Metabolic Syndrome and Nephrolithiasis Risk: Should the Medical Management of Nephrolithiasis Include the Treatment of Metabolic Syndrome?

This article reviews the relationship between metabolic syndrome (MetS) and nephrolithiasis, as well as the clinical implications for patients with this dual diagnosis. MetS, estimated to affect 25% of adults in the United States, is associated with a fivefold increase in the risk of developing diabetes, a doubling of the risk of acquiring cardiovascular disease, and an increase in overall mortality. Defined as a syndrome, MetS is recognized clinically by numerous constitutive traits, including abdominal obesity, hypertension, dyslipidemia (elevated triglycerides, low high-density lipoprotein cholesterol), and hyperglycemia. Urologic complications of MetS include a 30% higher risk of nephrolithiasis, with an increased percentage of uric acid nephrolithiasis in the setting of hyperuricemia, hyperuricosuria, low urine pH, and low urinary volume. Current American Urological Association and European Association of Urology guidelines suggest investigating the etiology of nephrolithiasis in affected individuals; however, there is no specific goal of treating MetS as part of the medical management. Weight loss and exercise, the main lifestyle treatments of MetS, counter abdominal obesity and insulin resistance and reduce the incidence of cardiovascular events and the development of diabetes. These recommendations may offer a beneficial adjunctive treatment option for nephrolithiasis complicated by MetS. Although definitive therapeutic recommendations must await further studies, it seems both reasonable and justifiable for the urologist, as part of a multidisciplinary team, to recommend these important lifestyle changes to patients with both conditions. These recommendations should accompany the currently accepted management of nephrolithiasis.

Tips and tricks of laparoscopic partial nephrectomy.

The field of urology has embraced minimally invasive surgical procedures, from endoscopic to laparoscopic to robotic assisted surgery. As these surgical techniques are applied to renal cancer, the oncological outcomes need to be compared to more traditional open surgery. Laparoscopic partial nephrectomy emulates the open surgical technique and has become an alternative to open surgery at many academic centers. Still its wide spread adoption has been limited by the challenges of renal mass extirpation and renal reconstruction in a timely fashion to limit renal ischemia. The following review is designed to assist the urologic surgeon in performing a successful laparoscopic partial nephrectomy by detailing the "tips and tricks" of the procedure.

Laparoscopic renal biopsy: a 9-year experience.

OBJECTIVES: To present our experience and outcome of consecutive laparoscopic renal biopsy over a 9-year period, as renal biopsy remains an important diagnostic procedure for evaluating proteinuria, haematuria and renal failure, but when percutaneous biopsy is contraindicated, a laparoscopic biopsy is an attractive option because it is minimally invasive. PATIENTS AND METHODS: Seventy-four patients (29 male, 45 female, mean age 45 years, range 3-79) had a laparoscopic renal biopsy taken for various indications, e.g. morbid obesity, solitary kidney, coagulopathy, failed percutaneous biopsy, high location of the kidney and poor visualization with ultrasonography. The kidney was approached via a laparoscopic retroperitoneal route using a two-port technique, with the patient in the flank position. After identifying the kidney, one to five cortical biopsies were obtained with cup-biopsy forceps. RESULTS: Adequate tissue was obtained in 96% of the patients; the mean (range) operative duration was 123 (9-261) min and the estimated blood loss 67 (5-2000) mL. Forty-three patients were discharged within 24 h. Complications occurred in 10 patients, with significant bleeding in three. One patient died after surgery, secondary to a perforated peptic ulcer while on high-dose steroid therapy. CONCLUSION: Laparoscopic renal biopsy is a safe and effective alternative to open renal biopsy for patients in whom percutaneous biopsy is not feasible. It offers the advantage of obtaining cortical biopsies and achieving haemostasis under direct vision. Adequate renal tissue is obtained in most cases. Recovery and convalescence are short for most patients.

Recurrent bleeding from intercostal arterial pseudoaneurysm after retroperitoneal laparoscopic radical nephrectomy.

