Endourologic management of duodenal calculi in pancreas-kidney transplantation.

Duodenal stones formed during pancreas-kidney transplantation are usually associated with nonabsorbable sutures or staples. We report on the delayed formation of a struvite duodenal stone not attributed to foreign material, managed successfully with intracorporeal electrohydraulic lithotripsy.

Laparoscopic pyeloplasty: current status.

OBJECTIVE: To review current publications and report our results and long-term follow-up of laparoscopic transperitoneal pyeloplasty for pelvi-ureteric junction (PUJ) obstruction. PATIENTS AND METHODS: In all, 147 laparoscopic transperitoneal pyeloplasties were performed between August 1993 and November 2000 (mean patient age 35.7 years, range 10-85). All patients were diagnosed with PUJ obstruction by symptoms and intravenous urography, radionuclide diuretic renography or ultrasonography. An Anderson-Hynes dismembered pyeloplasty (106), Y-V plasty (28), Fenger plasty (11) and others (two) were used, according to the intraoperative findings. Twenty-five patients had secondary obstruction, having had previous surgery to the PUJ. The mean (range) follow-up was 24 (3-84) months; all patients were followed clinically and radiologically. RESULTS: The mean operative duration time was 246 (100-480) min and estimated blood loss was 158 mL. Crossing vessels were identified in 80 cases. The success rate for all, primary and secondary patients was 95%, 98% and 84%, respectively. With one exception, all failures occurred within 6 months. Twenty-one patients (22 renal units) had simultaneous laparoscopic pyeloplasty and lithotomy; they were treated successfully and all have an intact PUJ, and 20 renal units (90%) were stone-free. The overall complication rate was 8.8%. CONCLUSIONS: This series has comparable success rates to those of open pyeloplasty and the morbidity was minimal. Laparoscopic pyeloplasty may soon become the standard operation for PUJ obstruction, especially with crossing vessels.

Urethral stricture after pancreas-kidney transplantation due to polypoid urethritis.

Urologic complications are common after pancreas-kidney transplantation using bladder drainage. We report a case of urethral stricture caused by polypoid urethritis occurring 4 years after simultaneous pancreas-kidney transplantation. Endoscopic exploration revealed irregular, ragged-appearing urethral mucosa. The diagnosis of polypoid urethritis was confirmed histopathologically.

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.

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.

Telerounding and patient satisfaction after surgery.

BACKGROUND: Technologic advances in communications have facilitated the development and diffusion of telemedicine. Most applications have focused on remote outpatient management of medical conditions. We assessed the impact of introducing remote video conferencing during the immediate postoperative period (telerounds) on patient-reported satisfaction with their hospitalization. STUDY DESIGN: Between October 2002 and June 2003,85 patients undergoing elective laparoscopic or percutaneous urologic procedures were enrolled in a trial testing the impact of telerounds on patients' satisfaction with their hospitalization. Participants were entered into one of three postoperative care arms: standard once-daily attending bedside rounds; standard once-daily attending level bedside rounds plus one afternoon telerounding visit; or a substitution of one daily bedside round with a robotic telerounding visit. Participants completed a validated patient satisfaction survey 2 weeks after hospital discharge. RESULTS: Eighty-five individuals (100% response rate) completed the questionnaire. With responses dichotomized to "excellent" or "other," patients in the telerounding arm demonstrated statistically substantial improvements in ratings of examination thoroughness, quality of discussions about medical information, postoperative care coordination, and attending physician availability. Patients in the robotic telerounding arm indicated considerably higher satisfaction with regard to physician availability. After adjusting for age differences, ratings of each of the previously listed aspects of care remained notably improved in the telerounding arm. CONCLUSIONS: Telerounding either as an additional visit or as a substituted bedside visit is associated with increased patient satisfaction in postoperative care. This type of interaction appears to acceptably facilitate physician communication with hospitalized patients.

Tumor capacitance: electrical measurements of renal neoplasia.

