Biomedical subjects

R V Clayman

Publications and source records attributed to R V Clayman.

At least 109 records · Page 6Linked to original sources

PubMed1997

Effect of mineral oil on porcine urothelium.

Mineral oil has been used to facilitate ureteral stone extraction and to treat selected patients with infected residual urine. The purpose of this study was to evaluate the effect of mineral oil on the urothelium. Twelve adult female farm pigs underwent bilateral ureteral catheter placement under general endotracheal anesthesia. Retrograde pyelograms were performed and the ureteral diameters measured. Using a randomization protocol, six animals underwent injection of 10 mL of normal saline into one ureteral catheter and 50 mL of normal saline instillation into the bladder. In the remaining six animals, 10 mL of mineral oil was injected into one ureteral catheter and 50 mL of mineral oil into the bladder. The instillation was maintained for 30 minutes, and then the catheters were removed. One week later, under general endotracheal anesthesia, cystoscopy and retrograde pyelography were performed to measure the diameter of the ureters, and the animals were euthanized. The bladder, ureters, and kidneys were harvested for macroscopic and histopathologic evaluation. There was no significant difference in the diameter of the ureters injected with normal saline, the uninjected ureters, or the mineral oil-injected ureters. The bladders, ureters, and kidneys were grossly normal in all animals. No significant histopathologic changes were noted in the ureteral or bladder urothelium or the renal parenchyma in the animals injected with mineral oil. In conclusion, the instillation of mineral oil within the urinary tract does not have any significant long-term functional or histopathologic effect on the urothelium.

Animals↗

PubMed1997

In vivo comparison of electrosurgical vaporization electrodes.

To determine the acute tissue effects of endoscopic electrosurgery using different electrodes, smooth ball, smooth bar, vertically grooved bar, and horizontally fluted bar electrodes were applied to the epithelial surface of porcine bladders in vivo with electrosurgical cutting current supplied at 100, 150, and 200 W. A single pass was made on the surface of the tissue under endoscopic control with sorbitol irrigation using an excursion rate of 5 mm/sec. Each electrode was tested five times at each setting. The depths of electrosurgical vaporization and coagulation were measured by a pathologist blinded to the electrode and power setting. Depth of vaporization increased with the power setting of the generator and was greater with the non-smooth electrodes than the smooth electrodes. The depth of coagulation likewise was greater using the non-smooth electrodes but increased only minimally with increasing power settings. There were no differences in vaporization or coagulation depth between the small ball and smooth bar electrodes. The differences between the vertically grooved bar and horizontally fluted bar also were insignificant, except that in one-third of cases, the horizontally fluted bar created clefts undermining otherwise-undamaged areas of tissue. Non-smooth electrosurgical electrodes produce more vaporization and coagulation than smooth electrodes at a given power setting and therefore may be preferred for endoscopic applications. For use in tissues where precise control is required, the vertically grooved bar may be superior to the horizontally fluted bar because it provides similar vaporization and coagulation with a more uniform tissue effect.

Animals↗

PubMed1997

Long-term results of endoureterotomy for benign ureteral and ureteroenteric strictures.

PURPOSE: We reviewed the results of endoureterotomy for benign ureteral and ureteroenteric strictures to determine efficacy and factors associated with a successful outcome. MATERIALS AND METHODS: Followup was available for 69 patients undergoing 77 endoureterotomies. Success was defined as symptomatic improvement and radiographic resolution of obstruction. Kaplan-Meier survival curves were constructed and data were analyzed with a Cox proportional hazards model. RESULTS: None of 9 procedures in patients with the ipsilateral kidney contributing less than 25% of total renal function was successful. Among the 38 remaining benign ureteral stricture treatments with ipsilateral function 25% or greater with a median followup of 28.4 months among successful cases the 3-year success rate was 80%. No procedure failed beyond 11 months and there were 25 patients at risk beyond this point. Among the 30 remaining ureteroenteric stricture treatments with ipsilateral function 25% or greater the success rates at 1, 2 and 3 years were 73, 51 and 32%, respectively. Failures were noted during the first 36 months but none occurred later and 5 patients were at risk beyond this point. Overall, complete or tight strictures were less successfully treated. A nonischemic etiology, a stent 12F or greater and injection of triamcinolone into the bed of the incised stricture were associated with better outcome for strictures longer than 1 cm. CONCLUSIONS: Endoureterotomy of benign ureteral strictures is associated with an excellent outcome (80% success at 3 years). Endoscopic treatment of ureteroenteric strictures is less successful but still offers a reasonable first step (32% 3-year success rate). For all strictures failure is likely if ipsilateral renal function is poor. For strictures longer than 1 cm. use of a stent 12F or greater and injection of triamcinolone appear to be beneficial.

