Ravi Munver

CRITICAL ANALYSIS OF SUPRACOSTAL ACCESS FOR PERCUTANEOUS RENAL SURGERY

PURPOSEnPercutaneous renal surgery is currently performed for complex renal calculi as well as for various other endourological indications. In many patients an upper pole nephrostomy tract allows direct access to most of the intrarenal collecting system. Upper pole percutaneous access may be obtained via the supracostal or subcostal approach. The preferred route depends on the location and size of the specific stone or lesion. Previously others have cautioned against the supracostal approach above the 12th rib and many have discouraged an approach above the 11th rib due to concern about the increased risk of intrathoracic complications. We retrospectively assessed the morbidity associated with supracostal percutaneous renal surgery and compared and analyzed the morbidity of the supracostal and subcostal approaches.nnnMATERIALS AND METHODSnThe records of all patients who underwent upper pole percutaneous renal surgery between November 1993 and July 1999 were retrospectively reviewed. A total of 240 patients underwent percutaneous renal procedures, including 225 for managing symptomatic renal or ureteral stones, that is nonstaghorn calculi in 157, staghorn calculi in 41, proximal ureteral calculi in 12, calculi within a caliceal diverticulum in 6, calculi associated with primary ureteropelvic junction obstruction in 5 and calculi associated with a retained ureteral stent in 4. An additional 15 procedures were done for ureteropelvic junction obstruction (7), intrarenal collecting system tumors (5), a caliceal diverticulum without stones (1), a retained ureteral stent (1) and a ureteral stricture (1).nnnRESULTSnA total of 300 nephrostomy tracts were placed to obtain access to the intrarenal collecting system via the supracostal approach in 98 (32.7%) cases and the subcostal approach in 202 (67.3%). Of the supracostal approaches 72 (73.5%) tracts were above the 12th and 26 (26.5%) were above the 11th rib. The overall complication rate irrespective of percutaneous approach was 8.3% (16.3% for supracostal and 4.5% for subcostal access). Complications included blood transfusion in 7 patients, intraoperative hemothorax/hydrothorax in 5, sepsis/bacteremia in 3, atrial fibrillation in 2, delayed nephropleural fistula in 2, renal artery pseudoaneurysm in 2, deep venous thrombosis/pulmonary embolus in 2, pneumothorax in 1 and subcapsular hematoma in 1. Seven of 8 intrathoracic complications (87.5%) developed in supracostal cases.nnnCONCLUSIONSnPercutaneous renal surgery remains an important option for managing complex renal calculi and other upper urinary tract lesions. In our experience it is generally associated with low morbidity. The supracostal approach is often preferred for obtaining intrarenal access to complex renal and proximal ureteral pathology. Because supracostal access tracts are associated with significantly higher intrathoracic and overall complication rates compared to subcostal access tracts, this approach must be used with caution when no other alternatives are available.

Routine ureteral stenting is not necessary after ureteroscopy and ureteropyeloscopy: a randomized trial.

BACKGROUND AND PURPOSEnRetrospective studies have suggested that routine stenting can be avoided following ureteroscopy. We prospectively analyzed the need for routine ureteral stent placement in patients undergoing ureteroscopic procedures.nnnPATIENTS AND METHODSnFifty-five consecutive patients (60 renal units) were randomized into either a stent or a no-stent group following ureteroscopy with either a 7.5F semirigid or a 7.5F flexible ureteroscope for treatment of calculi (holmium laser or pneumatic lithotripsy) or transitional-cell carcinoma (holmium laser). Intraoperative variables assessed included total stone burden, the need for ureteral dilation, and overall operative times. All patients were evaluated by questionnaire on postoperative days 0, 1, and 6 with regard to pain, frequency, urgency, dysuria, and hematuria.nnnRESULTSnOf the 60 renal units treated, 38 received ureteral stents (mean 5.2 days), and 22 were treated without a stent. All 10 patients requiring ureteral balloon dilation had stents placed and were removed from the analysis. There was no significant difference between the groups with regard to age, sex, or stone burden. Operative time was decreased in the no-stent group (43 minutes v 55 minutes; P = 0.013). Flank discomfort was significantly less common in the no-stent group on days 0, 1, and 6 (P = 0.004, P = 0.003, P < 0.001, respectively), as was the incidence of suprapubic pain on day 6 (P = 0.002). There was no difference in urinary frequency, urgency, or dysuria between the groups on postoperative day 1, but all these symptoms were significantly reduced in the no-stent group on day 6 (P < 0.001, P < 0.001, P = 0.002, respectively). There was no significant difference in patient-reported postoperative hematuria in either group. One patient in each group developed a urinary tract infection. One patient in the no-stent group developed ureteral obstruction in the postoperative period that necessitated stenting, and one patient in the stent group experienced stent migration necessitating removal.nnnCONCLUSIONSnRoutine ureteral stenting does not appear to be warranted in those patients who do not require ureteral dilation during ureteroscopic procedures. Ureteral stent placement following ureteroscopy may be avoided, thereby reducing operative time, surgical costs, and patient morbidity.

