A two-dimensional numerical study of peristaltic contractions in obstructed ureter flows

The flow of urine from the kidneys to the bladder is accomplished via peristaltic contractions in the ureters. The peristalsis of urine through the ureter can sometimes be accompanied, more specifically, obstructed to a certain degree, by entities such as kidney stones. In this paper, 2D axisymmetric computational fluid dynamics simulations are carried out using the commercial code ANSYS FLUENT[Formula: see text], to model the peristaltic movement of the ureter with and without stone. The peristaltic movement was assumed to be a sinusoidal wave on the boundary of the ureter with a specific physiological velocity. While the first part of the study considers flow in the ureter with prescribed peristaltic contractions in absence of any obstruction, the second part compares the effect of varying obstructions (0, 5, 15, and 35%) in terms of spherical stones of different sizes. Pressure contours, velocity vectors, and profiles of pressure gradient magnitudes and wall shear stresses are presented along one bolus of the ureter, during contraction and expansion of the ureteral wall, in order to understand backflow, trapping and reflux phenomena, as well as monitor the health of the ureteral wall in the presence of any obstruction. The 35% ureteral obstruction case resulted in a significant backflow at the inlet in comparison to the other cases, and also a wall shear stress that was up to 20x larger than the case without any obstruction.

An interdisciplinary approach for surgical treatment of the renal mass

AIM

Recent trends in surgery for the renal mass indicate that the type of surgery performed may depend largely on surgeon practice style. Since 2004 we have used an interdisciplinary approach for the surgical treatment of the renal mass. We report the results of this practice including oncologic and surgical outcomes.

METHODS

A prospective database of patients undergoing treatment for renal mass was analyzed. Minimally invasive surgery (MIS) was performed by a laparoscopist, and open surgery was performed by a urologic oncologist. Demographic and clinicopathologic data were compared between treatment groups using nonparametric analysis of variance.

RESULTS

Of 120 patients treated for renal mass, 34% were treated after internal referral, 34% with nephron sparing surgery (NSS), 68% with MIS, and 32% with open surgery. Internal referrals accounted for 77% of patients who underwent open partial nephrectomy (OPN), 32% who underwent open radical nephrectomy (ORN), and 26% who underwent MIS. There were no significant differences in gender, mean ASA, or smoking history between groups. Patients in the ORN group were more likely symptomatic (P<0.001). Patients undergoing ORN or LRN had larger tumors than those undergoing open or laparoscopic partial nephrectomy (OPN and LPN) (P<0.001). Tumor stage, grade, and positive margin rate were highest in the ORN group (P<0.001). Hospital stay was shortest in the MIS and NSS groups (P<0.001). Complications were not different between groups.

CONCLUSION

An interdisciplinary approach to the treatment of renal mass involving both a laparoscopist and urologic oncologist may reduce the impact of surgeon practice style on the type of surgery performed.

Laparoscopic renal cryotherapy: biology, techniques and outcomes

AIM

The development of minimally invasive approaches to renal cell carcinoma (RCC) over the last 10 years has given rise to newer therapies such as renal cryotherapy. Patients with significant comorbidities who are not suitable for open surgery may be candidates for this procedure. Herein, we review the biology, techniques and outcomes of laparoscopic renal cryotherapy as performed at our institution.

METHODS

We present our initial experience with laparoscopic cryotherapy for the treatment of small, peripheral renal lesions and provide a review of the literature. A retrospective review was performed on our first 25 patients treated with transperitoneal laparoscopic cryotherapy for small peripheral renal lesions by a single surgeon between 2002 and 2003.

RESULTS

We treated 25 patients, average age of 65 years (range 32-83) with transperitoneal laparoscopic renal cryotherapy for small, enhancing, peripheral lesions suspicious for RCC. Mean pretreatment creatinine of 1.06 was unchanged after treatment. Mean tumor size was 2.4 cm (range 1.5-3.6 cm), with a mean EBL of 80 mL. Pathology revealed 72% RCC, 2 oncocytomas, one each arterio-nephrosclerosis, inflammatory tissue, focal-segmental glomerulosclerosis, angiomyolipoma and one normal tissue specimen. Average tumor grade was 2.3 (range 2-4). Mean hospital stay was 2.3 days (range 1-5). Three cases were converted to open. Two complications included transfusion and hydronephrosis, both managed conservatively. Mean follow-up is 16.2 months (range 6-36 months). There have been no recurrences to date despite a rigorous surveillance protocol.

