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Biomedical subjects

Gerhard J Fuchs

Publications and source records attributed to Gerhard J Fuchs.

12 recordsLinked to original sources
PubMed2006

Simultaneous bilateral retrograde intrarenal surgery for stone disease in patients with significant comorbidities.

BACKGROUND AND PURPOSE: Advances in endoscopic equipment have allowed urologists to access stones in virtually any location in the upper tracts. Where clinically appropriate, this approach may represent the preferred treatment option, regardless of stone size. We report the first description of simultaneous bilateral retrograde intrarenal surgery (SB-RIRS) in patients with both significant upper-tract stone burdens and comorbidities such as morbid obesity or heart disease. PATIENTS AND METHODS: Between September 2003 and April 2004, three men and one woman with an average of 62 years underwent a total of seven sessions of SB-RIRS. All four patients were referred from other urologists after failing prior treatments, including shockwave lithotripsy (five sessions) and RIRS (two sessions). The average stone burden was 8.8 cm. The procedures were performed by two surgeons operating simultaneously using two sets of video/holmium laser equipment. Flexible (7.5F) ureteroscopes were used to fragment and basket stone debris without the use of ureteral access sheaths. RESULTS: Three patients underwent a scheduled second-stage procedure to ensure adequate stone clearance. The average total and SB-RIRS-specific operative times were 256 and 131 minutes for the initial procedure and 235 and 95 minutes for the second-stage procedure, respectively. No major complications were noted. CONCLUSION: Simultaneous bilateral RIRS is an appropriate treatment option for stone patients with significant comorbidities.

Aged↗
PubMed2005

Newly designed laparoscopic retractable dissector and suture passer.

We introduce a novel laparoscopic instrument that performs as a dissector and retractable suture passer in preparation for intracorporeal knot tying. The newly designed instrument was developed at our institution to duplicate techniques of vessel ligation in open surgery.

Animals↗
PubMed2005

Looped silk tie: surgical technique for management of the renal vein during laparoscopic live-donor nephrectomy.

Laparoscopic live-donor nephrectomy has revolutionized the field of kidney transplantation and has been adopted in many tertiary centers as the method of choice in procuring kidneys. While standard techniques for laparoscopic live-donor nephrectomy have been well described in the literature, there continues to be ample discussion about renal-vein ligation. Endo-GIA and other commonly used vascular stapling devices can be costly and prone to mechanical failures and may not be applicable in certain anatomic situations. Vascular clips, although simple to use for arteries, are difficult to apply to large renal veins. To address these issues, we describe a simple, cost-effective method of control that can be used for both right and left renal veins, using a loop constructed from a 0 silk tie.

Adult↗
PubMed2005

Laparoscopic skills training using a webcam trainer.

PURPOSE: Many sophisticated and expensive trainers have been developed to assist surgeons in learning basic laparoscopic skills. We developed an inexpensive trainer and evaluated its effectiveness. MATERIALS AND METHODS: The webcam laparoscopic training device is composed of a webcam, cardboard box, desk lamp and home computer. This homemade trainer was evaluated against 2 commercially available systems, namely the video Pelvitrainer (Karl Storz Endoscopy, Culver City, California) and the dual mirror Simuview (Simulab Corp., Seattle, Washington). The Pelvitrainer consists of a fiberglass box, single lens optic laparoscope, fiberoptic light source, endoscopic camera and video monitor, while the Simuview trainer uses 2 offset, facing mirrors and an uncovered plastic box. A total of 42 participants without prior laparoscopic training were enrolled in the study and asked to execute 2 tasks, that is peg transfer and pattern cutting. Participants were randomly assigned to 6 groups with each group representing a different permutation of trainers to be used. The time required for participants to complete each task was recorded and differences in performance were calculated. Paired t tests, the Wilcoxon signed rank test and ANOVA were performed to analyze the statistical difference in performance times for all conditions. RESULTS: Statistical analyses of the 2 tasks showed no significant difference for the video and webcam trainers. However, the mirror trainer gave significantly higher outcome values for tasks 1 and 2 compared to the video (p = 0.01 and <0.01) and webcam (p = 0.04 and <0.01, respectively) methods. ANOVA indicated no overall difference for tasks 1 and 2 across the orderings (p = 0.36 and 0.99, respectively). However, by attempt 3 the time required to complete the skill tests decreased significantly for all 3 trainers (each p <0.01). CONCLUSIONS: Our homemade webcam system is comparable in function to the more elaborate video trainer but superior to the dual mirror trainer. For novice laparoscopists we believe that the webcam system is an inexpensive and effective laparoscopic training device. Furthermore, the webcam system also allows instant recording and review of techniques.

Clinical Competence↗
PubMed2005

Bladder reconstitution with bone marrow derived stem cells seeded on small intestinal submucosa improves morphological and molecular composition.