Nitinol stone retrieval-assisted ureteroscopic management of lower pole renal calculi.

OBJECTIVESnCurrent ureteroscopic intracorporeal lithotripsy devices and stone retrieval technology allow for the treatment of calculi located throughout the intrarenal collecting system. Difficulty accessing lower pole calculi, especially when the holmium laser fiber is used, is often encountered. We retrospectively reviewed our experience with cases in which lower pole renal calculi were ureteroscopically managed by holmium laser fragmentation, either in situ or by first displacing the stone into a less dependent position with the aid of a nitinol stone retrieval device.nnnMETHODSnThirty-four patients (36 renal units) underwent ureteroscopic treatment of lower pole renal calculi between April 1998 and November 1999. Lower pole stones less than 20 mm were primarily treated by ureteroscopic means in patients who were obese, in patients who had a bleeding diathesis, in patients with stones resistant to shock wave lithotripsy, and in patients with complicated intrarenal anatomy, or as a salvage procedure after failed shock wave lithotripsy. Lower pole calculi were fragmented with a 200-micrometer holmium laser fiber by way of a 7.5F flexible ureteroscope. For those patients in whom the laser fiber reduced the ureteroscopic deflection, precluding re-entry into the lower pole calix, a 3.2F nitinol basket or a 2.6F nitinol grasper was used to displace the lower pole calculus into a more favorable position, allowing easier fragmentation.nnnRESULTSnIn 26 renal units, routine in situ holmium laser fragmentation was successfully performed. In the remaining 10 renal units, a nitinol device was passed into the lower pole, through the ureteroscope, for stone displacement. Only a minimal loss of deflection was seen. Irrigation was significantly reduced by the 3.2F nitinol basket, but improved with the use of the 2.6F nitinol grasper. This factor did not impede stone retrieval in any of the patients. At 3 months, 85% of patients were stone free by intravenous urography or computed tomography.nnnCONCLUSIONSnUreteroscopic management of lower pole calculi is a reasonable alternative to shock wave lithotripsy or percutaneous nephrolithotomy in patients with low-volume stone disease. If the stone cannot be fragmented in situ, nitinol basket or grasper retrieval, through a fully deflected ureteroscope, allows one to reposition the stone into a less dependent position, thus facilitating stone fragmentation.

Endoscopic Management of Symptomatic Caliceal Diverticula: A Retrospective Comparison of Percutaneous Nephrolithotripsy and Ureteroscopy

