.

Methods: To obtain information on brain-dead pregnant women, we performed a systematic review of Medline, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL). The collected data included the age of the mother, the cause of brain death, maternal medical complications, gestational age at BD, duration of extended life support, gestational age at delivery, indication of delivery, neonatal outcome, organ donation of the mothers and patient and graft outcome.

Results: In our search of the literature, we found 30 cases reported between 1982 and 2010. A nontraumatic brain injury was the cause of BD in 26 of 30 mothers. The maternal mean age at the time of BD was 26.5 years. The mean gestational age at the time of BD and the mean gestational age at delivery were 22 and 29.5 weeks, respectively. Twelve viable infants were born and survived the neonatal period.

Conclusion: The management of a brain-dead pregnant woman requires a multidisciplinary team which should follow available standards, guidelines and recommendations both for a nontraumatic therapy of the fetus and for an organ-preserving treatment of the potential donor.
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http://dx.doi.org/10.1186/1741-7015-8-74DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3002294PMC
November 2010

Feasibility of a high intrathoracic esophagogastric anastomosis without thoracic access after laparoscopic-assisted transhiatal esophagectomy: a pilot experimental study.

Surg Innov 2009 Sep 27;16(3):228-36. Epub 2009 Aug 27.

Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Germany.

Introduction: The aim of the present study was to evaluate the feasibility of a technique that uses solely the transhiatal approach to create a high intrathoracic esophagogastric anastomosis after laparoscopic transhiatal resection of the distal esophagus.

Method: Using a laparoscopic approach, the esophagi of 10 midsized pigs were dissected and transected as high as possible in the thorax, and the anvil of a circular stapler was introduced perorally into the esophageal stump. Through a midline short laparotomy, the circular stapler was inserted into the gastric tube and advanced through the hiatus to be connected with the anvil and create the anastomosis.

Results: Development of the technique was completed within the first 6 experiments. The last 4 operations were entirely successful, standardized, and easily reproducible.

Conclusion: The technique is feasible in this experimental setting. Further studies are required to establish if there is a clinical role for this technique in esophageal surgery.
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http://dx.doi.org/10.1177/1553350609345852DOI Listing
September 2009