PURPOSE: Studies have demonstrated that biological tissues possess unique electrical properties. We evaluate the electrical properties of renal tumors using a specialized probe with the capability of measuring intra-tissue capacitance in an ex vivo model of fresh surgically excised tissue. MATERIALS AND METHODS: An electrical monitoring device was used to measure tissue capacitance at a frequency of 1 MHz on 34 ex vivo kidney specimens freshly obtained after surgical excision. Tissue capacitance was promptly measured in the excised tumor as well as surrounding normal parenchyma and fat. Dielectric permittivity in each tissue was calculated using the measured capacitance data. These data were compared and correlated to pathological findings. RESULTS: The final pathology on the 34 specimens revealed 28 renal cell carcinomas (RCC), 3 oncocytomas and 3 angiomyolipomas. In patients with RCC dielectric permittivity of tumor tissue was 1.43 +/- 0.39 times greater than that of surrounding normal parenchyma (p < 0.001). The average tumor-to-normal tissue dielectric permittivity ratio for RCC was significantly greater than that for angiomyolipoma (1.43 +/- 0.39 vs 0.73 +/- 0.77, p < 0.05) but similar to that for oncocytoma (1.43 +/- 0.39 vs 1.63 +/- 0.77, p = 0.39). CONCLUSIONS: Tissue capacitance measurements may be used to differentiate renal tumor from surrounding normal tissue. In vivo studies will ultimately determine the clinical use of this technology in localizing renal neoplasms and differentiating between malignant and benign tissues.

Management of secondary ureteropelvic junction obstruction after failed primary laparoscopic pyeloplasty.

PURPOSE: Laparoscopic pyeloplasty has been established as a minimally invasive alternative to open pyeloplasty. However, little is known about the treatment of patients in whom this technique fails. We present our experience with treating ureteropelvic junction obstruction after failed primary laparoscopic pyeloplasty. MATERIALS AND METHODS: From August 1993 to September of 2003, 227 patients underwent laparoscopic pyeloplasty for primary ureteropelvic junction obstruction. Of these patients 10 (4.4%), including 6 females and 4 males 24 to 62 years old (mean age 42.1), underwent secondary treatment after laparoscopic pyeloplasty failed. The type of secondary intervention varied by anatomical factors, and patient and surgeon preference. Success was defined as symptomatic relief and improved radiographic imaging at latest followup. RESULTS: Secondary interventions were repeat laparoscopic pyeloplasty in 1 patient, retrograde endoscopic balloon dilation in 2 and endopyelotomy in 7 (laser, cold knife and cutting balloon endopyelotomy in 3, 2, and 2, respectively). No postoperative complications were seen. Patients were followed for a mean of 25.5 months (range 3 to 96) after the second procedure. Seven of 10 secondary interventions (70%) were successful with no obstruction on followup imaging. Three of 10 interventions (30%) failed, namely 1 laparoscopic pyeloplasty, 1 endoscopic balloon dilation and 1 laser endopyelotomy. Failure of the second procedure occurred at a mean of 9.3 months. CONCLUSIONS: When given the choice, most patients select endoscopic management after failed primary laparoscopic pyeloplasty due to its minimally invasive nature and low complication rate. Success rates are 70% with repeat intervention. Some patients require a third intervention.

Evaluation of water jet morcellation as an alternative to hand morcellation of renal tissue ablation during laparoscopic nephrectomy: an in vitro study.

