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Biomedical subjects

Sam B Bhayani

Publications and source records attributed to Sam B Bhayani.

48 records · Page 3Linked to original sources

Laparoscopic partial nephrectomy: effect of warm ischemia on serum creatinine.

PURPOSE: Laparoscopic partial nephrectomy (LPN) has been shown to be a safe and effective option for small renal tumors. However, limited data are available regarding the effect of warm ischemic time on postoperative renal function. We assessed the effect of variable durations of warm ischemia on long-term renal function in patients undergoing LPN. MATERIALS AND METHODS: A total of 118 patients with a single, unilateral, sporadic renal tumor and normal contralateral kidney underwent LPN from August 1998 to November 2002. Patients were divided into 3 groups based on warm ischemic time, namely group 1-no renal occlusion in 42, group 2-warm ischemia less than 30 minutes in 48 and group 3-warm ischemia greater than 30 minutes in 28. All 3 groups were assessed for changes in serum creatinine 6 months after LPN. Additionally, renal remnants were examined with cross-sectional imaging. RESULTS: At a median followup of 28 months (range 6 to 56) median creatinine had not statistically increased postoperatively. None of the 118 patients progressed to renal insufficiency or required dialysis after LPN. CONCLUSIONS: Based on postoperative serum creatinine warm ischemia time up to 55 minutes does not significantly influence long-term renal function after LPN. Thus, during LPN efforts to minimize warm ischemia are important but they should not jeopardize cancer control, hemostasis or collecting system closure.

Adult↗

Nerve sparing radical prostatectomy: effects of hemostatic energy sources on the recovery of cavernous nerve function in a canine model.

PURPOSE: To preserve sexual function following radical prostatectomy, one must avoid injury to the neurovascular bundles (NVBs). In the conventional open surgical technique, the use of energy sources for hemostasis is avoided to prevent damage to the cavernous nerves. In contrast, during laparoscopic radical prostatectomy, electrosurgical and ultrasonic energy sources are frequently used for hemostasis during dissection of the prostate. In this study, we evaluated the acute and chronic physiological effects of various hemostatic energy sources on cavernous nerve function in the canine model. MATERIALS AND METHODS: A total of 12 dogs were divided into 4 groups based on the type of energy source used for hemostasis during unilateral dissection of the NVB. The groups included conventional dissection with suture ligatures (group 1), monopolar (group 2) or bipolar (group 3) electrosurgery and ultrasonic shears (group 4). The contralateral NVB was left undissected as a control. Erectile function was assessed acutely and after 2 weeks of survival by measuring peak intracavernous pressures in response to cavernous nerve stimulation. RESULTS: Following conventional techniques of nerve sparing, the erectile response to nerve stimulation was unaffected. In contrast, the use of energy sources in proximity to the NVB during nerve preservation was associated with a substantial decrease in erectile response both acutely (74% to 91% decrease compared to controls) and after 2 weeks (93% to 96% decrease). CONCLUSIONS: In the chronic canine model, use of hemostatic energy sources in proximity to the prostate during dissection of the neurovascular bundle is associated with a significantly decreased erectile response to cavernous nerve stimulation.

Animals↗

Prospective comparison of short-term convalescence: laparoscopic radical prostatectomy versus open radical retropubic prostatectomy.

OBJECTIVES: To evaluate and compare prospectively the convalescence of patients after laparoscopic radical prostatectomy (LRP) and open radical retropubic prostatectomy (RRP) in a standardized clinical care pathway at a single institution by two surgeons of equal experience and training. METHODS: The study included all 60 patients undergoing LRP and RRP by two fellowship-trained surgeons in their first year of practice. The postoperative care of these patients was uniform and standardized. The medical records were reviewed and convalescence data obtained by an independent urologist and physician's assistant. RESULTS: Of the 60 patients, 24 underwent RRP and 36 underwent attempted LRP; 3 patients were converted from LRP to RRP. The differences in mean age, preoperative prostate-specific antigen level, Gleason score, in-hospital morphine equivalent requirement, time to oral intake, and hospital stay were not statistically significant between the LRP and RRP groups. The operating room time was significantly longer (5.8 +/- 1.2 hours versus 2.8 +/- 0.55 hours, P <0.0001) and the estimated blood loss was significantly lower in the LRP group (533 +/- 212 mL versus 1473 +/- 768 mL, P <0.0001) than in the RRP group. Pain medication use at home was significantly less in the LRP group (9 +/- 13 versus 17 +/- 15 oxycodone tablets, P <0.04), as was the time to complete convalescence (30 +/- 18 days versus 47 +/- 21 days, P <0.002). CONCLUSIONS: Although LRP took almost twice as long to complete as RRP in our initial clinical experience, the patients had a similar hospital course. LRP patients required less pain medication after discharge and had a shorter time to complete recovery than did RRP patients. Additional studies are needed to address long-term cancer control, potency, and continence outcomes to determine the precise role of LRP in the treatment of men with clinically localized prostate cancer.