BACKGROUND AND PURPOSEnA myriad of minimally invasive options exist for managing symptomatic caliceal diverticula, including shockwave lithotripsy, percutaneous surgery, retrograde ureteroscopy, and laparoscopy. Yet no direct comparisons have been made in the literature of the relative treatment efficacy of ureteroscopy (URS) and percutaneous nephrolithotripsy (PNL). A retrospective review of our patients was performed to determine the most appropriate endoscopic management option for patients with symptomatic caliceal diverticula.nnnPATIENTS AND METHODSnBetween November of 1994 and April 2001, 39 patients presented with symptomatic caliceal diverticula, 37 of which contained calculi. Twenty-two patients (56%) underwent PNL, and 17 patients (44%) were managed by URS. Of the PNL group, 82% required the creation of a neoinfundibulotomy. The stone burden in the PNL group averaged 11.4 x 12.0 mm and that in the URS group 12.7 x 13.0 mm (p > 0.05). Pain, recurrent urinary tract infections, and nausea and vomiting were the presenting complaints in both subgroups of patients, with pain being by far the most common symptom. The average hospital stay was 2.8 days for the PNL group. All the URS procedures were performed on a same-day-surgery basis. Results, including stone-free, symptom-free, and complication rates, were compared for the two groups.nnnRESULTSnThirty-five percent of the URS group were symptom free at 6 weeks follow-up, with an additional 29% reporting an improvement in pain, whereas 86% of the PNL group was completely symptom free at 6 weeks follow-up. Only 19% of the URS group were stone free on follow-up intravenous urography v 78% of those undergoing PNL (three patients failed to return for follow-up imaging). It was not possible to identify the ostium of the stenotic infundibulum in 4 patients (24%) undergoing URS, and 7 patients (41%) eventually went on to PNL with ultimate success. The PNL was statistically better than URS in producing stone-free results for diverticula located in the upper pole and for stones <11 mm (p < 0.05). No complications occurred in the URS group; however, complications were identified in four patients after PNL. One patient developed clot urinary retention necessitating Foley catheterization and manual bladder irrigation; one patient experienced significant bleeding necessitating early cessation of the procedure. Two patients sustained intrathoracic complications, one a pneumothorax and the other a pneumohemothorax after supra-11(th) rib access. Both were managed successfully with tube thoracostomy.nnnCONCLUSIONSnOur review clearly suggests an advantage of percutaneous management over ureteroscopy for complex posterior symptomatic caliceal diverticula, although with a slightly increased risk of complications. Therefore, PNL should be considered the primary modality for managing these difficult processes. In cases where the stenotic infundibulum cannot be traversed with a guidewire, creation of a neoinfundibulotomy permitted secure access to the collecting system while providing effective results.

Acoustic and mechanical properties of artificial stones in comparison to natural kidney stones.

PURPOSEnStandardized and reproducible artificial kidney stone models are important for performing comparative studies of different lithotripsy modalities. The acoustic and mechanical properties of renal calculi dictate the manner by which stones interact with the mechanical stresses produced by shock wave lithotripsy (SWL) or intracorporeal lithotripsy modalities. We have developed a novel artificial kidney stone model that is made of natural substances found in real kidney stones. These stone models appear to be much closer in physical properties to natural kidney stones than previously used stone models.nnnMATERIALS AND METHODSnThe acoustic and mechanical properties of six groups of artificial stone models were compared to corresponding natural stones of similar compositions. Moreover, three groups of artificial stone models made of plaster-of-Paris were compared to their natural counterparts. In terms of acoustic properties, stone density was measured using a pycnometer based on Archimedes principle, whereas longitudinal and transverse (or shear) wave propagation speeds were measured using an ultrasound pulse transmission technique. These values were used to calculate wave impedance and dynamic mechanical properties (bulk modulus, Youngs modulus, and shear modulus) of the stones. The microhardness of the stones was measured and the effect of composition on stone fragility was evaluated.nnnRESULTSnArtificial stones, when compared to natural stones of similar composition, showed similar trends in longitudinal and transverse wave speeds, wave impedance, and dynamic elastic moduli. However, values for the artificial stones were uniformly low compared to those of natural stones, suggesting that these artificial stones may be more amenable to shock wave fragmentation. The results of SWL on stone fragmentation of artificial and natural stones also revealed similar trends with the exception of artificial cystine stones which were found to be the most resistant to shock wave fragmentation.nnnCONCLUSIONSnThe results indicate that the physical properties of artificial stones made of natural stone materials are comparable to renal calculi of the same chemical composition. The data suggests that these stone phantoms are suitable for performing standardized and reproducible in vitro investigations, especially with regards to fragility of kidney stones of different chemical compositions during SWL.