PURPOSE: Tissue engineering has been used for bladder augmentations with small intestinal submucosa (SIS). Although favorable short-term outcomes have been reported, long-term followup has been poor. We investigate whether tissue engineering with stem cells improves the morphological and genetic composition. MATERIALS AND METHODS: A total of 33 Lewis rats (Harlan Laboratories, Indianapolis, Indiana) were used to investigate bladder augmentations with 4-layer SIS in certain groups, including the control group (sham operation), partial cystectomy with oversewn defect group (OG), augmentation with unseeded SIS group (USG) and augmentation with stem cell seeded SIS group (SSG). Bladders from 4 rats per group were harvested 1 and 3 months after surgery. Morphological analyses were performed using Masson's trichrome and immunohistochemical staining with cytokeratin AE1/AE3, smooth muscle alpha-actin and S100. Gene expression was evaluated using quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for collagen I (CI), collagen III (CIII), cytokeratins 8 and 19, and smooth muscle myosin heavy chain (MHC). RESULTS: At 1 month trichrome staining revealed collagen admixed with indiscrete cells and morphology similar to that in controls in USG and SSG, respectively. Discrete smooth muscles fascicles and S100 staining were found in all groups except USG. Organized urothelium with increased basal cell layer staining was present in controls and SSG only. At 3 months increased collagen formation was present in OG and USG. Immunostaining showed hyperplasia of the urothelium with increased staining of the basal cell layer, discrete muscle fascicles and positive nerve staining in all groups. Using quantitative RT-PCR expression levels in SSG were more improved than in USG, especially for CI, CIII and MHC. This was further evident at 3 months when CI and CIII were over expressed in OG and USG but not in the control group or SSG. Furthermore, RT-PCR showed that cytokeratins 8 and 19, and MHC had greater expression levels in SSG than in USG. CONCLUSIONS: Bladder reconstitution occurs more rapidly using stem cell seeded SIS. Although in USG and SSG all 3 cellular constituents appear to develop by 3 months, only SSG had gene expression levels similar to those in controls. The results suggest an explanation for the fibrosis noted in unseeded SIS bladder augmentations and the possible solution using stem cells.

Animals↗
PubMed2005

Multi-institutional validation study of neural networks to predict duration of stay after laparoscopic radical/simple or partial nephrectomy.

PURPOSE: We developed models to predict post-laparoscopic radical or simple nephrectomy (LapNx) and post-laparoscopic partial nephrectomy (LapPNx) hospital duration of stay (DOS). MATERIALS AND METHODS: We performed a retrospective review (design group) of all 726 patients (July 1997 to April 2004) who underwent LapNx or LapPNx at the Cleveland Clinic Foundation (CCF). Preoperative findings were recorded. Neural network algorithms were designed to predict the DOS before surgery. The models were then tested on a separate 252 patients from 6 different institutions, namely Tulane University Medical School, University of Arkansas for Medical Sciences, Cedars-Sinai Medical Center, University of Iowa, Mayo Clinic at Scottsdale and CCF. RESULTS: In the CCF design groups, the LapNx model accuracy was 73% to 74% and the LapPNx model 73% to 83%. Overall accuracy in the test groups at all 6 institutions was 72% (area under ROC 0.6 to 0.7) for the LapNx model and 52% to 81% (ROC 0.5 to 0.7) for the LapPNx model. CONCLUSIONS: The LapNx model provides 72% accuracy in predicting the DOS at all 6 institutions. The LapPNx model provided fair accuracy only at CCF and Tulane University Medical School. These models may streamline the delivery of care and continued testing will allow for further refinement.

Algorithms↗
PubMed2004

Laparoscopic dismembered pyeloureteroplasty: a single institution's 3-year experience.

PURPOSE: To review our most recent experience with laparoscopic dismembered pyeloureteroplasty (LDP) as treatment for ureteropelvic junction (UPJ) obstruction. PATIENTS AND METHODS: All patient charts from March 1, 2000, through March 1, 2003, were reviewed to identify individuals who had undergone LDP. Twenty-two consecutive procedures were performed on 21 patients. The average patient age was 37 years (range 6-77 years). Multiple data points were collected, including patient age, presenting symptoms, degree of hydronephrosis, presence of crossing vessels, operative time (cystoscopy, retrograde pyelography, stent placement, and LDP), estimated blood loss (EBL), length of hospital stay (time to discharge home after preoperative admission), parenteral analgesic use, complications, and results of follow-up imaging studies and symptoms (including an analog pain scale). Mean and range values for quantitative data are reported. RESULTS: Twelve right and ten left renal units were operated on; in 12 UPJs, a crossing vessel was causative of the obstruction. The mean operative time was 291 minutes (range 180-500 minutes) and the mean intraoperative EBL was 63 mL (range 20-100 mL). There were no conversions to open surgery. The mean hospital stay was 40 hours (range 24-120 hours). The average number of parenteral analgesic doses before conversion to oral narcotics was 5 (range 1-10). Three patients had successful pyelolithotomies at the time of reconstruction with a 100% stone-free rate on postoperative imaging studies. The average time of follow-up evaluation was 199 days (range 31-705 days). All patients either had serial ultrasound examinations, diuretic intravenous urograms, or both for follow-up evaluation, which demonstrated improvement in hydronephrosis and renal drainage. All patients with pain preoperatively had resolution of their symptoms postoperatively. There were no intraoperative complications, seven early postoperative complications (three urinary tract infections, two hospital readmissions for ileus, one urine leak, and one delayed hemorrhage, presumably from a trocar site). CONCLUSIONS: Laparoscopic dismembered pyeloureteroplasty is safe and effective and associated with minimal morbidity.