CONCLUSIONS

Renal cryotherapy is a viable option for nephron sparing surgery in small, peripheral, renal lesions. The procedure is well tolerated, may be considered in patients who are not good candidates for open surgical approaches, results in minimal morbidity, and has very encouraging treatment results. Close surveillance post-treatment is essential. Longer follow-up data will be necessary to establish the durability of laparoscopic renal cryotherapy.

Radially expanding single-step nephrostomy tract dilator

OBJECTIVES

To compare the radial and axial forces produced by balloon, Amplatz, and radially expanding single-step nephrostomy (RESN) systems and report our initial clinical results using the new RESN device. Balloon, Amplatz, and Alken dilators are commonly used to establish nephrostomy tracts in percutaneous surgery. They require multiple steps, with the potential for kinking and displacement of the working guidewire. In contrast, the new RESN tract dilator expands a unique sleeve conduit and places an Amplatz-like sheath in a single step with less dependence on a guidewire for dilation.

METHODS

An experimental model was designed using a perforated silicon disc with a 10F central opening to measure the axial force transmission as 30F balloon, Amplatz, and RESN systems were inserted through the silicon discs. We also report our first 9 patients who underwent percutaneous dilation with the RESN system.

RESULTS

Thirty French expansion was achieved with each dilator tested. Substantially lower axial forces were transmitted with the RESN device compared with the balloon and Amplatz dilators (5.2 versus 13.1 and 19.2 lb, respectively, P <0.001). Intraoperatively, all 9 patients were successfully dilated, and the kidney was relatively stationary as imaged with fluoroscopy. One patient with multiple prior renal procedures was successfully dilated with RESN system after failed attempts with balloon dilation.

CONCLUSIONS

The RESN dilator is a rapid, single-step access system successfully used in our first 9 patients. Intraluminal sleeve dilation eliminates guidewire dependence for maintaining access, limits renal displacement, and facilitates appropriate vector force for percutaneous dilation.

Treatment of refractory kidney transplant ureteral strictures using balloon cautery endoureterotomy

OBJECTIVES

To report our long-term clinical results with the use of endoureterotomy in patients undergoing renal transplant with a minimum follow-up of 23 months.

METHODS

Six renal transplant patients developed persistent ureteral obstruction demonstrated by elevated serum creatinine levels, renal ultrasound, and antegrade pyelography. Stent placement and balloon dilation were performed as the initial therapy in all patients. Persistent ureteral obstruction was managed with balloon cautery endoureterotomy. Ureteral stents were removed cystoscopically 6 weeks after the procedure.

RESULTS

Four men and 2 women, mean age 45 years (range 38 to 54), underwent eight procedures: six by way of an antegrade percutaneous approach and two in an endoscopic retrograde fashion. The sites of ureteral stricture were ureterovesical junction (n = 4), ureteropelvic junction (n = 1), and midureteroureteral (n = 1). Two patients required a second endoureterotomy 3 months after the first attempt. Patients were followed up for a mean of 27 months (range 23 to 34). The mean serum creatinine level for all patients at follow-up was 2.6 mg/dL (range 1.6 to 3.9), including a mean serum creatinine level of 1.8 mg/dL (range 1.6 to 1.9) for nonrejected kidneys and a mean of 3.4 mg/dL (range 2.5 to 3.9) in those found to have concurrent rejection. Overall, five (63%) of eight procedures were successful in 5 (83%) of 6 patients. No intraoperative complications occurred and no blood transfusions were required.

CONCLUSIONS

Balloon cautery endoureterotomy was successful in this select group of renal transplant patients with persistent ureteral strictures after initial balloon dilation and stenting failed. This modality proved durable to 27 months of follow-up without significant complications.

Rethinking the role of urinary magnesium in calcium urolithiasis

BACKGROUND AND PURPOSE

The role of magnesium in urinary stone formation remains undefined. In vivo, magnesium inhibits stone formation in hyperoxaluric rats, and small clinical studies suggest a protective effect of magnesium supplementation in calcium oxalate stone formers. We performed a retrospective review of more than 7,000 stone patients to see if there is a relation between urinary magnesium and other stone risk variable constituents.

