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Ureteral Stricture in an Animal Model
Ureter/Urinary Diversion 1122
1123
EXPERIMENTAL COMPARISON ON THE RESULTS OF TWO DIFFERENT CALIBER REDUCING MEGAURETER REIMPLANTING TECHNIQUES. "'Herman H. R. Bakker, *'Pieter J. Klapper, Amsterdam, Neth. Presentation to be made by Dr. Bakker. The growing piglet is found to be a suitable model to create an obstructive megaureter in short time. These experimentally induced megaureters are reconstructed and reimplanted in the bladder via two well established surgical techniques: 1. ureteral reduction plasty according Hendren. 2. folding under procedure. With help of pressure-flow studies and microangiography of the delicate, vulnerable bloodsupply of the reconstructive ureters, both techniques could be compared and judged on its merits. From the experimental research can be concluded that the folding under procedure had a better vasculature preserva' tion than the Hendren tailoring technique. From this point of view it is better to fold the megaureter as a calibre reducting messure. ·
URETERAL STRICTURE IN AN ANIMAL MODEL. Eugene V. Kramolowsky, Iowa City, IA The success rate for endourologic treatment of human ureteral strictures is about 50% with short-term follow-up. The reasons for therapeutic failures are unknown as is the optimal treatment. We have developed a ureteral stricture in a pig animal model simulating that seen after injury to the human ureter. Four percent formalin was used to induce ureteral strictures in female pigs. Ureters were exposed in a 20-minute procedure, using an extraperitoneal approach. One animal, used as a control, had surgical exposure without formalin treatment, and developed no stricture. Animals were divided into two groups. Ureters of Group I animals (3) were treated superficially with formalin for ten minutes and lee was injected circumferentially into the wall. Ureters in Group II animals (3) received only superficial formalin treatment. An area of 0,5, 1 or 2cm was treated in the midportion of each ureter with the contralateral ureter used as a control. Animals were evaluated at 10-12 weeks by IVP, antegrade, retrograde and Whitaker tests, All animals developed marked delayed function or nonfunction on IVP with antegrade/retrograde showing extensive hydroureteronephrosis to the treated area. Two of the three animals in Group I showed no flow of contrast through the treated area. Pathologic examination displayed obliteration of the lumen, However, retrograde examination in Group II showed narrowing of the lumen in the treated ureter. Pathologic specimens from this group resemble that of a human stricture with H&E and trickb.ome staining demonstrating a narrowed lumen lined by transitional epithelium and replacement of ureteral smooth muscle by collagen, The strictured· area measures 0.5-0.Bcm in length. Animals are being followed at two-week intervals to determine time sequence of stricture development. Hydronephrosis develops at two weeks and strictures seen on retrograde at four weeks. This model, resembling a human ureteral stricture, _is readily amenable to study, including balloon and rigid dilation and intraureteral incisions.
1124
1125
EFFECTIVENESS Of SMALL VERSUS LARGE URETERAL STENTS IN CAUSING URETERAL DILATATION.
Donald P. Griffith, Houston, made by Dr. Neerhut)
Gregory R. Neerhut• and
TX
(Presentation to be
Placement of a Oouble-J ureteral etent causes ureteral dilatation. Variables that may influence the degree of dilatation include duration of stenting, composition of the stent and caliber of the stent. The aim of t~is study was to determine if a similar degree of dilatation could be achieved by placement of a small caliber stent as with a larger atent. fourteen doge, ell with normal intravenous pyelograms were studied. In each dog one ureter was &tented and the other ureter was the control. Seven of the dogs received a #7 french Double-J ureteral stent and the other 7 dogs received the sam~ etent, incised longitudinally eo that its new circumference was #3 French. The stents were placed via an open cystotomy. Seven days later urine was cultured, the bladder reopened and the stent removed. Intravenous pyelography was performed 30 minutes later, and the animals were sacrificed. The ureters were exCised and their volumes determined by low pressure perfusion (14 cm water) with saline. They were e~amined histologically. Comparison between stented and ~antral ureters was by ureteral volume, ureters! image on IVP analysis, and histology.
Results suggest no significant difference between the dilatation achieved by the #3 and #7 French stents. This study was supported by a grant from the Surgitek Corporation.