We report a case of a 59-year-old man with recurrent bleeding after retroperitoneal laparoscopic nephrectomy. Computed tomography and Doppler ultrasonography confirmed an intercostal artery pseudoaneurysm as the source. Angiography 1 month later demonstrated resolution after conservative management.

Laparoscopic radical nephrectomy: cancer control for renal cell carcinoma.

PURPOSE: We evaluated the clinical efficacy of laparoscopic versus open radical nephrectomy in patients with clinically localized renal cell carcinoma. MATERIALS AND METHODS: Between 1991 and 1999, 67 laparoscopic radical nephrectomies were performed for clinically localized, stages cT1/2 NXMX, pathologically confirmed renal cell carcinoma. During this period 54 patients who underwent open radical nephrectomy with pathologically confirmed stages pT1/2 NXMX disease were also identified. Medical and operative records were retrospectively reviewed and telephone followup was done to assess patient status. RESULTS: In the laparoscopic and open groups average tumor size was 5.1 (range 1 to 13) and 5.4 cm. (range 0.2 to 18), respectively, which was not statistically significant. No patient had laparoscopic port site, wound or renal fossa tumor recurrence in either group. All patients were followed at least 12 months. In the laparoscopic group 2 cancer specific deaths occurred at a mean followup of 35.6 months. In the open group there were 2 cancer specific deaths and 3 cases of disease progression at a mean followup of 44 months. Kaplan-Meier disease-free survival and actuarial survival analysis revealed no significant differences in the laparoscopic and open radical nephrectomy groups. Also, no differences were noted in the complication rate. CONCLUSIONS: Laparoscopic radical nephrectomy is an effective alternative for localized renal cell carcinoma when the principles of surgical oncology are maintained. Initial data show shorter patient hospitalization and effective cancer control with no significant difference in survival compared with open radical nephrectomy.

Measurement of bio-impedance with a smart needle to confirm percutaneous kidney access.

PURPOSE: The traditional method of percutaneous renal access requires freehand needle placement guided by C-arm fluoroscopy, ultrasonography, or computerized tomography. This approach provides limited objective means for verifying successful access. We developed an impedance based percutaneous Smart Needle system and successfully used it to confirm collecting system access in ex vivo porcine kidneys. MATERIALS AND METHODS: The Smart Needle consists of a modified 18 gauge percutaneous access needle with the inner stylet electrically insulated from the outer sheath. Impedance is measured between the exposed stylet tip and sheath using Model 4275 LCR meter (Hewlett-Packard, Sunnyvale, California). An ex vivo porcine kidney was distended by continuous gravity infusion of 100 cm. water saline from a catheter passed through the parenchyma into the collecting system. The Smart Needle was gradually inserted into the kidney to measure depth precisely using a robotic needle placement system, while impedance was measured continuously. RESULTS: The Smart Needle was inserted 4 times in each of 4 kidneys. When the needle penetrated the distended collecting system in 11 of 16 attempts, a characteristic sharp drop in resistivity was noted from 1.9 to 1.1 ohm m. Entry into the collecting system was confirmed by removing the stylet and observing fluid flow from the sheath. This characteristic impedance change was observed only at successful entry into the collecting system. CONCLUSIONS: A characteristic sharp drop in impedance signifies successful entry into the collecting system. The Smart Needle system may prove useful for percutaneous kidney access.

Percutaneous endoscopic management of urothelial tumors of the renal pelvis.

Although nephroureterectomy remains the reference standard for the treatment of transitional cell cancer of the renal pelvis, advances in technology and techniques have made percutaneous management of select lesions feasible. We report our technique of staged percutaneous resection of a large renal pelvic transitional cell cancer.

Laparoscopic ablation of symptomatic parenchymal and peripelvic renal cysts.