MATERIALS AND METHODS

A national database of stone formers categorized by residential ZIP code was queried, and, using strict inclusion criteria, 2,147 patients having pure calcium oxalate stones were identified. There were 1,912 (89%) eumagnesuric (43-246 mg/24 hours) and 235 (11%) hypomagnesuric (<43 mg/24 hours) patients.

RESULTS

Patients with decreased urinary magnesium excretion had significantly less daily urine excretion of citrate, calcium, oxalate, uric acid, and sodium than the eumagnesuric group (p < 0.0001). Stone recurrence was slightly more common in the hypomagnesuric group, although the difference was not statistically significant. The percentage of patients voiding <1 L of urine per day was significantly higher in the hypomagnesuric group. In the eumagnesuric group, males outnumbered females 2:1, whereas hypomagnesuric patients showed a female predominance of 1.4:1.

CONCLUSION

The beneficial effects of urinary magnesium on stone formation may be less than previously reported. The role of oral magnesium supplementation and the subsequent increase in urinary magnesium in calcium urinary stone formation remains unknown. Our data suggest that its effect on or interaction with citrate may be influential on urinary citrate concentrations. If magnesium has a protective effect, it may work through pathways that enhance citrate excretion.

Gahat: a Napalese cure for urolithiasis?

OBJECTIVES

Gahat (Vigna unguiculata) is a legume used for centuries in Nepal and Pakistan to treat the symptoms associated with urinary calculi. We prospectively evaluated the effect of Gahat consumption on 24-hour urine parameters in an attempt to assess its in vivo effect in normal volunteers.

METHODS

Eight non-stone-forming volunteers collected 24-hour urine specimens while on their routine diets for baseline data. Urine was analyzed for pH, volume, calcium, citrate, phosphate, sodium, magnesium, uric acid, and oxalate. The Gahat was prepared according to local custom. No additives were used to enhance flavor. The pureed mixture (8 ounces) was ingested three times daily for 2 days. Subjects were instructed to maintain their normal diet, including fluid intake and activity during the study period. Twenty-four hours after the start of Gahat intake, a second 24-hour urine collection was initiated while volunteers continued the Gahat. Results of the urine samples before and after Gahat intake were analyzed, using the paired Student t test.

RESULTS

There were no significant differences in urinary electrolytes between the urine samples before and after Gahat intake. Magnesium, urine volume, and uric acid differences approached clinical significance.

CONCLUSIONS

Gahat increased urinary magnesium through an unknown mechanism and had no effect on other routine 24-hour urine electrolytes. The increase in urinary volume is attributed to the increase in fluid consumption by the subjects. If this legume is effective in preventing or dissolving urinary calculi, it may act through mechanisms not identified in 24-hour urine electrolytes.

Diagnosis of prostate adenocarcinoma using transurethral resection of the prostate after multiple negative transrectal biopsies and persistently elevated prostate-specific antigen level

We report a case of prostate cancer diagnosis by transurethral resection of the prostate in a man who underwent more than 50 needle biopsies by three different physicians for an increasing prostate-specific antigen level. Radical prostatectomy resulted in removal of an organ-confined tumor (T2aN0M0), and a short follow-up revealed an undetectable prostate-specific antigen level.

Percutaneous management of caliceal diverticula

The diagnosis of a caliceal diverticulum may be serendipitous or established owing to patient symptoms. Once the decision to treat a diverticulum has been made, a percutaneous approach should be considered. If stones are present, complete stone removal and obliteration of the diverticulum should be the goals of surgery. The authors prefer the direct puncture technique whenever possible to limit the risk for bleeding and to facilitate stone removal. Use of a percutaneous approach in properly selected patients affords high success rates and results in few complications.

Endourologic management of urinary fistulae

PURPOSE

Historically, aggressive surgical exploration of renal fistulae has been associated with a 20% nephrectomy rate. We evaluated the role of minimally invasive techniques in the management of urinary fistulae.

MATERIALS AND METHODS

A retrospective review identified 10 renal fistulae in nine patients. Six renal-cutaneous, two renal-colonic, and two renal-pleural fistulae were referred for evaluation and treatment.