Female↗

PubMed1997

Preoperative assessment of ureteropelvic junction obstruction with endoluminal sonography and helical CT.

OBJECTIVE: Our objective was to compare the value of endoluminal sonography with the value of helical CT in the preoperative assessment of crossing vessels in patients with ureteropelvic junction (UPJ) obstruction. SUBJECTS AND METHODS: Thirteen patients with UPJ obstruction underwent contrast-enhanced helical CT with multiplanar reformations and endoluminal sonography. Imaging preceded surgery for UPJ repair. On imaging, vessels were considered significant if greater than or equal to 2 mm in diameter and within 1 cm of the UPJ. RESULTS: Three patients had no crossing vessels revealed by either study. On sonography, another patient had a vessel revealed with a diameter that varied between 1.3 and 2.2 mm; on CT no correlate was detected. The remaining nine patients had vessels revealed by both techniques. On CT, four patients had two vessels revealed and five patients had single vessels revealed for a total of 13 vessels revealed by CT. On sonography, five patients had two vessels revealed and five patients had single vessels revealed. Thus, 15 vessels were revealed by sonography. Both arteries and veins were revealed anterior, posterior, and medial to the UPJ; no lateral vessels were seen. Four patients underwent laparoscopy, during which the absence, presence, and location of vessels were found to correlate with sonography and helical CT. CONCLUSION: Endoluminal sonography and helical CT were similar in revealing crossing vessels in patients with UPJ obstruction.

Adolescent↗

PubMed1997

Use of intravenous contrast material during in situ extracorporeal shock wave lithotripsy of ureteral calculi.

PURPOSE: We prospectively studied the usefulness of contrast material to facilitate extracorporeal shock wave lithotripsy (ESWL) of ureteral calculi in situ. MATERIALS AND METHODS: Followup was available for 67 consecutive patients with ureteral calculi treated in situ (without ureteral catheterization) on an unmodified Dornier HM-3 lithotriptor. In 30 patients radiographic contrast material was administered to facilitate targeting of calculi. Intraoperative obstruction was determined by the lack of passage of contrast material beyond the calculus during treatment. Immediate postoperative obstruction was defined as prolonged retention of contrast material on a postoperative radiograph. RESULTS: Passage of contrast material beyond the calculus was not noted in 9 of 26 evaluable patients, 5 of whom appeared to have obstruction on postoperative radiography. Of these 5 patients 3 required immediate hospitalization for pain control, compared to none of those without intraoperative obstruction. The stone-free rates after ESWL, including success following adjunctive measures or repeat ESWL, were 83, 100 and 87% for calculi in the proximal, middle and distal ureter, respectively. Neither use of contrast material, nor intraoperative or postoperative obstruction altered the eventual success of ESWL. CONCLUSIONS: The administration of intravenous contrast material during ESWL allows for effective treatment of ureteral calculi that otherwise could not be imaged adequately without ureteral catheterization, and provides information valuable for short-term prognosis.

Contrast Media↗

PubMed1997

Long-term outcome of flexible ureterorenoscopy in the diagnosis and treatment of lateralizing essential hematuria.

PURPOSE: We identified the long-term outcome of ureterorenoscopic diagnosis and treatment of patients with lateralizing essential hematuria. MATERIALS AND METHODS: We reviewed retrospectively 17 patients with lateralizing essential hematuria treated with flexible ureterorenoscopy (15) or flexible percutaneous nephroscopy (2) with or without biopsy and electrocoagulation. Followup was longer than 24 months (average 60, range 24 to 116) in all patients. RESULTS: At followup 9 of the 17 patients (59%) were cured and 7 (41%) had recurrent bleeding. Discrete lesions occurred in 11 patients (64%), who were treated with electrocoagulation with 9 (82%) cured. All 3 patients (18%) with diffuse lesions had recurrent bleeding as did 2 of 3 (66%, 18% overall) with negative examinations. CONCLUSIONS: Ureterorenoscopy is an effective means of diagnosis and treatment of lateralizing essential hematuria. The majority of patients with lateralizing hematuria will have a discrete lesion that will respond to ureterorenoscopic electrocoagulation in the long-term. However, if the lesions are diffuse or the diagnostic examination is unreliable recurrent bleeding is likely.