OBJECTIVES: To assess the safety and efficacy of laparoscopic ablation of symptomatic renal cysts as minimally invasive therapeutic techniques have largely supplanted open surgical intervention for the treatment of symptomatic renal cysts. METHODS: The records of 32 consecutive adult patients who underwent laparoscopic ablation of renal cysts (11 peripelvic, 21 parenchymal) were retrospectively reviewed. All patients were symptomatic at presentation; 26 had a single cyst, 5 had two cysts, and 1 had four cysts. RESULTS: Twenty patients underwent a transperitoneal laparoscopic approach, and 12 patients underwent a retroperitoneal laparoscopic approach. An average of 3.2 ports were used for each procedure, and no open conversions or transfusions were necessary. When comparing patients with parenchymal and peripelvic cysts, statistically significant differences were noted in the mean operative time (164 versus 233 minutes, respectively; P = 0.003) and mean operative blood loss (98 versus 182 mL, respectively; P = 0.04). Four patients (13%) had complications (one major and three minor), including a persistent ureteral stricture. One patient with negative preoperative aspiration cytology and negative intraoperative frozen section analysis was later found to have malignancy within the cyst wall, necessitating radical nephrectomy and trocar site excision. One patient (3%) developed a recurrence. CONCLUSIONS: Laparoscopic ablation of symptomatic renal cysts is a safe and efficacious procedure. We report an overall complication rate of 13% and a recurrence rate of 3% with a mean follow-up of 18.1 months (median 10.0).

Hemostatic laparoscopic partial nephrectomy: initial experience with the radiofrequency coagulation-assisted technique.

OBJECTIVES: The techniques for hemostasis after renal tumor excision have limited the widespread application of laparoscopic partial nephrectomy (LPN). To improve hemostasis and aid visualization, we report our experience with a novel radiofrequency coagulation (RFC) technique for LPN. METHODS: Ten patients underwent RFC-assisted LPN. The demographic and perioperative data were tabulated. Patients were positioned as for laparoscopic nephrectomy, and laparoscopic ports were placed. The kidney within Gerota's fascia was mobilized, and the fat overlying the tumor was carefully removed for pathologic evaluation. Under laparoscopic guidance, a radiofrequency probe was percutaneously inserted into the lesion and deployed to coagulate the lesion and a margin of normal parenchyma. Laparoscopic scissors were used to excise the lesion; additional hemostatic maneuvers were used selectively. RESULTS: The mean renal tumor size was 2.1 cm (range 1.0 to 3.2). The median operative time was 170 minutes and the median blood loss was 125 mL. The RFC technique resulted in complete tissue coagulation within the treated volume, thereby facilitating intraoperative visualization, minimizing blood loss, and permitting rapid and controlled tumor resection. The renal architecture was preserved, allowing accurate diagnosis of renal cell carcinoma and angiomyolipoma in 9 and 1 cases, respectively. No perioperative complications occurred. CONCLUSIONS: The use of RFC is an effective method to facilitate LPN of both exophytic and endophytic masses. By coagulating a margin of normal parenchyma, the technique minimizes blood loss and improves visualization during LPN. We anticipate this technique will broaden the clinical application for LPN.

Prospective double-blind study of effect of ketorolac administration after laparoscopic urologic surgery.

BACKGROUND AND PURPOSE: To decrease postoperative dependence on narcotics for analgesia, we have evaluated ketorolac as an adjunct to perioperative pain control in patients undergoing laparoscopic urologic surgery. PATIENTS AND METHODS: Sixty-five patients (34 male, 31 female) were randomized to receive either ketorolac tromethamine (15-30 mg IV q 6 h) or placebo prior to laparoscopic surgery. Patient-controlled analgesia in the form of morphine sulfate was provided. Operative factors such as the type of surgery, operative time, and estimated blood loss were recorded. Postoperative factors such as analog pain score (range 0-10), narcotic usage, and length of stay were evaluated. RESULTS: Fifty-five patients completed the study. The average pain score was 2.2 and 4.5 for the ketorolac and placebo groups, respectively (P < 0.005). The mean amounts of total morphine used were 39.2 mg (ketorolac) and 62.5 mg (placebo) (P = 0.077). The length of stay was not significantly different in the ketorolac (2.5 days) and placebo (2.6 days) groups (P = 0.74). Operative times (P = 0.21) and estimated blood loss (P = 0.60) were not significantly different in the two groups. Ketorolac did not adversely affect renal function; serum creatinine changes were not significantly different from those in the patients receiving placebo (P = 0.50). Laparoscopic pyeloplasty necessitated more narcotic analgesia than did other laparoscopic procedures (P = 0.05). CONCLUSION: Ketorolac decreases the subjective perception of pain after laparoscopic urologic surgery. It is suggested that ketorolac administration decreases the amount of narcotic usage as well. Time to resumption of oral intake and length of hospital stay were not influenced by use of ketorolac.