OBJECTIVES: To evaluate the feasibility and safety of morcellation with a new prototype device that uses high-pressure water flow as a cutting/ablating tool and compare it with standard manual morcellation. METHODS: Ten porcine kidneys were morcellated with the new water jet device and ten with conventional manual morcellation. Morcellation in all cases was performed in commercially available entrapment bags. The two groups were evaluated for morcellation time, fragment size, and perforation rates (macroscopic and microscopic). RESULTS: The kidney size in both groups was similar. Morcellation was significantly (P <0.0001) faster in the water jet morcellator group than in the hand morcellation group (5.6 versus 11.9 minutes). The macroscopic evaluation after filling the entrapment bags with normal saline revealed 4 (40%) and 2 (20%) pinhole perforations in the water jet and hand morcellation groups, respectively. The microscopic evaluation revealed an 80% perforation rate in the water jet group and a 20% rate in the hand morcellator group. The size of the resulting fragments in the water jet group was not available, because the morcellated kidney was transformed in a semiliquid form. Therefore, cytology evaluation of the tissue was not possible. CONCLUSIONS: Water jet technology can be used to morcellate renal porcine tissue effectively. It is faster, but the problems of safety and histologic evaluation must be solved before this promising technology can be used in a clinical setting.

Laparoscopic management of ureteropelvic junction obstruction in patients with upper urinary tract anomalies.

PURPOSE: We report our experience with the laparoscopic management of ureteropelvic junction obstruction in patients with upper urinary tract abnormalities. MATERIALS AND METHODS: Between July 1994 and May 2002, 7 men and 4 women with upper urinary tract anatomical abnormalities were referred to our institution for management of symptomatic ureteropelvic junction obstruction. Anomalies included horseshoe kidneys in 5 cases, pelvic kidneys in 3, a pancake kidney in 1, a malrotated kidney in 1 and a duplicated collecting system in 1. Three patients had associated renal stones that were extracted during reconstruction. Mean patient age was 37.4 years (range 25 to 60). One patient had undergone a previously unsuccessful endopyelotomy and 2 had a history of abdominal surgery. RESULTS: Mean operative time was 195 minutes (range 85 to 403) and mean estimated blood loss was 122 cc (range 20 to 300). No patient in this series required transfusion. Average length of hospital stay was 3.2 days (range 2 to 5). Renal function failed to improve after surgery in 1 patient with poor renal function and severe hydronephrosis. The remaining 10 patients (91%) had durable clinical and/or radiographic success during a followup of 32.6 and 21.3 months, respectively. There were no major complications. CONCLUSIONS: Laparoscopic pyeloplasty is an effective treatment alternative for ureteropelvic junction obstruction associated with renal or urinary tract anomalies.

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.

Laparoscopic renal surgery after spontaneous retroperitoneal hemorrhage.

PURPOSE: We assessed the role of laparoscopic management in patients following spontaneous retroperitoneal hemorrhage from a renal tumor. MATERIALS AND METHODS: A retrospective chart review revealed 4 patients with spontaneous retroperitoneal hemorrhage treated at our institution in the last 2 years. After conservative management elsewhere patients were referred for definitive therapy. Patient characteristics and tumor size were examined and correlated with ease of surgical dissection and surgical outcome. No patient had any history of trauma. Computerized tomography was used to identify the initial extent of hemorrhage in all patients. RESULTS: All patients underwent successful laparoscopic exploration without the need for open conversion. Three patients underwent radical nephrectomy and 1 underwent laparoscopic partial nephrectomy. Renal hemorrhage extending outside of the renal capsule was associated with significantly more adhesions than renal hemorrhage confined to the renal capsule. Mean patient age was 56 years (range 36 to 70). Mean retroperitoneal tumor size was 5.3 cm (range 2.5 to 10). Three renal hematomas were extracapsular and 1 was subcapsular. Mean operative time was 182.3 minutes (range 59 to 235). Average estimated blood loss was 800 cc (range 150 to 2,100). CONCLUSIONS: Nontraumatic retroperitoneal hemorrhage of renal origin may be managed using traditional laparoscopic techniques with results similar to those achieved with open renal exploration. These cases may prove technically challenging due to fibrosis and associated tissue plane loss.

Optimization of the Erbium:YAG laser for precise incision of ureteral and urethral tissues: in vitro and in vivo results.

