The pathophysiology of ureteral obstruction

Ureteral obstruction can have a variety of causes intrinsic or extrinsic to the kidney. The effects of obstruction are examined from the perspectives of duration, severity, totality, and the presence of complicating factors. There is a difference in the postobstructive pathophysiology depending on whether one or both ureters were obstructed. Atrial natriuretic peptide may be important in postobstructive diuresis, and preliminary evidence suggests a role for it as protection against nephron ischemia in acute obstruction. The potential for recovery of renal function after relief of obstruction depends on the duration and degree of obstruction, the condition of the contralateral kidney, and the presence or absence of infection. Ability to acidify the urine to pH < 6.0 preoperatively may be a good predictor of the recovery potential of an obstructed kidney. Urine concentrations of lysosomal enzymes such as N-acetylglucosaminidase also may be useful for this purpose, as may measurement of creatinine clearance in urine obtained from a nephrostomy tube.

Stent use with extracorporeal shock wave lithotripsy

Since the advantages of using ureteral stents in conjunction with extracorporeal shock wave lithotripsy were first recognized, the growing demand for outpatient stone treatment has made stent use much more frequent. However, prophylactic stent placement must be judicious to maximize success and minimize associated morbidity. Recent controlled retrospective studies and randomized trials showed that ureteral stenting does not increase the stone-free rate or reduce the complication rate for stones less than 2 cm in size, yet in such cases, there are increased morbidities such as urinary urgency, frequency, stent migration, and encrustation. However, in patients with stones larger than 2 cm, Type C4 staghorn calculi, or stones associated with a solitary kidney, prophylactic stent placement may reduce the complication rates arising from these larger stone burdens. Finally, ureteral stenting may be helpful for stone localization or manipulation.

Identifying risk factors in development of clinically significant post-shock-wave lithotripsy subcapsular hematomas

A retrospective study of 1,012 shock-wave lithotripsy treatments was performed to identify and analyze the risk factors for the development of six clinically significant post-extracorporeal shock-wave lithotripsy (ESWL) subcapsular hematomas. The patients studied had clinical signs and symptoms that on evaluation were confirmed as originating from a subcapsular hematoma. Common factors identified which we believe may put patients at increased risk for the development of subcapsular hematoma included hypertension, diabetes mellitus, coronary artery disease, and obesity.

The recovery of Mycobacterium avium complex and Mycobacterium tuberculosis from blood specimens of AIDS patients using the nonradiometric BACTEC NR 660 medium

The ability of the nonradiometric BACTEC NR 660 aerobic 6A blood culture medium to support mycobacterial growth was investigated. During a 19-month period blood cultures from 140 AIDS patients were sent to the microbiology laboratory. After the cultures were incubated for seven days, aliquots of medium from the vials were centrifuged, sediments examined microscopically for mycobacteria, and cultured to mycobacterial media. Seventy-one AIDS patients (51%) had at least one blood culture positive for mycobacteria. There was a significant difference in the percent of female AIDS patients positive for mycobacteria compared to male patients (72% vs. 44%, P less than 0.01). Forty-four percent of all subsequently positive cultures were detected by an acid fast stain of the specimen sediment. Subcultures from the BACTEC 6A suspensions were positive on mycobacterial media at one-seven weeks (mean three weeks) after planting. Sixty-nine of the isolates were Mycobacterium avium complex, while two were Mycobacterium tuberculosis. Some bacteremias with M. tuberculosis may have been undetected because growth experiments with a reference strain showed that, in contrast to M. avium complex, M. tuberculosis did not increase in concentration in 6A medium.