Laparoscopic nephroureterectomy for the treatment of transitional cell carcinoma of the upper urinary tract.

OBJECTIVES: To establish the safety and efficacy of laparoscopic and laparoscopic-assisted nephroureterectomy. METHODS: Since 1993, 25 patients with a minimum of 12 months of follow-up underwent nephroureterectomy using a total laparoscopic or laparoscopic-assisted technique. Four patients had specimen morcellation for tissue removal. All patients had regular follow-up with physical examinations, interval cystoscopy, and radiographs, depending on the metastatic potential of the tumor. Retrospective chart review was performed and assessed for operative time, blood loss, tumor pathologic stage, complications, and outcome. One patient was excluded because of an open conversion due to multiple previous abdominal surgeries and failure to progress. RESULTS: The mean operating time was 329 minutes but decreased with experience. The median hospital stay was 4 days. Tumor stage was directly related to tumor grade. Associated bladder tumors (prior history or recurrent tumors) occurred in 50% of the patients. Ipsilateral ureteral stump site recurrence occurred in 1 patient. Although no port site seeding occurred, 1 patient, whose tumor was discovered histologically after laparoscopic pyeloplasty for presumed benign disease, developed recurrence in the renal fossa and metastatic disease. Two patients developed liver metastasis. CONCLUSIONS: Total laparoscopic and laparoscopic-assisted nephroureterectomy are acceptable alternatives to open surgery in the treatment of transitional cell carcinoma of the upper urinary tract. Tumor morcellation did not appear to adversely affect patient outcome. As with open nephroureterectomy, tumor grade is the most important prognostic indicator of local, bladder, and metastatic recurrence. No port site seeding was observed in either the total laparoscopic or laparoscopic-assisted groups.

Feasibility of telementoring between Baltimore (USA) and Rome (Italy): the first five cases.

BACKGROUND AND PURPOSE: Telemedicine is the use of telecommunication technology to deliver healthcare. Telementoring has been developed to allow a surgeon at a remote site to offer guidance and assistance to a less-experienced surgeon. We report on our experience during laparoscopic urologic procedures with mentoring between Rome, Italy, and Baltimore, USA. MATERIAL AND METHODS: Over a period of 3 months, two laparoscopic left spermatic vein ligations, one retroperitoneal renal biopsy, one laparoscopic nephrectomy, and one percutaneous access to the kidney were telementored. Transperitoneal laparoscopic cases were performed with the use of AESOP, a robotic for remote manipulation of the endoscopic camera. A second robot, PAKY, was used to perform radiologically guided needle orientation and insertion for percutaneous renal access. In addition to controlling the robotic devices, the system provided real-time video display for either the laparoscope or an externally mounted camera located in the operating room, full duplex audio, telestration over live video, and access to electrocautery for tissue cutting or hemostasis. RESULTS: All procedures were accomplished with an uneventful postoperative course. One technical failure occurred because the robotic device was not properly positioned on the operating table. The round-trip delay of image transmission was less than 1 second. CONCLUSION: International telementoring is a feasible technique that can enhance surgeon education and decrease the likelihood of complications attributable to inexperience with new operative techniques.