Adult↗

PubMed1997

A multicenter clinical trial investigating the use of a fluoroscopically controlled cutting balloon catheter for the management of ureteral and ureteropelvic junction obstruction.

PURPOSE: We assessed the efficacy of a fluoroscopically controlled cutting balloon catheter for the treatment of ureteropelvic junction and ureteral strictures. MATERIALS AND METHODS: A multicenter trial was performed that included 66 endopyelotomies and 49 endoureterotomies. To our knowledge this study represents the largest number of patients with ureteropelvic junction obstruction and ureteral strictures tested with this device to date. RESULTS: With a mean followup of 7.8 months (range 1 to 17.9) the patency rate was 77% for endopyelotomy, with 72% of the primary and 100% of the secondary ureteropelvic junction obstructions remaining patent. The endoureterotomy patients were followed for an average of 8.7 months (range 1.2 to 17.0), with a patency rate of 55%. CONCLUSIONS: A cutting balloon endoscopic incision is effective in the majority of cases, with patency rates for endopyelotomies and endoureterotomies that mirror current endourological reports using other, albeit more time intensive and more invasive, incisional techniques.

Adolescent↗

PubMed1997

Laparoscopic adrenalectomy for solitary metachronous contralateral adrenal metastasis from renal cell carcinoma.

PURPOSE: We report our experience with laparoscopic adrenalectomy for malignant adrenal disease. MATERIALS AND METHODS: Between June 1995 and January 1996, 2 patients with a solitary metachronous contralateral adrenal metastasis from renal cell cancer were evaluated. Both patients had undergone radical nephrectomy for localized renal cancer 5 years previously. Laparoscopic transperitoneal adrenalectomy was performed. RESULTS: The laparoscopic procedures required 2.5 and 4.3 hours. Hospital stay was 3 and 4 days. The specimens weighed 98 and 81 gm. All surgical margins were free of metastatic clear cell cancer. Both patients were begun on prednisone and fludrocortisone replacement therapy. One patient experienced an increase in creatinine, which has since stabilized at 3.0 mg/dl. Neither patient had recurrent cancer at 11 and 16 months of followup. CONCLUSIONS: Laparoscopic adrenalectomy for metastatic renal cell cancer was performed successfully in 2 patients. However, the short-term benefits to the patient of earlier ambulation, decreased pain, minimal incisions and shortened convalescence must be weighted against the as yet unknown long-term (5 years) results.

Adrenal Gland Neoplasms↗

PubMed1997

Comparison of fibrin glue, laser weld, and mechanical suturing device for the laparoscopic closure of ureterotomy in a porcine model.

PURPOSE: We evaluated fibrin glue, laser welding, and a mechanical suturing device (Endo-Stitch) as alternatives to standard laparoscopic suturing with a free needle. METHODS: In 14 pigs, 22 linear proximal ureterotomies were closed laparoscopically with one of 4 different methods: fibrin glue, laser welding, Endo-Stitch suture placement (4-0 polyglactin), and free-needle suture placement (4-0 polyglactin). The ureterotomy was left open in 6 ureters. Acute leakage was tested by instillation of methylene blue. After 12 weeks, the ureters were assessed with radiography, ex-vivo pressure-flow studies, bursting pressures, and histology. RESULTS: All alternative closure techniques were more rapid than free-needle suturing, and less frequently allowed acute leakage. Closure with fibrin glue yielded significantly higher flow rates than control, whereas the other closure techniques yielded flow rates similar to that of unclosed ureters. All alternative closure methods demonstrated histological evidence of healing that were superior to free-needle suturing. In multifactorial analysis, leakage at the ureterotomy site was the factor most significantly associated with subsequent poor ex-vivo flow characteristics. CONCLUSIONS: All of the alternative laparoscopic ureteral closure methods compared favorably with standard free-needle suturing. Fibrin glue produced better radiographic findings, flow characteristics, and histology, suggesting that it currently has the most promise as an alternative or adjunct to laparoscopic suturing. Development of alternative laparoscopic techniques is ongoing, however, and thus the current state-of-the-art techniques used in this study may well be supplanted by other technologies in the future.