Additional evidence for lack of transmission of HIV infection by close interpersonal (casual) contact

To further study the possibility of transmission of HIV infection by close personal but non-sexual, non-parenteral contact we have continued to enroll and evaluate household contacts of adult patients with AIDS. Two hundred and six household contacts of 90 patients with AIDS were evaluated with detailed interviews, physical examinations, and detection of HIV antibodies and p24 antigen from 1984 to 1987; 118 of these contacts were re-evaluated 6-12 months after cessation of household contact or death of the patient. The median duration of household contact from 18 months prior to symptoms in the AIDS patients to last contact was 23 months (range 3-101 months). The median time elapsed from first contact during this period to the last evaluation was 38 months (range 13-66 months). No household contact had signs or symptoms suggesting HIV infection. All 206 were negative for serum antibodies to HIV and HIV p24 antigen, despite extensive sharing of household facilities and items and personal interactions with AIDS patients. This study continues to show that household members without other risks remain at minimal to no risk for HIV transmission (95% confidence interval, 0-1.44) despite prolonged and substantial close non-sexual contact with AIDS patients, and after re-evaluation at a median of 10.9 months after initial evaluation.

Aspirin-induced bilateral renal hemorrhage after extracorporeal shock wave lithotripsy therapy: implications and conclusions

We report a case of bilateral intrarenal, subcapsular and perirenal hematomas after extracorporeal shock wave lithotripsy. Following treatment chest pain developed necessitating monitoring in the intensive care unit and cardiac evaluation. Serial hematocrit levels during the next 2 days revealed a decrease from 48 to 23%, requiring multiple transfusions. After therapy it was recognized that the patient had taken aspirin on a daily basis within 1 week before lithotripsy. We postulate that the aspirin ingestions acted as a potential predisposing factor in the formation of the bilateral renal hematoma.

Comparison of extracorporeal shock-wave lithotripsy and surgical lithotomy regarding patient satisfaction

A series of 19 patients who underwent extracorporeal shock-wave lithotripsy (ESWL) for urolithiasis was compared with 26 patients who were treated with surgical lithotomy (SL). A historical clinical trial was conducted using hospital chart records and telephone interviews to determine differences in outcome between the two groups. The ESWL group had significantly (p less than 0.05) shorter duration of post-procedural pain, fewer requirements for pain medications, and decreased anxiety toward repetition of the procedure than did the SL group. In addition, the ESWL group had significantly (p less than 0.05) shorter hospital stays, faster return to work on discharge from the hospital, and less physical limitation after the procedure. There was no appreciable difference in the occurrence of post-procedure urinary tract infections or in the patient's perception of the effectiveness of the procedure. These findings support the conclusion that treatment of urolithiasis by ESWL, is preferable to open flank SL.

Extracorporeal shock wave lithotripsy treatment of spinal cord injury patients

A total of 32 male patients with spinal cord injury underwent extracorporeal shock wave lithotripsy. The mean stone burden was 2.9 cm. (range 0.2 to 8.0 cm.) per renal unit. Of 41 renal units 27 (66 per cent) required ancillary endourological procedures preoperatively and 32 (78 per cent) required a single treatment with extracorporeal shock wave lithotripsy. Urine cultures were positive in 30 of 32 patients (94 per cent) before treatment. All patients with positive preextracorporeal shock wave lithotripsy urine cultures also had positive cultures after treatment. Followup (3-month) was available for 26 of 41 renal units (63 per cent) and showed 19 (73 per cent) to be free of stones or without any radiographic evidence of calcification overlying the collecting system. Seven staghorn calculi were treated with extracorporeal shock wave lithotripsy without prior debulking procedures. Two partial staghorn calculi were treated and rendered free of stones. None of the 5 kidneys with full staghorn calculi was rendered free of stones. We conclude that extracorporeal shock wave lithotripsy is effective for the treatment of unbranched and partial staghorn calculi in the spinal cord injury patient. However, extracorporeal shock wave lithotripsy alone is less effective for the treatment of full staghorn calculi.

Ureteral stents. Indications, variations, and complications

Indwelling ureteral stents offer the urologist an enormous arsenal against a host of urologic diseases. No stent is ideal, and as such it is incumbent on the surgeon to be familiar with the various indications for usage, selection, modes of insertion, and potential for complications. With such information, the surgeon will optimize the efficacy and safety of this device in the care of patients.