RESULTS

Five men and four women (mean age 54 years, range 32-76) were referred to the University of California, San Francisco Urinary Stone Center from 1988 to 1996. Of the six renal-cutaneous fistulae, four were spontaneous and two were iatrogenic. The iatrogenic fistulae occurred after an open pyelolithotomy (1) and a renal exploration performed after extracorporeal shock wave lithotripsy (1). The spontaneous fistulae resulted from obstructing calyceal calculi (2), infundibular stenosis (1), and obstructed nephrostomy tube (1). The two renal-colonic fistulae resulted from percutaneous nephrolithotomies, and the two renal-pleural fistulae developed after renal surgery. Eight of 10 fistulae resolved with minimally invasive endoscopic techniques and relief of urinary obstruction. One nephrectomy was performed for a small nonfunctioning kidney after failed open pyelolithotomy. One patient refused all treatment and the fistula resolved spontaneously.

CONCLUSIONS

Conservative management of both spontaneous and iatrogenic renal fistulae is possible by relieving urinary obstruction and using minimally invasive endoscopic techniques. Low nephrectomy rates can be expected using these methods.

Impact of body weight on urinary electrolytes in urinary stone formers

OBJECTIVES

Obesity increases the risk of developing chronic medical conditions such as diabetes mellitus, hypertension, and coronary artery disease. We performed a retrospective review of a large data base on urinary stones to determine if differences are found in urine and serum chemistries among obese and nonobese stone-forming patients. The effect of body weight on stone recurrence among urinary stone formers was also determined.

METHODS

A national data base containing serum biochemical profiles, 24-hour urine specimens, and standardized questionnaires was retrospectively evaluated from 5942 consecutive patients with urinary stone disease. Stone-forming patients were classified by body weight: nonobese men, less than 100 kg and nonobese women, less than 85 kg; intermediate men, 100 to 120 kg and intermediate women, 85 to 100 kg; and obese men, more than 120 kg and obese women, more than 100 kg.

RESULTS

Obese stone formers comprised 6.8% (n = 404) of the patient population. The mean weight in the nonobese and obese groups was 81 kg versus 134 kg, respectively, for men and 64 kg versus 112 kg, respectively, for women. Obese patients represented 3.8% of the male and 12.6% of the female population. Obese patients had increased urinary excretion of sodium, calcium, magnesium, citrate, sulfate, phosphate, oxalate, uric acid, and cystine; obesity was associated with increased urinary volumes and urine osmolality compared with the nonobese patients. Obese men had increased concentration of urinary sodium, oxalate, uric acid, sulfate, and phosphate when corrected for urinary volume. Obese women had increased concentrations of sodium, uric acid, sulfate, phosphate, and cystine. The mean number of stone episodes in nonobese versus obese men was similar (3.55 and 3.56), whereas mean stone episodes were 2.93 and 3.38 (P = 0.045) for nonobese versus obese women.

CONCLUSIONS

Among known stone formers, obesity is associated with unique changes in both serum and urinary chemistries. These changes are associated with an increased incidence of urinary stone episodes in obese women but not in obese men.

The vesical calculus

Bladder calculi account for 5% of urinary calculi and usually occur because of foreign bodies, obstruction, or infection. Males with prostate disease or previous prostate surgery and women who undergo anti-incontinence surgery are at higher risk for developing bladder calculi. Patients with SCI with indwelling Foley catheters are at high risk for developing stones. There appears to be a significant association between bladder calculi and the formation of malignant bladder tumors in these patients. Transplant recipients are not at increased risk for developing vesical calculi in the absence of intravesical suture fragments and other foreign bodies. Patients who undergo bladder-augmentation procedures using a vascularized gastric patch appear to be protected from vesicolithiasis, perhaps by the acidic environment. Ileum and colon tissues, however, are colonized by urease-producing organisms, producing an alkaline pH that promotes stone formation. Children remain at high risk for bladder-stone development in endemic areas. Diet, voiding dysfunction, and uncorrected anatomic abnormalities, such as posterior urethral valves and vesicoureteral reflux, predispose them to bladder-calculus formation. Finally, there are a number of techniques and modalities available to remove bladder stones. Relieving obstruction, eliminating infection, meticulous surgical technique, and accurate diagnosis are essential in their treatment.