Animals↗

PubMed1997

Laparoscopic pneumodissection: results in initial 20 patients.

BACKGROUND: The efficiency of laparoscopic procedures has been hindered by a lack of instrumentation for blunt tissue dissection. We evaluated here the efficacy of a new 5-mm laparoscopic dissecting instrument, a pneumodissector. This instrument allows the surgeon to use short bursts of high-pressure carbon dioxide to bluntly dissect fatty tissue. STUDY DESIGN: In 20 patients undergoing a variety of laparoscopic procedures, a 5-mm laparoscopic pneumodissector was used. Subjective assessment of the efficacy of the instrument was recorded. In addition, acid-base changes were measured by blood gas determination, and serum chemistries were obtained before, during, and after the procedure. RESULTS: The pneumodissector enhanced dissection of the kidney, ureter, and major blood vessels and shortened the operative time for laparoscopic nephrectomy. Although statistically significant changes in acidbase values occurred with use of the pneumodissector, these changes were not clinically significant and were no different than what is normally seen during carbon dioxide pneumoperitoneum. CONCLUSIONS: Laparoscopic pneumodissection is a safe and efficacious technique for rapid blunt tissue dissection.

Acid-Base Equilibrium↗

PubMed1997

Incisional hernia after laparoscopic nephrectomy with intact specimen removal: caveat emptor.

PURPOSE: We report 5 cases of postoperative incisional hernia after laparoscopic nephrectomy with intact removal of the specimen. MATERIALS AND METHODS: During the last 5 years 29 patients underwent laparoscopic nephrectomy with intact removal of the resected specimen due to a large kidney and/or malignancy. Of these 29 patients 5 had a postoperative incisional hernia at the site of intact removal, including 3 with renal tumors and 2 with large polycystic kidneys due to adult onset autosomal dominant polycystic kidney disease. The records of these patients were reviewed to determine any specific factors that might relate to the development of this complication. RESULTS: An incisional hernia developed at the wound site in 5 patients (17%) 41 to 73 years old (mean age 53.4). Average body mass index for the patients was 34.2 (range 26 to 47). Average weight and size were 542 gm. and 20.3 x 10.3 cm., respectively, for the 3 resected malignant specimens and 1,975 gm. and 23.8 x 16.5 cm., respectively, for the 2 benign kidneys. A transverse lower flank muscle cutting incision (average 10.4 cm.) was performed to remove the resected kidney. Incisional hernias appeared after an average of 6.6 weeks postoperatively. Risk factors for a postoperative hernia included obesity in 80% of the patients, chronic renal insufficiency due to autosomal dominant polycystic kidney disease in 40%, postoperative pulmonary complication in 40% and metastatic cancer in 20%. CONCLUSIONS: Our experience has led us to avoid a lower flank port connecting incision for specimen removal. Instead we changed to a midline or subcostal incision in these patients. In addition, we believe that with the availability of the impermeable organ entrapment sacks there is less need for intact specimen removal even for renal tumors. Currently large benign kidneys (autosomal dominant polycystic kidney disease) are morcellated in situ to a suitable size for entrapment, while renal tumors are entrapped and morcellated directly. Presently our only indication for intact removal is in the case of a renal pelvic or caliceal transitional cell cancer.

Adult↗

PubMed1997

Laparoscopic ablation of peripelvic renal cysts.