Renal pelvic pressures during extracorporeal shock-wave lithotripsy

Renal pelvic pressures were studied in 4 patients with indwelling nephrostomy tubes undergoing extracorporeal shock-wave lithotripsy (ESWL). The pressures were monitored by attaching the patients' nephrostomy tubes to an electrical pressure transducer. Three of these patients had ureteral stents placed to prevent outflow obstruction from disintegrated stone fragments. The mean pelvic pressure increased from 17.0 cm H2O at the start to 52 cm H2O at the conclusion of ESWL. Two hours post-ESWL, the pressures declined to a mean of 27.0 cm H2O. The maximum pelvic urine volume as determined by aspirating the nephrostomy tubes at the conclusion of the procedure was 6 cc. The observed rise in pelvic pressure may be explained by a sustained contraction of the pelvic smooth musculature.

Second-generation shock-wave lithotripters. Variations, indications, and efficacy in the treatment of ureteral calculi

Second-generation lithotripters offer significant advances in the technology and delivery of high-energy shock waves. The final position that ultrasonographically guided machines will earn in the spectrum of lithotripters can be determined only as more clinical series are reported. Nonetheless, their compromised ability to handle ureteral calculi casts a shadow on the acquisition of such instruments by facilities that cannot afford to own and operate both x-ray and sonographically guided lithotripters.

Biliary obstruction complicating extracorporeal shock wave lithotripsy

An elderly woman with a solitary right kidney and unrecognized cholelithiasis underwent extracorporeal shock wave lithotripsy for renal calculi. Postoperatively, biliary obstruction developed that required emergency surgery. Pathological evaluation of the biliary calculi revealed superficial fragmentation. It is suggested that extracorporeal shock wave lithotripsy was responsible for the gallstone fragmentation and resultant bile duct obstruction.

Measurement of renal pelvis pressures during endourologic procedures

Twenty-five kidneys underwent nephrostomy puncture with placement of a pigtail catheter into an upper pole calyx for manometric recording during nephroscopy without a working sheath and with an Amplatz sheath with and without a Rutner adapter. Intrarenal pressures remained below 16 cm of water (H2O) at all times with the Amplatz sheath with or without a Rutner adapter, whereas without a sheath the pressures ranged from 15 to 31 cm H2O (i.e., pressures associated with significant pyelovenous and pyelosinus backflow). Similar results were obtained in monitoring intrarenal pressures during clinical procedures. A working sheath should be utilized for all percutaneous nephroscopic procedures to minimize the incidence of pyelovenous and pyelosinus backflow as well as of perirenal extravasation of the irrigation solution. Even with a wide-lumen ureteral catheter in place, drainage via the ureter is not sufficient to maintain the intrapelvic pressure in the physiologic range.

Extragonadal retroperitoneal germ cell tumors without apparent testicular involvement. A search for the source

Extratesticular germ cell neoplasms without apparent testicular primary tumors are rare. The origin of these neoplasms has been debated in the literature for decades. With the advent of effective chemotherapy for extratesticular germ cell neoplasms, the origin of these tumors becomes more than academic. We report on 3 cases of retroperitoneal germ cell neoplasms with microscopic intratesticular primary tumors. All patients with extragonadal germinal cell tumors of the testes should undergo thorough investigation for an occult testicular primary tumor despite a normal testis examination. We review previously reported cases of extratesticular germ cell neoplasms without an apparent testicular primary tumor.

Exstrophy of bladder: evolution of management

Eighty-nine patients with bladder exstrophy were seen at our institution over the last fifty years. There were 63 males and 26 females. Cloacal exstrophy constituted 9 per cent of our experience. Twenty-seven patients underwent primary urinary diversion with subsequent genital reconstruction early on in our series. Of the 57 children operated on since 1951, 50 were judged eligible for and underwent a planned multistaged reconstruction. We realized a 50 per cent success rate. The majority of failures were diverted into an ileal conduit for persistent incontinence.