An in vitro assessment of the flow characteristics of spiral-ridged and smooth-walled JJ ureteric stents

OBJECTIVE

To assess drainage through spiral-ridged and smooth-walled JJ ureteric stents (designed to ensure upper tract drainage) and thus determine whether drainage preferentially occurs around rather than through the spiral-ridged stent, promoting renal flow and potentially facilitating the passage of urinary stone fragments. Materials and methods A mechanical ureteric model was constructed to mimic the funnel characteristics of the renal pelvis. A motor pump was used to help simulate respiratory and skeletal movement, resulting in differential motion between the intraluminal stent and the surrounding ureteric wall. Tubes of varying internal diameters were used to simulate different sizes of ureter. Flow rates of standard 7 F smooth-walled stents were compared with 7 F spiral-ridged stents with and without occluded lumens, and with and without standardized excursions.

RESULTS

Extraluminal flow (mean rates) with and without movements simulating respiratory excursions were significantly higher with the spiral stent for all stent diameters evaluated. All flow rates increased as the ureteric diameter increased. Total flow past the spiral stent was significantly greater than flow with the smooth-walled stent under all conditions tested. Flows measured around the spiral stent under conditions of excursion were the highest of all categories, 20-fold higher than in smooth-walled, closed, stationary stents.

CONCLUSION

Spiral-ridged JJ stents provided substantially greater flow in this in vitro model. Extraluminal flow was markedly increased with the spiral-ridged configuration. The difference in flow rates was more pronounced at the smaller pseudo-ureteric tube diameters, simulating dimensions found in clinical practice. The flow rate also was increased when the central lumen remained open, and was greater still when there was dynamic excursion with respiratory movements.

Gross hematuria secondary to renal vein hypertension from unilateral retroperitoneal fibrosis

We report the first case of localized, unilateral, idiopathic retroperitoneal fibrosis encasing the left renal vein, which resulted in secondary renal vein hypertension. The patient presented with sudden and dramatic gross hematuria. Surgical release and excision of the surrounding localized retroperitoneal fibrosis resulted in prompt resolution of the hematuria.

Complications of retrograde balloon cautery endopyelotomy

PURPOSE

Adult ureteropelvic junction obstruction is increasingly managed with endoscopic techniques. Retrograde balloon cautery endopyelotomy is quick, requires minimal hospital stay and allows most patients a rapid return to work. The complication rate of retrograde balloon cautery endopyelotomy ranges from 13 to 34%, with vascular injury in 0 to 16% of patients. We report 5 uncommon complications, including 4 vascular injuries, that clinicians should be familiar with when using this technique.

MATERIALS AND METHODS

We reviewed 52 retrograde endoscopic endopyelotomy procedures performed during a 5-year period. There were 5 uncommon complications.

RESULTS

Accessory lower pole renal artery injuries occurred in 3 patients, 1 of whom presented 12 days after endopyelotomy. Embolization was successfully performed in all 3 cases and none had subsequent hypertension. In 1 case a right ovarian vein laceration was not evident on preoperative or postoperative angiography. Emergency post-embolization abdominal exploration revealed a 2 mm. injury to the right ovarian vein before entering the right renal vein close to the ureteropelvic junction incision. Nephrectomy and ovarian vein ligature were curative. In 1 case the electrocautery wire broke intracorporeally after firing, resulting in a bobby pin-like configuration. Successful removal was accomplished by twisting the catheter and wrapping the wire around the tip, enabling atraumatic removal.

CONCLUSIONS

Retrograde balloon cautery endopyelotomy is an emerging technology with potential adverse outcomes. The complications we noted are complex and potentially life threatening. Awareness of these complications may help avoid poor outcomes and expedite appropriate treatment.

Nonsurgical management of infection-related renal calculi

Struvite calculi can be a debilitating affliction for which the cure is mainly surgical. If left untreated, infection-related calculi can cause failure to thrive, anemia, chronic renal insufficiency, renal failure and death. There has been much research aimed at non-surgical intervention and prevention of these calculi especially in this "non-invasive" era. The historic and current non-surgical treatment modalities of struvite calculi are discussed.