BACKGROUND AND OBJECTIVES: Tissue damage during endoscopic treatment of urethral and ureteral strictures may result in stricture recurrence. The Erbium:YAG laser ablates soft tissues with minimal peripheral damage and may be a promising alternative to cold knife and Holmium:YAG laser for precise incision of urological strictures. STUDY DESIGN/MATERIALS AND METHODS: Optimization of the Er:YAG laser was conducted using ex vivo porcine ureteral and canine urethral tissues. Preliminary in vivo studies were also performed in a laparoscopic porcine ureteral model with exposed ureter. Laser radiation with a wavelength of 2.94 microm, pulse lengths of 8, 70, and 220 microseconds, output energies of 2-35 mJ, fluences of 1-25 J/cm2, and pulse repetition rates of 5-30 Hz, was delivered through 250-microm and 425-microm core germanium oxide optical fibers in direct contact with tissue. RESULTS: Ex vivo perforation thresholds measured 2-4 J/cm2, with ablation rates of 50 microm/pulse at fluences of 6-11 J/cm2. In vivo perforation thresholds were approximately 1.8 J/cm2, with the ureter perforated in less than 20 pulses at fluences greater than 3.6 J/cm2. Peripheral thermal damage in tissue decreased from 30 to 60 microm to 10-20 microm as the laser pulse length decreased from 220 to 8 microseconds. Mechanical tissue damage was observed at the 8 microseconds pulse duration. CONCLUSIONS: The Er:YAG laser, operating at a pulse duration of approximately 70 microseconds, a fluence greater than approximately 4 J/cm2, and a repetition rate less than 20 Hz, is capable of rapidly incising urethral and ureteral tissues with minimal thermal and mechanical side-effects.

Optical access trocar injuries in urological laparoscopic surgery.

PURPOSE: Inadvertent injuries during trocar and Veress needle placement are a rare but potentially serious complication of laparoscopic surgery. An access alternative is an optical trocar under direct vision. Limited data are available regarding the safety of this technique. We reviewed complications related to optical access trocars during standard transperitoneal urological laparoscopic procedures performed at a single institution. MATERIALS AND METHODS: From 1995 to 2001 the optical access trocar was used as the initial trocar in 1,283 urological laparoscopic procedures. The procedures included simple and radical nephrectomy in 309 cases, donor nephrectomy in 386, partial nephrectomy in 79, pyeloplasty in 173 and various other procedures in 336. Intra-abdominal complications caused by optical access trocar were assessed. RESULTS: The optical trocar was inserted at the umbilicus in 88 patients (7.4%), in the right upper quadrant in 445 (34.7%) and in the left upper quadrant in 750 (58.5%). There were 4 injuries (0.31%) associated with the optical access trocar. Complications occurred on the left side in 3 cases and on the right side in 1, including 1 injury to bowel, 1 mesenteric injury resulting in a retroperitoneal hematoma and 2 injuries to epigastric vessels. Three cases were recognized and repaired immediately but in a case of epigastric vessel injury the expanding abdominal wall hematoma required postoperative repair. CONCLUSIONS: Optical access trocars provide a safe and rapid technique for initial trocar placement. Results of this large series support the finding that few trocar related complications are associated with the optical access trocar.

Management of obliterated urinary segments using a laser fiber for access.

PURPOSE: We describe a modification of the cut to the light and core-through procedures using a laser fiber to gain through and through access for treatment of complete occlusion of the ureter or urethra. MATERIALS AND METHODS: Three patients presented with complete obliteration of the ureter (2) and vesicourethral anastomosis (1). In each case the laser fiber was advanced through the obliterated segment under direct vision and then exchanged for a standard guide wire using an open ended catheter. RESULTS: Through and through access was obtained in all 3 cases and allowed subsequent incision for repair. In all 3 patients the area of incision was stented and urinary continuity was restored. CONCLUSIONS: Loss of access can lead to complications and termination of any endoscopic procedure. Use of the laser fiber to incise through the obliterated segment and subsequently act as a guide wire in our experience minimized the possibility for loss of access. The disadvantage is the cost of the laser fiber, which cannot be reused. Use of a laser fiber as a guide wire can be a viable and effective option for gaining access across strictures when alternative methods fail.