Timothy G. Schuster

COMPLICATIONS OF URETEROSCOPY: ANALYSIS OF PREDICTIVE FACTORS

PURPOSE Although overall and major complication rates of 10% to 20% and 0% to 6%, respectively, have been observed in large series of ureteroscopy, to our knowledge no systemic analysis to determine factors predictive of these complications has been reported. MATERIALS AND METHODS We retrospectively reviewed all ureteroscopies performed at our institution for calculous disease from January 1997 through September 1999. A total of 322 procedures were performed by 5 attending surgeons. Intraoperative and immediate postoperative complications were identified. Bivariate and multivariate analysis was performed to identify associated factors with ureteral perforation and postoperative complications as the dependent variables. RESULTS Bivariate analysis showed a significant association of ureteral perforation with increased operative time (p = 0.0001). In addition, we noted a significant association of postoperative complications with stones in the kidney (p = 0.0004), operative time (p = 0.05) and decreased surgeon experience (p = 0.0035) as well as a trend toward significance for the type of ureteroscope used (p = 0.0609). In multivariate logistic regression models ureteral perforation remained highly associated with operative time (p = 0.0005) when controlling for the other factors. Similarly decreased surgeon experience and a stone in the kidney were predictive of postoperative complications when controlling for the other factors (p = 0.004). CONCLUSIONS Longer duration of the ureteroscopic procedure is strongly associated with ureteral perforation. The likelihood of immediate postoperative complications is greater when renal calculi are treated and less when the surgeon is more experienced.

URETEROSCOPY FOR THE TREATMENT OF UROLITHIASIS IN CHILDREN

PURPOSE Ureteroscopy for treating urolithiasis in prepubertal children has become more common with the advent of smaller instruments. We reviewed our experience with ureteroscopy for urolithiasis in this cohort of patients as well as the literature using this treatment modality in children. MATERIALS AND METHODS Between 1994 and 2000 we performed 27 ureteroscopic stone extractions in 25 children. Ureteroscopy was done in a manner similar to that in adults. Ureteral dilation was performed when necessary to access the ureter. A stent was placed postoperatively if there was significant ureteral trauma. RESULTS Of the 25 children 13 were male and 12 were female. Average age was 9.2 years (range 3 to 14). Stones were 2 to 12 mm. in greatest diameter (average 6). Of the 27 procedures the ureteral orifice was dilated before stone treatment in 15 (56%), while in 19 (70%) a stent was placed afterward. No intraoperative and 2 postoperative complications were identified. Overall 92% of the children were rendered stone-free after 1 procedure and 100% were stone-free after 2. CONCLUSIONS Ureteroscopy for urolithiasis in prepubertal children is safe and effective. Routine ureteral dilation and ureteral stent placement are not always necessary in these patients.

Isolation of motile spermatozoa from semen samples using microfluidics

A microfluidic device was designed with two parallel laminar flow channels where non-motile spermatozoa and debris would flow along their initial streamlines and exit one outlet, whereas motile spermatozoa had an opportunity to swim into a parallel stream and exit a separate outlet. Motile sperm samples were prepared with density gradient separation (n = 5). Sperm motility was assessed the following day after exposing aliquots to polydimethylsiloxane (PDMS) used to construct the device. There was no difference in sperm motility when compared with unexposed aliquots (P > 0.05). Unprocessed semen samples (n = 10) were placed in wider channels and sperm motility and strict morphology were assessed from sorted outlets. Sperm motility increased from 44 +/- 4.5% to 98 +/- 0.4% (P < 0.05) and morphology increased from 10 +/- 1.05% to 22 +/- 3.3% (P < 0.05) following processing. Finally, density gradient prepared samples (n = 6) containing 5 x 10(6) motile spermatozoa/ml and 50 x 10(6) round immature germ cells/ml were sorted and assessed in a similar fashion. The ratio of motile spermatozoa to round immature germ cells in the wide inlet (1:10) was significantly improved in the thin outlet (33:1) (P < 0.05). This microfluidic device provides a novel method for isolating motile, morphologically normal spermatozoa from semen samples without centrifugation. This technology may prove useful in isolating motile spermatozoa from oligozoospermic samples, even with high amounts of non-motile gamete and/or non-gamete cell contamination. A movie sequence showing streaming and sorting of spermatozoa may be purchased for viewing on the internet at www.rbmonline.com/Article/847 (free to web subscribers).

