Publications by authors named "Andrew Shea Afyouni"

5 Publications

  • Page 1 of 1

Can preoperative renal mass biopsy change clinical practice and reduce surgical intervention for small renal masses?

Urol Oncol 2021 Oct 4;39(10):735.e17-735.e23. Epub 2021 Aug 4.

Department of Urology, University of California, Irvine. Electronic address:

Introduction: The role of renal biopsy prior to surgical intervention for a renal mass remains controversial despite the fact that for all other urological organs except the testicle, biopsy inevitably precedes treatment as is true for all other specialties dealing with solid masses (e.g. thyroid, breast, colon, liver, etc.). Accordingly, we sought to determine the impact of a routine biopsy regimen on the course of patients with cT1a lesions in comparison with a contemporary series of cT1a individuals who went directly to treatment without a preoperative biopsy.

Methods: We analyzed a multi-institutional, prospectively maintained database of patients who underwent an office-based, ultrasound-guided, renal mass biopsy (RMB) for a cT1a renal mass (i.e. ≤4cm in largest dimension). Controls were selected from all patients in the database who had a cT1a renal lesion but did not undergo RMB. Both groups were analyzed for differences in treatment modality and surgical pathology results.

Results: A total of 72 RMB and 73 control patients were analyzed. The groups were similar in regards to their baseline characteristics. Overall RMB diagnostic rate was 75%. Surgical pathology revealed that excision of benign tumors was eight-fold less in the RMB cohort compared to the control group (3% vs. 23%; P < 0.001). Additionally, the rate of active surveillance in the RMB cohort was nearly three times higher at 35% vs. 14% for the controls (P < 0.001). Biopsy was concordant with surgical pathology in 97% of cases for primary histology (i.e. benign vs. malignant), 97% for histologic subtype, and 46% for low (I or II) vs. high (III or IV) grade. On multivariate analysis patients who underwent surgical intervention without preoperative RMB were 6.7 times more likely to have benign histopathology compared to patients who underwent preoperative RMB (OR 6.7, 95% CI = 0.714 - 63.626, P = 0.096). There were no procedural or post-procedural RMB complications.

Conclusions: For patients with cT1a lesions, the implementation of routine office-based RMB led to a significant decrease in the rate of surgical intervention for benign tumors. This practice also resulted in a higher rate of active surveillance for the management of renal cortical neoplasms with benign histopathology compared to a control group.
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October 2021

Caveat Emptor: The Heat Is "ON": An In Vivo Evaluation of the Thulium Fiber Laser and Temperature Changes in the Porcine Kidney during Dusting and Fragmentation Modes.

J Endourol 2021 Apr 28. Epub 2021 Apr 28.

Univ. of California, Irvine, Urology, 101 The City Drive South, Bldg. 55, Room 304, Route 81, Irvine, California, United States, 92868;

Introduction: We sought to examine the intrarenal fluid and tissue temperature during dusting and fragmentation with the Thulium fiber laser (TFL) in an in vivo porcine kidney.

Methods: In two pigs, temperature was continuously measured within the upper, middle, and lower calyces and at the tip of the ureteroscope. Four experimental protocols were performed: dual lumen ureteroscope with both warmed (37°C) and room temperature (20-22ºC) irrigation and single lumen ureteroscope with warmed and room temperature irrigation. In each pig, one kidney had a 14F ureteral access sheath (UAS), other kidney had no UAS. A 200µm TFL was fired at three settings: dusting (0.5J, 80Hz, 40W) with continuous activation for 5 minutes or until a temperature reached 44⁰C; low power (1J, 10Hz, 10W) and high-power fragmentation (1.5J, 20Hz, 30W). For fragmentation, the laser was activated for 10 seconds with a 2 second intermission for 1 minute.

Results: In the absence of an UAS, in all but one circumstance, temperatures exceeded 44ºC at all settings with the use of either warm or room temperature irrigation, regardless of the type of ureteroscope. Temperatures recorded at the ureteroscope tip were 4ºC - 22ºC less than the temperatures recorded in the renal calyces. In contrast, with a 14F UAS in place, 6 distinct groups had temperatures that did not exceed 44ºC, specifically at low and high-power fragmentation settings with room temperature irrigation for both sets of ureteroscopes and at dusting and low-power fragmentation settings with warm temperature irrigation solely for the single lumen ureteroscope. Temperatures at the ureteroscope tip with an UAS yielded temperature differences from 17ºC less to 19ºC more than the renal calyces.

Conclusions: Thulium fiber laser is a novel technology for lithotripsy. In the absence of a UAS, high-power TFL fragmentation settings, may create temperatures that could result in urothelial tissue injury.
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April 2021

Spinal Anesthesia Reduces Myocardial Ischemia-triggered Ventricular Arrhythmias by Suppressing Spinal Cord Neuronal Network Interactions in Pigs.

Anesthesiology 2021 03;134(3):405-420

Background: Cardiac sympathoexcitation leads to ventricular arrhythmias. Spinal anesthesia modulates sympathetic output and can be cardioprotective. However, its effect on the cardio-spinal reflexes and network interactions in the dorsal horn cardiac afferent neurons and the intermediolateral nucleus sympathetic neurons that regulate sympathetic output is not known. The authors hypothesize that spinal bupivacaine reduces cardiac neuronal firing and network interactions in the dorsal horn-dorsal horn and dorsal horn-intermediolateral nucleus that produce sympathoexcitation during myocardial ischemia, attenuating ventricular arrhythmogenesis.