In vivo assessment of free radical activity during shock wave lithotripsy using a microdialysis system: The renoprotective action of allopurinol

PURPOSEnShock wave lithotripsy is believed to cause renal damage directly through cellular injury from high energy shock waves and indirectly through vascular injury and resultant ischemia, which gives rise to oxygen free radical compounds. The transient and volatile nature of free radicals and derived products makes their detection difficult. Moreover, certain medications may provide a protective effect against shock wave lithotripsy induced renal parenchymal injury. We introduced an innovative microdialysis system for in vivo sampling of interstitial fluids that can be analyzed for free radical mediated lipid peroxidation products after shock wave lithotripsy treatment in the swine model. In addition, this system was used to test the antioxidant or renoprotective action of allopurinol.nnnMATERIALS AND METHODSnTen juvenile swine were assigned to a nonmedicated control group that underwent shock wave lithotripsy or to a group that was premedicated with allopurinol before shock wave lithotripsy. Each group of animals underwent shock wave lithotripsy to the lower pole of the right kidney and received a total of 10,000 shock waves. Dialysate fluid was collected at 1,000-shock wave increments via probes surgically implanted into the lower pole of the right and left kidneys before lithotripsy. Samples were immediately preserved in liquid nitrogen and subsequently analyzed for the presence and concentration of conjugated diene levels, a measure of lipid peroxidation. Five additional juvenile swine were assigned to a sham treated group that did not undergo shock wave lithotripsy. Dialysate fluid was collected from the lower pole of the right and left kidneys to establish baseline or pre-lithotripsy levels of conjugated dienes.nnnRESULTSnAfter shock wave lithotripsy conjugated diene levels increased almost 100-fold over that in the right kidneys of the nonmedicated control group. The difference was statistically significant compared to levels in the contralateral untreated kidneys (p <0.01). Right kidneys in the group premedicated with allopurinol did not demonstrate an increase in conjugated diene levels during shock wave lithotripsy.nnnCONCLUSIONSnThe results of this study confirm shock wave lithotripsy induced free radical activity as well the antioxidant and protective nature of allopurinol. The newly described microdialysis system enables real-time sampling of interstitial fluids during shock wave lithotripsy. It represents a unique method for assessing free radical formation and evaluating the protective effects of additional antioxidant medications.

Bilateral Renal Calculi: Assessment of Staged v Synchronous Percutaneous Nephrolithotomy

BACKGROUND AND PURPOSEnPercutaneous stone removal has replaced open renal surgery and has become the treatment of choice for large or complex renal calculi. However, patients with large bilateral stone burdens still present a challenge. Simultaneous bilateral percutaneous nephrolithotomy (PCNL) has been demonstrated to be a well-tolerated, safe, cost-effective, and expeditious treatment. We present what is, to our knowledge, the first large retrospective series comparing synchronous and asynchronous bilateral PCNL.nnnPATIENTS AND METHODSnA chart review was performed on 26 patients undergoing 57 PCNLs for bilateral renal calculi over a 7-year period. Seven patients received synchronous PCNL (same anesthesia; Group 1), and 19 patients underwent asynchronous PNL (procedures separated by 1-3 months; Group 2). Complete surgical and hospital records were available on all patients. The average stone burden for Group 1 was 8.03 cm(2) on the left and 9.18 cm(2) on the right v 10.1 cm(2) on the left and 14.23 cm(2) on the right for Group 2 (P> 0.05). Variables of interest included anesthesia time, operative time, blood loss, transfusion rates, length of hospital stay, and complication rates. Each variable was evaluated per operation and per renal unit. Follow-up imaging with stone assessment was available on 20 patients.nnnRESULTSnGroup 1 required 1.14 access tracts per renal unit to attempt complete clearance of the targeted stones v 1.88 tracts per renal unit in Group 2 (P> 0.05). The average operative time per renal unit was significantly less in Group 1 (83 minutes) than in Group 2 (168.5 minutes) (P< 0.0001), as was blood loss (178.5 mL v 307.4 mL, respectively; P= 0.02). However, blood loss per operation was similar at 357 mL in Group 1 and 282 mL in Group 2. Comparable transfusion rates of 28.6% and 36.8%, respectively, were noted. Forty percent of the patients in Group 1 were completely stone free compared with 36% of the patients in Group 2; however, an additional 50% and 57%, respectively, had residual stone burden <4 mm (P> 0.05). Complications occurred in 2 of 7 operations (28%) in Group 1 and 8 of 42 operations (19%) in Group 2. The total length of hospital stay was nearly doubled for patients undergoing staged PCNL (P= 0.0005).nnnCONCLUSIONSnThese results demonstrate similar stone-free rates, blood loss per operation, and transfusion rates for simultaneous and staged bilateral PCNL. The reduced total operative time, hospital stay, and total blood loss, along with the requirement for only one anesthesia, makes synchronous bilateral PCNL an attractive option for select individuals. However, in patients with larger, less easily accessible stones, excessive bleeding may be encountered more frequently on the first side, thereby delaying management of the second side to a later date. Synchronous bilateral PCNL should be considered in patients in whom the first stage of stone removal is accomplished quickly and safely.