Autologous blood use in percutaneous nephrolithotomy

OBJECTIVES

Preoperative autologous blood (AUB) donation has decreased patient exposure to allogenic blood (ALB) products and associated infectious risk. The risk of contracting hepatitis C and human immunodeficiency virus is 1 in 103,000 and 1 in 678,000, respectively, after receiving 1 U ALB. Elective surgical procedures require surgeons to offer preoperative AUB donation in California. Unused AUB is discarded. We report our use of AUB obtained for percutaneous nephrolithotomy.

METHODS

A retrospective study of 144 consecutive patients who underwent 193 percutaneous nephrolithotomies between January 1994 and April 1998 at one of four teaching hospitals at the University of California, San Francisco was performed. Preoperative AUB donation, transfusion rates, hemoglobin levels, blood use, and costs were analyzed.

RESULTS

Ninety-six units of blood were collected from 63 patients (44%) and were available for 70 procedures (36%). The overall transfusion rate per procedure was 7%, with 13 patients receiving a total of 24 U, 7 AUB and 17 ALB. Eighty-nine units (92.7%) of AUB were discarded, and the transfusion rate in donors and nondonors was similar. There was no significant difference in preoperative hemoglobin or operative blood loss between donors and nondonors. The 13 transfused patients had a lower preoperative hemoglobin ( 11.5 versus 12.8 g/dL; P = 0.029) and higher operative blood loss as measured by hemoglobin level (3.2 versus 1.6 g/dL; P <0.001). Blood bank charges for ALB and AUB were $ 119/U and $244 to $498/U, respectively, depending on transportation and thawing charges.

CONCLUSIONS

Routine preoperative blood donation adds substantial cost for minimal benefit, given the low infectious risk of ALB and the two- to fourfold higher cost of AUB. In our series, women had an increased incidence of blood transfusion compared with men. AUB donation may provide peace of mind but is rarely used and is discarded 93% of the time.

The effect of colonoscopy on serum prostate specific antigen levels

OBJECTIVE

To evaluate, in a prospective trial, the effect of colonoscopy on serum prostate specific antigen (PSA) levels (which are known to increase after cystoscopy and prostatic needle biopsy) in men aged 50-70 years, as they commonly undergo colonoscopy and PSA screening together.

SUBJECTS AND METHODS

Twenty-four consecutive men (mean age 61 years, range 37-78) were enrolled in the study. All subjects had their serum PSA measured 24-72 h before undergoing colonoscopy. Further values were obtained 24 h, 7 and 30 days after the procedure. The values before and after colonoscopy were compared to evaluate the effect of colonoscopy on serum PSA levels.

RESULTS

Of 24 patients, seven (35%) had insignificant increases at 24 h after colonoscopy; 12 (50%) patients had an insignificant increase in PSA level 30 days after the procedure. None of the 24 patients had a significant increase after colonoscopy when compared with baseline values.

CONCLUSION

Flexible colonoscopy does not adversely affect serum PSA levels. Although individuals may have a 30% daily fluctuation in serum values, this study detected no significant change in serum PSA levels after prolonged transrectal prostatic manipulation with a colonoscope.

Historical perspectives and current advancements in the bacteriology and medical therapy of struvite urinary stone disease

Struvite calculi have afflicted man for thousands of years. Despite recent advances in surgical technology to treat these disabling stones, high recurrence rates and inability to remove all stone fragments remain significant problems. Previous non-surgical alternatives have been disappointing because of low success rates, increased side effects or poor tolerability. New research in this area continues to provide insight into origins of lithogenesis and non-invasive therapy for calculi caused by infection.

Imaging characteristics of indinavir calculi

PURPOSE

Indinavir sulfate is an effective protease inhibitor of the human immunodeficiency virus type 1. Use is associated with a significant incidence of crystallization and stone formation in the urinary tract, and these calculi are not visible on plain radiographs. Previously all urinary stones, including uric acid and matrix, were believed to be radiodense on computerized tomography (CT). We conducted a retrospective study to evaluate the radiographic appearance of indinavir calculi.

MATERIALS AND METHODS

Retrospective chart review of 36 patients taking indinavir sulfate and presenting with renal colic was performed with attention to presentation, urinalysis, radiographic evaluation and management. Specifically, imaging characteristics on CT were addressed.