Methods: Extracellular neuronal signals from the dorsal horn and intermediolateral nucleus neurons were simultaneously recorded in Yorkshire pigs (n = 9) using a 64-channel high-density penetrating microarray electrode inserted at the T2 spinal cord. Dorsal horn and intermediolateral nucleus neural interactions and known markers of cardiac arrhythmogenesis were evaluated during myocardial ischemia and cardiac load-dependent perturbations with intrathecal bupivacaine.

Results: Cardiac spinal neurons were identified based on their response to myocardial ischemia and cardiac load-dependent perturbations. Spinal bupivacaine did not change the basal activity of cardiac neurons in the dorsal horn or intermediolateral nucleus. After bupivacaine administration, the percentage of cardiac neurons that increased their activity in response to myocardial ischemia was decreased. Myocardial ischemia and cardiac load-dependent stress increased the short-term interactions between the dorsal horn and dorsal horn (324 to 931 correlated pairs out of 1,189 pairs, P < 0.0001), and dorsal horn and intermediolateral nucleus neurons (11 to 69 correlated pairs out of 1,135 pairs, P < 0.0001). Bupivacaine reduced this network response and augmentation in the interactions between dorsal horn-dorsal horn (931 to 38 correlated pairs out of 1,189 pairs, P < 0.0001) and intermediolateral nucleus-dorsal horn neurons (69 to 1 correlated pairs out of 1,135 pairs, P < 0.0001). Spinal bupivacaine reduced shortening of ventricular activation recovery interval and dispersion of repolarization, with decreased ventricular arrhythmogenesis during acute ischemia.

Conclusions: Spinal anesthesia reduces network interactions between dorsal horn-dorsal horn and dorsal horn-intermediolateral nucleus cardiac neurons in the spinal cord during myocardial ischemia. Blocking short-term coordination between local afferent-efferent cardiac neurons in the spinal cord contributes to a decrease in cardiac sympathoexcitation and reduction of ventricular arrhythmogenesis.

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March 2021

Applications of neural networks in urology: a systematic review.

Curr Opin Urol 2020 11;30(6):788-807

Department of Urology, University of California Irvine, Orange, California, USA.

Purpose Of Review: Over the last decade, major advancements in artificial intelligence technology have emerged and revolutionized the extent to which physicians are able to personalize treatment modalities and care for their patients. Artificial intelligence technology aimed at mimicking/simulating human mental processes, such as deep learning artificial neural networks (ANNs), are composed of a collection of individual units known as 'artificial neurons'. These 'neurons', when arranged and interconnected in complex architectural layers, are capable of analyzing the most complex patterns. The aim of this systematic review is to give a comprehensive summary of the contemporary applications of deep learning ANNs in urological medicine.

Recent Findings: Fifty-five articles were included in this systematic review and each article was assigned an 'intermediate' score based on its overall quality. Of these 55 articles, nine studies were prospective, but no nonrandomized control trials were identified.

Summary: In urological medicine, the application of novel artificial intelligence technologies, particularly ANNs, have been considered to be a promising step in improving physicians' diagnostic capabilities, especially with regards to predicting the aggressiveness and recurrence of various disorders. For benign urological disorders, for example, the use of highly predictive and reliable algorithms could be helpful for the improving diagnoses of male infertility, urinary tract infections, and pediatric malformations. In addition, articles with anecdotal experiences shed light on the potential of artificial intelligence-assisted surgeries, such as with the aid of virtual reality or augmented reality.
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November 2020

Retrospective Assessment of Endoscopic Enucleation of Prostate Complications: A Single-Center Experience of More Than 1400 Patients.

J Endourol 2020 02;34(2):192-197

Institute for Urology and Reproductive Health, Sechenov University, Moscow, Russia.

Endoscopic enucleation of the prostate (EEP) is a safe method of treating benign prostatic hyperplasia, regardless of prostate volume and type of applied energy. To date, however, there has been no study that examines complication rates with respect to the type of applied energy. This study aims to address this problem by providing a retrospective analysis of >1400 patients who have undergone prostate enucleation. We performed a retrospective analysis of all patients undergoing EEP between 2013 and 2018 at a single tertiary institution. This analysis included patients who had undergone one of three forms of EEP: holmium laser enucleation of the prostate (HoLEP), thulium fiber laser enucleation of the prostate (ThuFLEP), or monopolar enucleation of the prostate (MEP). We compared intraoperative and early postoperative complications, as well as complications at 3 and 6 months follow-up. A total of 1413 patients were included in this study; 36% patients underwent HoLEP, 57.5% had ThuFLEP, and 6.5% MEP. The most frequent complication in the early postoperative period was a mild fever (2.76% of the cases). The morcellation was delayed to a separate stage because of intensive hemorrhaging in 1.4% of the cases. Bladder tamponade was found in 1.1% of the cases. We found no correlation between complication rate and either prostate volume or energy source. Stress urinary incontinence was found in 3.9% of patients at 3 months and in only 1.4% of patients at 6 months after the operation. Urethral stricture at 6 months after the surgery was found in 1.4% of patients, whereas bladder neck sclerosis was found in only 0.9% of these cases. No significant difference was observed between these complication frequencies and any preoperative factors or energy source. All EEP types are safe with equal rates of complications intraoperatively, postoperatively, and at 6 months follow-up.
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February 2020