Quality of life of men treated for localized prostate cancer: outcomes at 6 and 12 months

Goals of workTreatments for early-stage prostate cancer (PCa) are highly effective; therefore, research studies that explore quality of life (QOL) issues associated with different treatments are important. The purposes of this study were to (a) examine differences among treatment groups of men treated with either radiation therapies or radical prostatectomy for PCa and (b) examine quality of life outcomes over time.Patients and methodsWe report outcomes 6 and 12xa0months after 159 men began treatment for PCa with either one of two types of radiation treatment (intensity-modulated radiation therapy plus high dose rate or intensity-modulated radiation therapy plus seed implantation) or radical prostatectomy.Main resultsSignificant differences among groups are described. Significant predictors of QOL at 6xa0months included urinary, bowel, and sexual symptoms, anxiety, depression, problem-focused coping, and physiological self-efficacy. Significant predictors of QOL at 12xa0months were urinary and bowel symptoms, stress, depression, problem-focused coping, and physiological self-efficacy. Demographic variables, race, and living status were significant predictors of quality of life at 12xa0months.ConclusionsPhysiological symptoms and psychological symptoms were both significant predictors of QOL. The psychological factors that predicted quality of life in this study have potential for intervention and point to the next stage of the research.

Minimally invasive surgical management of pelvic‐ureteric junction obstruction: update on the current status of robotic‐assisted pyeloplasty

Pelvi‐ureteric junction (PUJ) obstruction is characterized by a functionally significant impairment of urinary transport caused by intrinsic or extrinsic obstruction in the area where the ureter joins the renal pelvis. The majority of cases are congenital in origin; however, acquired conditions at the level of the ureteropelvic junction may also present with symptoms and signs of obstruction. Historically, open pyeloplasty and endoscopic techniques have been the main surgical options with the intent of complete excision or incision of the obstruction. The advent of laparoscopy and robotic‐assisted applications has allowed for minimally invasive reconstructive surgery that mirrors open surgical techniques.

Prospective study of quality of life of patients receiving treatment for prostate cancer.

Background: No research was found that compared quality of life (QOL) outcomes of prostate cancer patients receiving intensity-modulated radiation therapies with prostate cancer patients receiving radical prostatectomy. Objectives: To (a) describe differences in QOL before and after three types of treatment for prostate cancer: radical prostatectomy, intensity-modulated radiation therapy + seed implantation (permanent brachytherapy), or intensity-modulated radiation therapy + high dose rate radiotherapy (temporary brachytherapy); and (b) investigate demographic, physical, and psychosocial variables that impact QOL of men with prostate cancer. Methods: Data were collected on three occasions: baseline (prior to treatment), 1 month, and 3 months after beginning treatment. Measures included biographic data, physiological, and psychological measures. Analysis of variance and hierarchical regression were used to examine patterns, describe differences, and identify predictors of QOL in the three treatment groups. QOL was conceptualized as a multidimensional construct that included physical, psychological, social, and functional well-being and prostate cancer concerns. Results: Groups differed significantly in bowel and urinary symptom scores and prostate cancer concerns at baseline, and in urinary and depressive symptoms at 3 months. There were no significant group differences at 1 month. Discussion: Significant differences were found in QOL as measured with the Functional Assessment of Cancer Treatment-Prostate after treatment with radical prostatectomy, intensity-modulated radiation therapy + seed implantation, or intensity-modulated radiation therapy + high dose rate radiotherapy. Findings may provide healthcare providers with knowledge about treatment sequelae for prostate cancer, enable healthcare providers to educate patients about QOL outcomes of treatment for prostate cancer, and enable patients to make more informed treatment decisions.