Convalescence↗

Laparoscopic retroperitoneal lymph node dissection for clinical stage I nonseminomatous germ cell testicular cancer: a long-term update.

OBJECTIVES: To assess retrospectively the long-term cancer control in patients undergoing laparoscopic retroperitoneal lymph node dissection (RPLND) in the management of clinical Stage I nonseminomatous germ cell testicular tumors. METHODS: A retrospective review of 29 patients undergoing laparoscopic RPLND was performed. All patients had clinical Stage I nonseminomatous germ cell testicular tumor, with vascular invasion and/or embryonal carcinoma in the orchiectomy specimen. A modified template dissection was performed. Patients with retroperitoneal metastases were offered two cycles of chemotherapy. A modified follow-up schedule was used in patients with pathologically negative nodes. RESULTS: Lymph nodes were negative in 17 of 29 patients. Of these 17 patients, 15 had no recurrence and were free of disease with 5.8 years of follow-up. Two patients had recurrence, one in the chest, and one biochemically, and both were free of disease after chemotherapy. Twelve of 29 patients had lymph nodes with metastatic testicular cancer. Ten of these patients underwent adjuvant chemotherapy and were free of disease with 6.3 years of follow-up. One patient had a biochemical recurrence after positive RPLND and was salvaged with chemotherapy. One patient was observed after positive RPLND and was free of disease with 4.9 years of follow-up. The only long-term complication was retrograde ejaculation in 1 patient. CONCLUSIONS: Laparoscopic RPLND is a safe, minimally invasive treatment option in patients with clinical Stage I nonseminomatous germ cell testicular tumor. The cancer control appears to be similar, with minimal morbidity compared with the open procedure.

Adult↗

Surgical treatment of renal neoplasia: evolving toward a laparoscopic standard of care.

OBJECTIVES: To determine the extent to which laparoscopy has replaced open surgery for renal malignancy. METHODS: The records of all 537 patients at Washington University who underwent surgery for localized renal malignancies from January 1997 to December 2001 were examined for clinical and pathologic information. RESULTS: The total procedures per year increased from 1997 to 2001, but the distribution of pathologic stages throughout the 5 years was similar. In 1997, laparoscopic approaches were used in 15% of cases; this increased to 65% by 2001. Nephron-sparing surgery (NSS) was used in 31% to 42% of patients yearly, but laparoscopic NSS increased in frequency. By 2001, only 3.3% of T1 tumors were removed by open radical nephrectomy compared with 55% treated by laparoscopic nephrectomy. The rest of the T1 tumors in 2001 were treated by open partial nephrectomy (20.2%) or laparoscopic NSS (21.3%). In 2001, 61% of T2 lesions were treated laparoscopically, an increase from 37% in 1997. Most open radical nephrectomies in 2001 were performed for T3 disease. The number of surgeons performing laparoscopic renal surgery has increased at our institution, from two in 1997, both endourologists, to eight in 2001, representing the entire urology faculty that treats renal cancer. CONCLUSIONS: Laparoscopic radical nephrectomy has replaced open radical nephrectomy for low-stage renal neoplasia. Although laparoscopic NSS is increasing in frequency, it has not yet replaced open partial nephrectomy. At our institution, the laparoscopic approach has become the standard of care when radical nephrectomy is needed for T1 or T2 renal cancer.

Carcinoma, Renal Cell↗

Bipolar needle electrocautery for laparoscopic partial nephrectomy without renal vascular occlusion in a porcine model.