KOCK CONTINENT ILEAL RESERVOIR-SUMMARY OF 12 CASES DONE IN PRIVATE PRACTICE. Herbert W. Riemenschneider and *Louis C. Galdieri, Columbus, OH (Presentation to be made by Dr. Riemenschneider) This st~dy reviews th~ experience with twelve patients who required urinary diversion. The reasons for diversion include cystectomy for malignancy, incontinence caused by neuropathic bladder dysfunction and exstrophy, The Kock Ileal Reservoir is the exclusive method used, Specific attention to patient selection in terms of age, inter-current disease and obesity is critical, The results are good; continence in ten of twelve patients. There were two postoperative deaths, one from pulmonary emboli, another from peritonitis and sepsis, One patient required revision because of extussusception of the efferent limb. The experience encompasses twenty-eight months. The period of follow-up ranges from twenty-eight months to one month. Development of a team consisting of surgeons and perioperative personnel familiar with the integral steps of the procedure is fundamental. The familiarity can be acquired through study of the literature, animal laboratory experience and expert instruction in the clinical setting particularly in operative experience. All of these steps are essential to the success of the project. Objective and subjective assessment of the patients in this series, with the exception of the two mortalities, demonstrates that there has been a dramatic improvement in style and quality of life,
384A
1123
EXPERIMENTAL COMPARISON ON THE RESULTS OF TWO DIFFERENT CALIBER REDUCING MEGAURETER REIMPLANTING TECHNIQUES. "'Herman H. R. Bakker, *'Pieter J. Klapper, Amsterdam, Neth. Presentation to be made by Dr. Bakker. The growing piglet is found to be a suitable model to create an obstructive megaureter in short time. These experimentally induced megaureters are reconstructed and reimplanted in the bladder via two well established surgical techniques: 1. ureteral reduction plasty according Hendren. 2. folding under procedure. With help of pressure-flow studies and microangiography of the delicate, vulnerable bloodsupply of the reconstructive ureters, both techniques could be compared and judged on its merits. From the experimental research can be concluded that the folding under procedure had a better vasculature preserva' tion than the Hendren tailoring technique. From this point of view it is better to fold the megaureter as a calibre reducting messure. ·
URETERAL STRICTURE IN AN ANIMAL MODEL. Eugene V. Kramolowsky, Iowa City, IA The success rate for endourologic treatment of human ureteral strictures is about 50% with short-term follow-up. The reasons for therapeutic failures are unknown as is the optimal treatment. We have developed a ureteral stricture in a pig animal model simulating that seen after injury to the human ureter. Four percent formalin was used to induce ureteral strictures in female pigs. Ureters were exposed in a 20-minute procedure, using an extraperitoneal approach. One animal, used as a control, had surgical exposure without formalin treatment, and developed no stricture. Animals were divided into two groups. Ureters of Group I animals (3) were treated superficially with formalin for ten minutes and lee was injected circumferentially into the wall. Ureters in Group II animals (3) received only superficial formalin treatment. An area of 0,5, 1 or 2cm was treated in the midportion of each ureter with the contralateral ureter used as a control. Animals were evaluated at 10-12 weeks by IVP, antegrade, retrograde and Whitaker tests, All animals developed marked delayed function or nonfunction on IVP with antegrade/retrograde showing extensive hydroureteronephrosis to the treated area. Two of the three animals in Group I showed no flow of contrast through the treated area. Pathologic examination displayed obliteration of the lumen, However, retrograde examination in Group II showed narrowing of the lumen in the treated ureter. Pathologic specimens from this group resemble that of a human stricture with H&E and trickb.ome staining demonstrating a narrowed lumen lined by transitional epithelium and replacement of ureteral smooth muscle by collagen, The strictured· area measures 0.5-0.Bcm in length. Animals are being followed at two-week intervals to determine time sequence of stricture development. Hydronephrosis develops at two weeks and strictures seen on retrograde at four weeks. This model, resembling a human ureteral stricture, _is readily amenable to study, including balloon and rigid dilation and intraureteral incisions.
1124
1125
EFFECTIVENESS Of SMALL VERSUS LARGE URETERAL STENTS IN CAUSING URETERAL DILATATION.
Donald P. Griffith, Houston, made by Dr. Neerhut)
Gregory R. Neerhut• and
TX
(Presentation to be
Placement of a Oouble-J ureteral etent causes ureteral dilatation. Variables that may influence the degree of dilatation include duration of stenting, composition of the stent and caliber of the stent. The aim of t~is study was to determine if a similar degree of dilatation could be achieved by placement of a small caliber stent as with a larger atent. fourteen doge, ell with normal intravenous pyelograms were studied. In each dog one ureter was &tented and the other ureter was the control. Seven of the dogs received a #7 french Double-J ureteral stent and the other 7 dogs received the sam~ etent, incised longitudinally eo that its new circumference was #3 French. The stents were placed via an open cystotomy. Seven days later urine was cultured, the bladder reopened and the stent removed. Intravenous pyelography was performed 30 minutes later, and the animals were sacrificed. The ureters were exCised and their volumes determined by low pressure perfusion (14 cm water) with saline. They were e~amined histologically. Comparison between stented and ~antral ureters was by ureteral volume, ureters! image on IVP analysis, and histology.
Results suggest no significant difference between the dilatation achieved by the #3 and #7 French stents. This study was supported by a grant from the Surgitek Corporation.
KOCK CONTINENT ILEAL RESERVOIR-SUMMARY OF 12 CASES DONE IN PRIVATE PRACTICE. Herbert W. Riemenschneider and *Louis C. Galdieri, Columbus, OH (Presentation to be made by Dr. Riemenschneider) This st~dy reviews th~ experience with twelve patients who required urinary diversion. The reasons for diversion include cystectomy for malignancy, incontinence caused by neuropathic bladder dysfunction and exstrophy, The Kock Ileal Reservoir is the exclusive method used, Specific attention to patient selection in terms of age, inter-current disease and obesity is critical, The results are good; continence in ten of twelve patients. There were two postoperative deaths, one from pulmonary emboli, another from peritonitis and sepsis, One patient required revision because of extussusception of the efferent limb. The experience encompasses twenty-eight months. The period of follow-up ranges from twenty-eight months to one month. Development of a team consisting of surgeons and perioperative personnel familiar with the integral steps of the procedure is fundamental. The familiarity can be acquired through study of the literature, animal laboratory experience and expert instruction in the clinical setting particularly in operative experience. All of these steps are essential to the success of the project. Objective and subjective assessment of the patients in this series, with the exception of the two mortalities, demonstrates that there has been a dramatic improvement in style and quality of life,
384A