Michael J. Conlin

Timing, Incidence and Risk Factors for Venous Thromboembolism in Patients Undergoing Radical Cystectomy for Malignancy: A Case for Extended Duration Pharmacological Prophylaxis

PURPOSE Patients undergoing radical cystectomy for bladder cancer are at high risk for venous thromboembolism. Recent data have demonstrated that the risk of venous thromboembolism often extends beyond hospital discharge in nonurological surgical populations. To our knowledge the timing of venous thromboembolism in patients who have undergone radical cystectomy during a 30-day postoperative period has not been assessed. Therefore, we evaluated the timing, incidence and risk factors for venous thromboembolism for patients undergoing radical cystectomy for malignancy. MATERIALS AND METHODS In this descriptive, observational, retrospective study data from 1,307 patients who underwent radical cystectomy for malignancy from 2005 to 2011 were collected using the American College of Surgeons NSQIP (National Surgical Quality Improvement Program) database. Venous thromboembolism occurrences were evaluated by postoperative day and whether they occurred while an inpatient or after discharge home. Univariate and multivariate Cox regression and logistic regression models were used to evaluate risk factors associated with venous thromboembolism. RESULTS Of 1,307 patients 78 (6%) were diagnosed with venous thromboembolism. The mean time to venous thromboembolism diagnosis was 15.2 days postoperatively. Of all venous thromboembolism events 55% were diagnosed after patient discharge home. The 30-day mortality rate from venous thromboembolism was 6.4%. Risk factors for the development of venous thromboembolism on multivariate analysis were age (p = 0.024), operative time (p = 0.004) and sepsis or septic shock (p = 0.0001). CONCLUSIONS More than half of all venous thromboembolisms (55%) in patients undergoing radical cystectomy for malignancy occurred after discharge home and the mean time to venous thromboembolism diagnosis was 15.2 days postoperatively. It is reasonable to consider extended duration pharmacological prophylaxis (4 weeks) in this high risk surgical population.

URETEROSCOPY: Development and Instrumentation

Advances in ureteroscope and working instrument designs now allow the treatment of a variety of upper urinary tract disorders in a minimally invasive fashion. This field has benefited from the close cooperation between endourologists, engineers, and manufactures. Continued cooperation should result in even further improvements in ureteroscopic instrumentation. This article also presents the development of flexible and rigid ureteroscopes and working instruments. Knowledge of these features can assist the urologist in choosing the most appropriate tool for different ureteroscopic tasks.

Poly-IC preconditioning protects against cerebral and renal ischemia-reperfusion injury

Preconditioning induces ischemic tolerance, which confers robust protection against ischemic damage. We show marked protection with polyinosinic polycytidylic acid (poly-IC) preconditioning in three models of murine ischemia-reperfusion injury. Poly-IC preconditioning induced protection against ischemia modeled in vitro in brain cortical cells and in vivo in models of brain ischemia and renal ischemia. Further, unlike other Toll-like receptor (TLR) ligands, which generally induce significant inflammatory responses, poly-IC elicits only modest systemic inflammation. Results show that poly-IC is a new powerful prophylactic treatment that offers promise as a clinical therapeutic strategy to minimize damage in patient populations at risk of ischemic injury.

Efficacy and safety of low molecular weight heparin in renal transplantation

BACKGROUND Deep venous thrombosis (DVT) is a common problem with potentially devastating results in patients undergoing major surgical procedures. Certain renal transplant recipients are particularly at risk for allograft loss as a consequence of renal vein and artery thrombosis. Over the past few years, low molecular weight heparin has been well established as an accepted modality of treatment and prophylaxis of DVT. The efficacy and safety of low molecular weight heparin in the prophylaxis of DVT following renal transplantation in adults has not previously been reported. METHODS Dalteparin was administered to 120 adult renal transplant recipients postoperatively at the Oregon Health Sciences University. RESULTS No patient developed allograft arterial or venous thrombosis. One patient developed subclavian vein thrombosis. No bleeding complications were encountered, and side effects were very minimal. CONCLUSION Prophylaxis with dalteparin is an effective and safe modality for the prevention of thrombosis in adult patients undergoing renal transplantation.

Ureteroscopically assisted percutaneousrenal access

Percutaneous nephrostolithotomy is a common procedure for removing kidney stones. Obtaining percutaneous access can be difficult in some patients. We describe our technique of ureteroscopically assisted percutaneous renal access for patients in whom standard percutaneous access may be challenging.