PURPOSE: We describe and define the operative techniques, findings and results of laparoscopic ablation of peripelvic renal cysts. MATERIALS AND METHODS: One male and three female patients, ranging in age from 35 to 59 years, underwent laparoscopic ablation of symptomatic peripelvic cysts. All patients had symptoms of ipsilateral flank pain and obstruction. One patient had an episode of pyelonephritis before detection of the cyst, and 2 patients had concomitant stones within the obstructed system. Cysts ranged in size from 4 to 6 cm. Dissection was uniformly complex because of the depth to which the cyst extended into the renal parenchyma and the overlying renal vessels and collecting system. RESULTS: Operative times ranged from 315 to 390 minutes (mean 338 minutes). The average length of hospital stay was 2.75 days (range 2 to 4 days). Three of 4 patients (75%) had resolution of their symptoms and collecting system obstruction. One patient, the only case of a retroperitoneal approach, had recurrence of her symptoms and cyst 2 months after the operation and required open surgical repair. CONCLUSIONS: Laparoscopic ablation of peripelvic cysts is a challenging yet feasible procedure. Because of the medial location of these cysts, a transperitoneal approach may be preferable to retroperitoneal access alone.

Adult↗

PubMed1996

Pediatric endopyelotomy: the Washington University experience.

PURPOSE: Endopyelotomy has gained acceptance as minimally invasive therapy for ureteropelvic junction obstruction in adults. Its role in the treatment of pediatric ureteropelvic junction obstruction remains controversial. We report our experience with antegrade endopyelotomy for treating pediatric ureteropelvic junction obstruction. MATERIALS AND METHODS: A total of 17 patients 3 months to 17 years old underwent endopyelotomy as primary treatment for ureteropelvic junction obstruction (8) and after failed open pyeloplasty with secondary endopyelotomy performed a mean of 12 weeks after open pyeloplasty (9). Standard antegrade percutaneous techniques were used. Electrosurgical incision of the ureteropelvic junction at a posterolateral orientation was done in each case. Internal ureteral stents remained in place for 4 to 6 weeks postoperatively. RESULTS: In 5 of the 8 patients (62%) treated primarily the outcome was successful at a mean followup of 38 months (range 25 to 53). Failures occurred at 6 weeks, 3 months. In all 9 patients treated secondarily outcomes were successful at a mean followup of 59 months (range 16 to 110). CONCLUSIONS: Endopyelotomy as primary treatment of pediatric ureteropelvic junction obstruction remains controversial but it may be appropriate in select cases. On the other hand, endopyelotomy is safe and effective for pediatric patients in whom open pyeloplasty fails.

Adolescent↗

PubMed1996

Ureteral cell cultures II: Collagen production and response to pharmacologic agents.

PURPOSE: To investigate the in vitro response of ureteral cells to potentially anti-fibrotic agents. MATERIALS AND METHODS: Cultured human uroepithelial cells, smooth muscle cells, and myofibroblasts were assayed for proliferation and production of collagen types I and III, with and without the presence of hydrocortisone, colchicine, retinol, verapamil, and D-penicillamine. RESULTS: Hydrocortisone stimulated the proliferation of all three cell types and reduced the type I and type III collagen production by myofibroblasts and smooth muscle cells, respectively. Verapamil enhanced the growth of uroepithelial cells and decreased collagen III production by both uroepithelial and smooth muscle cells. D-penicillamine increased the proliferation of uroepithelial and smooth muscle cells, and inhibited collagen type III production by all three cell types. CONCLUSIONS: In vitro evidence suggests that hydrocortisone, verapamil, and D-penicillamine have effects that could favorably alter the healing of endoscopic ureteral incisions.

Cell Division↗

PubMed1996

Ureterolysis for extrinsic ureteral obstruction: a comparison of laparoscopic and open surgical techniques.

PURPOSE: We evaluated the role of laparoscopy in the management of extrinsic ureteral obstruction due to benign retroperitoneal fibrosis or ovarian pathology. The results of laparoscopic ureterolysis were compared to those of a contemporary series of open ureterolysis performed for the same pathological conditions. MATERIALS AND METHODS: We compared 6 patients undergoing unilateral laparoscopic ureterolysis for extrinsic ureteral obstruction to 7 undergoing open unilateral ureterolysis for similar pathological conditions. Patient demographic, operative, and early and late postoperative data were collected. RESULTS: Laparoscopic ureterolysis was associated with less intraoperative blood loss and need for parenteral pain medications, and significantly shorter hospital stay and convalescence than open surgery. Although there were no intraoperative or postoperative complications in the laparoscopy group, 1 patient in the open surgery group had an intraoperative ureteral avulsion and 4 had minor postoperative complications (blood transfusion, ileus and/or wound cellulitis). Operative time was longer in the laparoscopy group (255 versus 232 minutes). Subjective followup with an analog pain scale and/or telephone interview showed improvement in all patients in the laparoscopy group and all 6 contacted in the open surgery group. Likewise, excretory urography and/or renal scan showed improved renal function and relief of obstruction in all patients. CONCLUSIONS: Laparoscopic unilateral ureterolysis for extrinsic ureteral obstruction is a less morbid, yet equally effective procedure with several clinical advantages over conventional open surgical ureterolysis.