Adolescent↗
PubMed2003

Early experience with laparoscopic cryoablation in patients with small renal tumors and severe comorbidities.

PURPOSE: To present our preliminary experience with laparoscopic renal cryoablation in patients with small renal tumors and severe comorbidities. PATIENTS AND METHODS: Eight patients with a mean age of 75.6 years (range 68-82 years) who had small (mean 2.6+/-0.7-cm; range 1.4-3.8-cm) peripheral renal cortical lesions and significant comorbidities underwent laparoscopic cryoablation with a 3-mm cryoprobe. None of the patients was considered a good candidate for extirpative surgery. Tumors were biopsied prior to cryoablation. Intraoperative laparoscopic ultrasonography was utilized to confirm the tumor and to monitor the biopsy and the cryoablation process. RESULTS: Most patients had right-sided tumors, although there were no significant differences in the approach or outcome on this basis. Seven patients had intraoperative biopsies, and in all cases, good tissue samples were obtained. There were no intraoperative or postoperative complications. The average blood loss was 102.5+/-123.3 mL, and the mean operative time was 120+/-27.8 minutes. The mean hospital stay was 2.9+/-1.6 days. Postoperative imaging demonstrated defects consistent with ablation of the affected area; however, a residual nonenhancing mass defect usually was demonstrated. CONCLUSION: Laparoscopic cryoablation appears to be safe for the treatment of solid or complex renal masses in elderly patients with severe comorbidities. Further studies are necessary to determine the long-term efficacy before this modality can be considered an acceptable curative treatment for small renal cortical tumors.

Aged↗
PubMed2003

Endoscopic surgery for renal calculi.

PURPOSE OF REVIEW: Endoscopic surgery plays an important role in the treatment of renal calculi, especially for the more complex cases. Recent advancements have improved the efficacy of procedures, and increasing surgeon experience is associated with low complication rates. This article will review recent literature pertinent to endoscopic surgery for renal calculi. RECENT FINDINGS: Endoscopic renal calculus removal is associated with up to >90% calculus clearance rates. This is true for both retrograde and percutaneous approaches. The added utility of flexible instrumentation and holmium laser therapy have contributed greatly to improving surgical success. With increased experience in endoscopic techniques, major complications occur in approximately 1% of patients. Most procedures are performed on an outpatient (retrograde) basis or a <23 h inpatient (percutaneous) basis. SUMMARY: Endoscopic surgery is safe, and the most efficacious therapy with low morbidity for renal calculi.

Endoscopy↗
PubMed2002

Hand-assisted and conventional laparoscopic live donor nephrectomy: a comparison of two contemporary techniques.

BACKGROUND AND PURPOSE: Laparoscopic nephrectomy may make kidney donation more attractive. Modifications such as hand assistance may improve surgical outcomes. We compared our initial experience with hand-assisted laparoscopic nephrectomy with that of the conventional laparoscopic technique. PATIENTS AND METHODS: Two series of similar patients underwent conventional laparoscopic donor nephrectomy (LDN; N = 15) or hand-assisted laparoscopic donor nephrectomy (HLDN; N = 29). Operative time, warm ischemia time, estimated blood loss, complications, analgesic use, postoperative recovery, and serum creatinine concentration were compared. RESULTS: Open conversion was required in one HLDN patient because of intra-abdominal adhesions, and this patient was excluded from further analysis. The operative time, time to kidney extraction, and warm ischemia time were significantly shorter in the HLDN group, averaging 204.8 v 275.7 minutes, 173.4 v 239.3 minutes, and 2 minutes 21 seconds v 3 minutes 45 seconds, respectively. The intraoperative complication rates were 3.6% and 13.3%, respectively (P = 0.07). The postoperative complication rates were 6.8% and 6.7%. All grafts were functioning at the end of the study period, and there were no differences in rejection episodes, need for dialysis, complications, or nadir creatinine concentration according to the method of harvest. CONCLUSIONS: Hand-assisted laparoscopic donor nephrectomy provides shorter operative and warm ischemia times without a significant increase in donor morbidity.

Adult↗