Plain abdominal x-ray versus computerized tomography screening: sensitivity for stone localization after nonenhanced spiral computerized tomography.

PURPOSE: Urolithiasis followup with plain abdominal x-ray requires adequate visualization of the calculus on the initial x-ray or computerized tomography (CT) study. We compared the sensitivity of plain abdominal x-ray versus CT for stone localization after positive nonenhanced spiral CT. MATERIALS AND METHODS: We evaluated 46 consecutive nonenhanced spiral CT studies positive for upper urinary tract lithiasis for which concurrent plain abdominal x-rays were available. X-ray and CT studies were compared for the ability to visualize retrospectively a stone given its location by CT. A consensus of 1 radiologist and 3 urologists was reached in each case. Cross-sectional stone size and maximum length were measured on plain abdominal x-ray. RESULTS: Plain abdominal x-ray and scout CT had 48% (22 of 46 cases) and 17% (8 of 46) sensitivity, respectively, for detecting the index stone (p <0.00004). Of the 39 stones overall visualized on plain abdominal x-ray only 19 (49%) were visualized on scout CT. Mean cross-sectional area and length of the stones on scout CT were 0.34 cm.2 (approximately 6 x 5.5 mm.) and 6. 5 mm., respectively, while the average size of those missed was 0.11 cm.2 (approximately 4 x 3 mm.) and 3.6 mm. The mean size differences in the groups were highly significant (p <0.0009). CONCLUSIONS: Plain abdominal x-ray is more sensitive than scout CT for detecting radiopaque nephrolithiasis. Of the stones visible on plain abdominal x-ray 51% were not seen on CT. To facilitate outpatient clinic followup of patients with calculi plain abdominal x-ray should be performed when a stone is not clearly visible on scout CT.

Endovascular gastrointestinal stapler device malfunction during laparoscopic nephrectomy: early recognition and management.

PURPOSE: Controlled ligation and division of the renal hilum are critical steps during any nephrectomy procedure. The use of the endovascular gastrointestinal anastomosis (GIA) stapling device for control of the renal vessels during laparoscopic nephrectomy has become standard practice. However, malfunction can lead to serious consequences which require emergency conversion to an open procedure. We report our experience with GIA malfunction during laparoscopic nephrectomy. MATERIALS AND METHODS: From July 1993 to September 1999, 565 patients underwent laparoscopic nephrectomy at 2 institutions for benign and malignant diseases, and for live renal donation. Retrospective chart reviews and primary surgeon interviews were conducted to determine etiology of failure, intraoperative management and possible future prevention. RESULTS: Malfunction occurred in 10 cases (1.7%). In 8 cases the renal vein was involved and malfunctions affected the renal artery in 2. The estimated blood loss ranged from 200 to 1,200 cc. Open conversions were necessary in 2 cases (20%). The etiology of the failure included primary instrument failure in 3 cases and preventable causes in 7. Open surgery was required in 2 patients and laparoscopic management was possible in 8. CONCLUSIONS: The endovascular GIA stapler is useful in performing laparoscopic nephrectomy. However, malfunctions may occur, and can be associated with significant blood loss and subsequent need for conversion to an open procedure. The majority of errors could be avoided with careful application and recognition. Many failures, especially when recognized before release of the device, can be managed without conversion to an open procedure.

Mini-percutaneous nephrolithotomy.

Standard percutaneous nephrolithotomy is highly effective for the removal of renal calculi. However, significant morbidity has been associated with this procedure. Consequently, many urologists inappropriately defer to a less effective procedure to reduce patient morbidity. This practice may increase the total number of procedures needed for treatment and result in a substantial increase in health care costs. Mini-percutaneous nephrolithotomy using a 13F ureteroscopy sheath is described to reduce the morbidity associated with standard percutaneous nephrolithotomy while maintaining its efficiency and effectiveness for stone removal. The indications and technique for mini-percutaneous nephrolithotomy and our results are summarized.