REVISION RATE AFTER ARTIFICIAL URINARY SPHINCTER IMPLANTATION FOR INCONTINENCE AFTER RADICAL PROSTATECTOMY: ACTUARIAL ANALYSIS

PURPOSE We determined the actuarial revision rate for artificial urinary sphincters implanted in patients who were incontinent after radical prostatectomy. MATERIALS AND METHODS We reviewed the records of 70 consecutive patients who were incontinent after radical prostatectomy and who underwent primary artificial urinary sphincter implantation at the University of Michigan between 1984 and 1999. Questionnaires were mailed to all patients with an indwelling device, and telephone calls were placed to those who did not respond to the mailing. Information about surgical revision and current continence status was obtained from chart review and questionnaire response. The Kaplan-Meier curves for actuarial freedom from operative revision were constructed. RESULTS Of the 66 patients with available postoperative data 24 (36%) required reoperation at a mean followup of 41 months. The 5-year actuarial rate for freedom from any operative revision was 50%, and the corresponding rate for cuff revision was 60%. A single operative revision did not predispose the patient to further revision. Questionnaire data indicated a continence rate of 80% (range 0 to 2 pads). CONCLUSIONS Approximately half of the patients who were incontinent after radical prostatectomy may expect to undergo operative revision within 5 years after artificial urinary sphincter implantation. Despite this high reoperation rate, an excellent level of continence is maintained.

Ureteroscopic Treatment of Lower Pole Calculi: Comparison of Lithotripsy In Situ and After Displacement

Purpose: Ureteroscopic management is a viable option for lower pole calculi less than 2 cm. Recently a technique was described to displace the calculus into a more accessible calix using a nitinol basket or grasper before lithotripsy. We compared the efficacy and safety of this technique with in situ treatment of small and intermediate lower pole calculi.Materials and Methods: We retrospectively reviewed the records of 95 ureteroscopy cases performed at our institution from January 1997 through August 2001 for renal calculi located only in the lower pole. Preoperative patient characteristics, stone size, operative details, complications and outcomes were compared for calculi treated in situ and those displaced before treatment.Results: Adequate followup was available on 78 patients. Patients in the displacement group were statistically older, more often had a preoperative indwelling ureteral stent and had a mean operative time that was 16 minutes longer (p = 0.04). Average stone diameter in the in situ an...

Ureteroscopic treatment of renal calculi in morbidly obese patients: A stone-matched comparison

OBJECTIVES To report a matched comparison of morbidly obese (MO) patients and normal weight (NW) patients who underwent ureteroscopic (URS) treatment of renal calculi. Shock wave lithotripsy and percutaneous nephrostolithotomy may be precluded in MO patients, and URS treatment offers a minimally invasive alternative. METHODS We retrospectively reviewed the charts of patients who underwent URS at our institution between 1997 and 2000. Fifty-four patients underwent URS treatment solely for renal calculi. Sixteen MO patients underwent 18 procedures. Thirty-eight NW patients, who underwent 39 procedures, were matched to the MO patients by stone location and size. Stones were categorized by location and size, less than 10 mm or 10 mm or greater. The factors and outcomes assessed were stone length, operative time, presence of a ureteral stent, success, and complications. RESULTS The overall success rate was 83% (15 of 18 procedures) for MO patients and 67% (26 of 39 procedures) for NW patients, but this difference was not significant (P = 0.23). The difference in the success rate for renal calculi 10 mm or greater (100% versus 38%) approached significance (P = 0.09). This may be related to other distinctions between the groups. URS treatment was often a salvage therapy in the NW group after other modalities failed. No significant differences were found between the other outcomes. CONCLUSIONS URS treatment of renal calculi when matched for location and size is as successful and no more morbid in MO than in NW patients. URS treatment of renal calculi is a safe and effective first-line treatment for renal calculi in MO patients.

POSTOPERATIVE ILEUS AFTER ABDOMINAL SURGERY

Despite significant advancements in the care of the surgical patient, little progress has been made in the understanding and treatment of postoperative ileus (PI). Cystectomy with urinary diversion and complex urinary tract reconstruction using bowel are procedures in urologic surgery associated with some of the greatest hospital costs and longest lengths of stay (LOS). Improvements in costs, patient satisfaction, and complication rates often accompany the institution of “care pathways” designed to minimize the variability between practice patterns and postoperative care. 1 Cystectomy is a procedure in which reductions in LOS, costs, and patient morbidity have been difficult to achieve. A primary contribution to the longer LOS in the urologic patients undergoing bowel surgery is the relatively slow return of normal gastrointestinal function and, in many instances, PI that translates into a prolonged hospital stay of days to weeks. Radical cystectomy patients often feel poorly for 4 to 8 weeks after surgery, and loss of appetite is a common feature. A weight loss of 10 to 20 lb is not uncommon. The ability to reestablish normal eating sooner would provide a substantial benefit to the patient and healthcare costs alike. We examined the current understandings of bowel function physiology and treatments of PI after major abdominal surgery. Clinicians use a variety of definitions to describe the changes in bowel activity that occur after abdominal surgery, with no standard nomenclature in place. Gastrointestinal motility is clearly impaired after surgical manipulation of the bowel to some degree. Each segment of the gastrointestinal tract recovers motility at a different rate after surgical manipulation. The small intestines typically recover motility within several hours, the stomach within 24 to 48 hours, and the colon in 3 to 5 days. It is this delay in coordinated movement of the gastrointestinal tract that is often referred to as PI. This is in contrast to a mechanical bowel obstruction resulting from structural abnormalities that cause motility disorders. Postoperatively, some patients experience a prolonged inhibition of coordinated bowel activity that causes accumulation of secretions and gas, resulting in nausea, vomiting, abdominal distension, and pain. This prolonged inhibition, which can take days to weeks to resolve, is often referred to as postoperative paralytic ileus. However, because of the lack of standard definitions, many physicians view PI and postoperative paralytic ileus as a continuum and collectively refer to the events as PI.