Adolescent↗

PubMed1996

Acucise endopyelotomy: assessment of long-term durability.

PURPOSE: We evaluated the long-term efficacy of Acucise endopyelotomy. MATERIALS AND METHODS: A total of 28 patients with 28 ureteropelvic junction obstructions was reevaluated 2 or more years after Acucise endopyelotomy (mean 32.5 months). Subjective analysis was done with analog pain scales and objective analysis was performed with diuretic renal scintigraphy. RESULTS: Subjective followup was available for all 28 patients, and 17 (61%) had a favorable response with 36% totally free of pain and 25% markedly improved. Among 26 patients with objective followup (93%) 21 (81%) had a patient ureteropelvic junction based on a diuretic renal scan with a half-time of less than 10 minutes or a normal Whitaker test. Among all regularly followed patients failure occurred uniformly within 1 year. CONCLUSIONS: Acucise endopyelotomy is an effective and durable method for treating ureteropelvic junction obstruction.

Adolescent↗

PubMed1996

Laparoscopy for adult polycystic kidney disease: a promising alternative.

The purpose of this study was to evaluate the efficacy of laparoscopy in managing patients with abdominal symptoms from autosomal dominant polycystic kidney disease (ADPKD). From April 1993 to July 1995, four patients with ADPKD underwent seven laparoscopic procedures: five cyst decortications were performed in two patients using a laparoscopic ultrasound unit and two laparoscopic nephrectomies were performed in two patients with end-stage renal failure. The mean operative time was 207 minutes for laparoscopic cyst decortication and 272 minutes for laparoscopic nephrectomy. The two nephrectomy specimens were 2,200 g and 1,750 g, respectively. The mean intraoperative blood loss was 85 mL. The patients resumed their oral intake within 10 hours after laparoscopic cyst decortication and within 16 hours after laparoscopic nephrectomy. The mean amount of parenteral analgesics required postoperatively was 12 mg morphine sulfate for cyst decortication and 30 mg morphine sulfate for nephrectomy. The mean hospital stay was 3 days for cyst decortication and 3.5 days for nephrectomy. The patients returned to their usual activities after an average of 2 weeks. Based on pain analog scales, all the patients have shown marked reduction in their symptoms (average, 90%) during an average follow-up period of 6.6 months. Laparoscopic cyst decortication and nephrectomy are effective minimally invasive treatment options for patients with adult polycystic kidney disease who are experiencing abdominal symptoms due to marked renal enlargement. We believe that by using a laparoscopic ultrasound unit, most renal cysts may be safely removed, and if need be, even "giant" kidneys can be removed laparoscopically. To the best of our knowledge, the two nephrectomy specimens in this study represent the largest kidneys removed laparoscopically to date and the first laparoscopic nephrectomies in ADPKD patients.

Adult↗

PubMed1996

Acucise endopyelotomy: evolution of a less-invasive technology.

Since its introduction in 1993, the electrosurgical cutting balloon device (Acucise) has been utilized for endopyelotomies by a number of investigators. The fact that the procedure can be performed in a completely retrograde fashion under fluoroscopic guidance without percutaneous access has made Acucise endopyelotomy appealing to many urologists. To date, overall Acucise endopyelotomy success rates ranging from 66% to 84% have been reported. The average hospital stay has ranged from 1.7 to 3.7 days, and serious complications have been rare (transfusion 0-2%, bleeding necessitating embolization 0-3%). On the basis of its track record and its minimally invasive nature, a compelling argument can be made for use of the Acucise device whenever an endopyelotomy is indicated.

Catheterization↗