Update on Flexible Ureteroscopy

Objective: An update on ureteroscopy with focus on current technology and newer instrumentation is presented. Methods: A literature search through Medline-indexed journals as well as personal comments are included in this review. Topics such as new semirigid and flexible ureteroscopes, lasers, ureteral access sheats, wires and stone extraction devices are outlined. Results: Thanks to the continuous advances of technology and miniaturization of instruments, ureteroscopy is an ever-expanding field. A clear outline of the available instruments and techniques with reference to published results catches the status of this dynamic field. Conclusions: Urologists are faced with a host of new products related to ureteroscopy every year. This review serves to identify the most useful and proven advances in the field and helps in selecting the equipment needed for a successful minimally invasive approach to upper urinary tract pathologies.

Ureteric access with flexible ureteroscopes: effect of the size of the ureteroscope.

To determine the optimum size of a flexible ureteroscope (FU) to minimize the need for ureteric dilatation.

Results of Selective Management of Ureteropelvic Junction Obstruction

BACKGROUND AND PURPOSE Controversy continues over the need to image the ureteropelvic junction (UPJ) before endopyelotomy to detect crossing vessels. We evaluated a selective management model for UPJ obstruction. PATIENTS AND METHODS Intraoperative ultrasonography was performed before endopyelotomy in 19 men and 16 women. Patients with large (>4-mm) crossing vessels underwent open or laparoscopic pyeloplasty; the others had ureteroscopic or percutaneous endopyelotomy with electrocautery or the holmium laser. RESULTS Crossing vessels were found in 25 of the 35 patients and a high-inserting ureter in 4. The vessels were >4 mm in nine patients, seven of whom had successful pyeloplasty and two of whom were managed expectantly with good results. Endopyelotomy was successful in 94% without a crossing vessel and 70% of those with a crossing vessel. The overall success rate (absence of symptom and resolution of obstruction on renal scintigraphy) was 89%. CONCLUSION Selective management of UPJ obstruction, avoiding endopyelotomy in the presence of a large crossing vessel, appears to improve the success rate.

The Current Role of Endourologic Management of Renal Transplantation Complications

Introduction. Complications following renal transplantation include ureteral obstruction, urinary leak and fistula, urinary retention, urolithiasis, and vesicoureteral reflux. These complications have traditionally been managed with open surgical correction, but minimally invasive techniques are being utilized frequently. Materials and Methods. A literature review was performed on the use of endourologic techniques for the management of urologic transplant complications. Results. Ureterovesical anastomotic stricture is the most common long-term urologic complication following renal transplantation. Direct vision endoureterotomy is successful in up to 79% of cases. Urinary leak is the most frequent renal transplant complication early in the postoperative period. Up to 62% of patients have been successfully treated with maximal decompression (nephrostomy tube, ureteral stent, and Foley catheter). Excellent outcomes have been reported following transurethral resection of the prostate shortly after transplantation for patients with urinary retention. Vesicoureteral reflux after renal transplant is common. Deflux injection has been shown to resolve reflux in up to 90% of patients with low-grade disease in the absence of high pressure voiding. Donor-gifted and de novo transplant calculi may be managed with shock wave, ureteroscopic, or percutaneous lithotripsy. Conclusions. Recent advances in equipment and technique have allowed many transplant patients with complications to be effectively managed endoscopically.

Treatment of biliary calculi using holmium: yttrium aluminum garnet laser

BACKGROUND The holmium: yttrium aluminum garnet laser (Ho: YAG) has been shown to be effective and safe for the treatment of urinary calculi. Its effectiveness for the treatment of biliary calculi was investigated. METHODS Endoscopic Ho: YAG lithotripsy of biliary stones was performed 7 times in 4 patients. Two patients had biliary duct calculi, and the other two patients had gall bladder calculi. All patients had multiple calculi that ranged in size from 4 mm to 5 cm. All procedures were performed percutaneously under intravenous sedation and local anesthesia. Rigid and flexible endoscopes were used to access the biliary calculi. Postoperative cholangiograms were performed on all patients. RESULTS All calculi were successfully fragmented with the Ho: YAG laser. The most common settings on the laser were 1.0 J and 10 Hz. Average total laser energy used was 12.24 kJ. Two patients required multiple procedures for the resolution of the biliary calculi. No vascular or biliary injuries were encountered. Three patients were free of biliary calculi on their postoperative cholangiogram. One patient with multiple gallbladder stones refused further treatment after two percutaneous procedures. CONCLUSION The holmium: yttrium aluminum garnet laser can be used safely and effectively in the endoscopic treatment of biliary calculi. This treatment maybe a suitable option in patients who are not candidates for more invasive procedures.