Routine placement of ureteral stents is unnecessary after ureteroscopy for urinary calculi.

OBJECTIVES To report a matched comparison of patients with and without stenting after ureteroscopy for calculi, including middle or proximal ureteral and renal calculi. The elimination of routine stenting after ureteroscopy would prevent stent pain, minimize the need for re-instrumentation, and reduce costs-as long as efficacy and safety are not diminished. METHODS Of 318 patients who underwent ureteroscopy, 81 (25%) did not have a ureteral stent placed. Of those, 51 were suitable for analysis and included patients with distal ureteral (n = 22), middle or proximal ureteral (n = 11), and renal calculi (n = 18). This cohort was matched to a stented group by stone size and location. RESULTS The preoperative characteristics of the groups were similar. A stone-free rate of 86% and 94% was achieved in the stented and nonstented groups, respectively (P = 0.32). Complications in the nonstented group were less frequent (flank pain in 3 and postoperative nausea in 1) than in the stented group (hospital visits for flank pain in 12, persistent nausea and vomiting in 1, sepsis in 1, perinephric hematoma in 1, and urinary retention in 1) (total of 4 versus 16, P = 0.025). CONCLUSIONS Ureteroscopy for distal ureteral stones without ureteral stent placement has been previously described. Our experience expands to include the elimination of stent placement after ureteroscopy for middle or proximal ureteral (22%) and renal (35%) calculi. Our data suggest that after ureteroscopies with short operative times and minimal ureteral trauma, ureteral stents may not be necessary, even if proximal ureteral or renal ureteroscopy has been performed.

Safety and efficacy of same-session bilateral ureteroscopy.

PURPOSE Same-session ureteroscopy for bilateral urinary calculi would potentially reduce costs and the need for a second anesthetic compared with staged procedures. We sought to establish the safety and efficacy of same-session bilateral ureteroscopy relative to procedures for staged bilateral and multiple unilateral calculi in the context of contemporary instrumentation. PATIENTS AND METHODS A series of 626 consecutive patients underwent ureteroscopy for calculi between January 1997 and August 2001. Among these, 34 patients with bilateral calculi (11 staged and 23 treated in one sitting) and 54 patients with multiple unilateral calculi in distinct locations were included in this study. Multivariable regression was used to determine the association of patient-specific and technical factors with postoperative morbidity. RESULTS Stone-free rates were similar in the two groups and ranged from 50% to 100% depending on stone location. Postoperative complications occurred in 6 (11%) and 3 (14%) of the patients treated for multiple unilateral and for bilateral calculi in a staged procedure, respectively, compared with 7 (29%) of those undergoing same-session bilateral ureteroscopy (P = 0.12). Logistic regression revealed that same-session bilateral ureteroscopy (odds ratio [OR] 4.0; P = 0.02) and absence of a postoperative stent (OR 1.7; P = 0.03) were associated with added morbidity. However, the cumulative risk of performing staged bilateral procedures (14% per procedure) approximated that of bilateral ureteroscopy in one sitting (29%). CONCLUSION Bilateral ureteroscopy carries an increased risk of postoperative morbidity. The risk is proportional to the number of renal units treated and may be assumed at once (e.g., same-session) or over time (e.g., staged) as it applies to patients requiring bilateral ureteroscopy.

Insertional mutation of the motor endplate disease (med) locus on mouse chromosome 15

Homozygous transgenic mice from line A4 have an early-onset progressive neuromuscular disorder characterized by paralysis of the rear limbs, muscle atrophy, and lethality by 4 weeks of age. The transgene insertion site was mapped to distal chromosome 15 close to the locus motor endplate disease (med). The sequence of mouse DNA flanking the insertion site junctions was determined. A small (< 20 kb) deletion was detected at the insertion site, with no evidence of additional rearrangement of the chromosomal DNA. Noncomplementation of the transgene-induced mutation and med was demonstrated in a cross with medJ/+mice. The new allele is designated medTgNA4Bs (medtg). The homologous human locus MED was assigned to chromosome 12. Synaptotagmin 1 and contactin 1 were eliminated as candidate genes for the med mutation. The transgene-induced allele provides molecular access to the med gene, whose function is required for synaptic transmission at the neuromuscular junction and long-term survival of cerebellar Purkinje cells.