OBJECTIVES: To report a novel method of accomplishing laparoscopic lower pole partial nephrectomy in an acute porcine model using a bipolar needle electrode without the need for renal arterial occlusion. METHODS: Six animals (12 renal units) underwent laparoscopic polar nephrectomy using the bipolar needle electrode. After complete laparoscopic mobilization of the lower pole of the kidney, the bipolar needle electrode was repeatedly inserted full-thickness into the renal parenchyma and applied transversely, creating regional ischemia to the entire lower pole without renal vascular occlusion. The specimen was then amputated using laparoscopic scissors. RESULTS: For the 12 laparoscopic partial nephrectomies, the mean operative time was 39 +/- 30 minutes, and the mean blood loss was 90 +/- 112 mL. Of the 12 cases, 10 (83%) were performed successfully with the bipolar needle electrocautery as the only source of hemostasis and without the need for ancillary hemostatic measures. Two of the procedures (17%) required temporary arterial control for hemostasis. For the successful procedures, the mean operative time was 29 +/- 4 minutes, and the mean blood loss was 48 +/- 11 mL. Histologic analysis of the specimens demonstrated coagulative necrosis between 2 and 4 mm from the line of the surgical incision. CONCLUSIONS: Bipolar needle electrocautery is a promising device that can be used to facilitate laparoscopic partial nephrectomy with minimal blood loss and without the need for renal arterial occlusion and warm ischemia. Additional studies are required to optimize the delivery parameters of this device.

Animals↗

Transplant ureter stricture: Acucise endoureterotomy and balloon dilation are effective.

PATIENTS AND METHODS: Eight patients with ureteral stricture after renal transplantation underwent minimally invasive treatment with Acucise incision or balloon dilation. Acucise endoureterotomy was used to treat four patients with strictures at the ureterovesical anastomosis, and balloon dilation was used to treat four patients with a ureteroureterostomy stricture. Success was defined as an acceptable serum creatinine concentration in the absence of hydronephrosis with at least 1 year of follow-up. RESULTS: Acucise endoureterotomy for ureterovesical anastomosis stricture was successful in two of three patients (67%) with a mean follow-up of 20 months. One patient had an indeterminate outcome. Balloon dilation of strictured ureteroureterostomy was successful in three of four patients (75%) with a mean follow-up of 23.7 months. Three of the four patients with previously failed open revision were treated successfully with endourologic techniques. The two patients in whom treatment failed had strictures >/=1.5 cm and manifested comorbidities including diabetes mellitus. CONCLUSION: As our results are comparable to those of other published series, endourologic management of transplant ureteral stenosis is a reasonable strategy.

Adult↗

Bare naked baskets: optimizing ureteroscopic stone extraction.

Baskets placed through the working channels of flexible ureteroscopes limit mobility and irrigant flow. We describe a new technique to minimize these limitations. An unsheathed "bare naked" basket affords enhanced ureteroscopic efficacy by limiting obstruction of the working channel. We have used the technique clinically to treat stones in difficult locations successfully and to remove fragments of calculi after ureteroscopic lithotripsy.

Equipment Design↗

Use of gelatin matrix to rapidly repair diaphragmatic injury during laparoscopy.

Iatrogenic diaphragmatic injury during laparoscopy has necessitated intracorporeal suturing and occasionally thoracostomy tube placement. We describe a technique to repair the diaphragm quickly using a novel gelatin thrombin matrix. The matrix can be administered through a trocar or hand-assist device and can rapidly seal small injuries, obviating the need for formal suture repair. The presented case and technique should be considered in selected small diaphragmatic injuries.

Carcinoma, Renal Cell↗

Laparoscopic RPLND for clinical stage I nonseminomatous germ cell testicular cancer: current status.

The purpose of the study was to update the current status of laparoscopic retroperitoneal lymph node dissection in the treatment of clinical Stage I nonseminomatous germ cell testicular cancer. A literature search was conducted to evaluate laparoscopic retroperitoneal lymph node dissection (RPLND) in comparison to other modalities of treatment. All treatment modalities are effective in treating clinical Stage I nonseminomatous germ cell tumors. Morbidity is the major issue that may guide treatment decisions. Laparoscopic RPLND, in its therapeutic form, may replicate open RPLND with a minimally invasive approach. Laparoscopic RPLND is an effective alternative to traditional treatment options.

Humans↗