RESULTS

All patients complained of ipsilateral flank pain and 35 had nausea and/or vomiting. Of 30 patients with dysuria or urgency the majority had hematuria, and most had pyuria and/or proteinuria. No stones were visualized on abdominal radiography. Diagnosis was confirmed on 1 of 13 excretory urograms and 4 of 11 renal ultrasounds. None of 12 CT scans was diagnostic of renal lithiasis.

CONCLUSIONS

Indinavir sulfate is a protease inhibitor with poor solubility and significant urinary excretion. Crystallization and stone formation are demonstrated in as many as 20% of patients taking the medication. Most patients present with flank pain, nausea or vomiting and hematuria. Previously CT was thought to identify all urinary calculi with clarity but it cannot reliably confirm the presence of indinavir calculi.

Percutaneous access techniques in renal surgery

Percutaneous renal surgery is continually being improved, refined, and embraced by urologists worldwide. With the advent of extracorporeal shock wave lithotripsy (ESWL), many percutaneous techniques have been abandoned or forgotten. We are learning, however, that ESWL is not a panacea for all urinary calculi and different methods need to be used to obtain stone-free patients. We discuss the history, anatomy, techniques, and specific problems and complications ofpercutaneous renal surgery specifically relating to renal stone disease.

Urethral calculus extraction using a penile ring block anesthetic

Urethral calculi are rare and usually originate from the kidney or bladder. Classically, they are extracted endoscopically under anesthesia. We present two cases of impacted distal urethral calculi extracted using a penile ring block and forceps.

Home flow rates in evaluation of lower urinary tract symptoms in men

We wanted to determine if 5-second home flow rates can be used in the evaluation in men with lower urinary tract symptoms (LUTS). Fifty previously untreated men with LUTS were evaluated by history and physical examination, international prostate symptom score (IPSS) questionnaire, and two methods of uroflowmetry. Each participant underwent three formal uroflow measurements using the Dantec UD5500 Mk2 machine and subjective 5-second home uroflow measurements twice daily for 7 days. The reliability of each test as well as correlation coefficients between the two methods of uroflowmetry were determined. The reliability for the average of the 14 home flow rates was 0.99 and the reliability for any single home flow was 0.82. Reliability for the average of three uroflows in measuring Qmax, Qave, flow times, and volume are 0.91, 0.91, 0.86, and 0.79, respectively. If single measurements are used, the values are 0.77, 0.78, 0.68, and 0.56. Home flow average is significantly different from Qmax and Qave (p < .001). No significant correlation was found between any of the uroflowmetry measurements or home flow average and IPSS or bother score. Home flows rates and uroflowmetry are reliable tests. There is a weak correlation between average home flows and Qmax and Qave. The greatest use of home flow rates probably lies in follow-up of patients who had either medical or surgical intervention for LUTS.

The use of an external vacuum device to augment a penile prosthesis

Although penile prostheses are highly effective in the treatment of erectile dysfunction, a small percentage of patients are dissatisfied. Serendipitously, a patient in this group found that using an external vacuum device to augment his prosthetic erection provided a dramatic objective improvement in his erection and increased his overall satisfaction with intercourse. Patients who had tried the combination of external vacuum device and penile prosthesis simultaneously were identified from our penile prosthesis population as well as the Osbon Medical Systems database. Telephone interviews were conducted to determine efficacy, satisfaction, and side effects from the combination. Twelve patients completed the telephone survey. Four patients had semirigid and eight had inflatable penile prostheses. After using the vacuum device to augment the erection, all reported increased rigidity and patient/partner satisfaction, and 11 of 12 described improved length and girth. Minimal complications were noted. Concomitant use of an external vacuum device and penile prosthesis was safe in this select population. The combination may be indicated in patients with penile prostheses who are dissatisfied with size and/or rigidity, and in those who refuse or who are poor candidates for prosthesis revision.

A randomized prospective comparison of antibiotic tissue levels in the corpora cavernosa of patients undergoing penile prosthesis implantation using gentamicin plus cefazolin versus an oral fluoroquinolone for prophylaxis

PURPOSE

We performed a prospective randomized trial comparing the efficacy, safety and cost of parenteral antibiotics and oral fluoroquinolones for prophylaxis in penile prosthesis surgery.

MATERIALS AND METHODS

We prospectively randomized 20 consecutive patients undergoing penile prosthesis surgery to receive ofloxacin orally or gentamicin and cefazolin parenterally followed by cephradine orally. Intraoperatively corpora cavernosa tissue and simultaneous peripheral serum samples were evaluated for antibiotic levels. Median followup was 16 months (range 8 to 21, mean 15.35).

RESULTS

There were no implant losses or reoperations and complications were comparable in the 2 groups. The difference in mean serum-to-tissue ratios of ofloxacin versus the combination of cefazolin and gentamicin was statistically significant (p < 0.03). The minimum inhibitory concentrations of ofloxacin met or exceeded those of the 2 most common offending organisms, Staphylococcus epidermidis and Escherichia coli, in 80% of patients, which was comparable to the results of the parenteral regimen. Cost savings of the medications alone were more than $250,000 in the ofloxacin group. By eliminating a hospital stay of the 25,000 cases of penile prosthesis placement in the United States yearly a total cost savings of more than $36 million would be realized.

CONCLUSIONS

When oral ofloxacin is given for prophylaxis in penile implant surgery, the procedure may be performed on an outpatient basis and health care dollars are saved.

Prognostic value of BHCG and local tumor invasion in stage I seminoma of the testis

Approximately 10-15% of patients with stage 1 pure seminoma of the testis have an elevated preorchiectomy serum beta human chorionic gonadotropin level [1-4]. The prognostic significance of this elevation is unknown. We performed a multi-institutional retrospective review of 332 men with stage I pure seminoma of the testis and evaluated the prognostic significance of this elevation and the prognostic value of local invasion of the primary tumor. Twenty-five of 191 evaluable patients (13%) had elevated preorchiectomy beta human chorionic gonadotropin. All normalized postoperatively and are alive without evidence of disease with a median follow-up of 50 months (range 1-124 mo). Of 191 patients, 190 (99.5%) are alive and free of disease. One patient underwent salvage chemotherapy for a chest recurrence, and he is alive and free of disease at 72 months. We conclude that elevated preorchiectomy serum beta human chorionic gonadotropin level and local invasion of the primary tumor do not portend a poor prognosis in patients with clinical stage I pure seminoma of the testis.

The role of cystoscopy before radical prostatectomy

OBJECTIVE

To determine the role of pre-operative cystoscopy in men undergoing radical prostatectomy for clinically localized adenocarcinoma of the prostate.

PATIENTS AND METHODS

One hundred men undergoing radical prostatectomy for clinically localized adenocarcinoma of the prostate were evaluated for coexisting bladder pathology from a retrospective review of their charts and records.

RESULTS

Four of 100 men undergoing radical prostatectomy for clinically localized prostate cancer were found to have synchronous bladder tumours. Two of these had superficial low-grade transitional cell carcinoma (TCC), one had a poorly differentiated invasive TCC and the last was found to have an inverted papilloma during radical retropubic prostatectomy. The patient with invasive disease died before the initiation of definitive therapy. The other three men are free of disease 2 years after diagnosis and treatment.

CONCLUSION

Because of the low cost and minimal morbidity of pre-operative flexible cystoscopy, we recommend that this procedure be performed on the operating table before prostatectomy. In patients with gross or microscopic haematuria, a significant history of smoking, a prior history of urothelial malignancy or symptoms of bladder outlet obstruction, cystoscopy would be best performed before surgery in an out-patient setting.

Diagnosis of fetal anterior abdominal wall defects by use of ultrasonography

Omphalocele and gastroschisis involve protrusion of intestine through a defect in the abdominal wall. It is important to differentiate between the two because of a difference in the incidence of associated anomalies and of chromosomal abnormalities. The distinguishing characteristics are the location of umbilical cord insertion, the echogenicity of the contents of the protruding mass and, usually, the presence or absence of a sac surrounding the mass. Early detection is critical so that decisions can be made about the possibility of surgical correction and the outcome of the pregnancy. We describe an omphalocele detected by ultrasonography in the 20th week of gestation during a routine prenatal check-up.