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T Frede

Publications and source records attributed to T Frede.

At least 19 recordsLinked to original sources
PubMed2006

[Laparoscopic pelvic surgery: Where do we stand in the year 2006?].

Laparoscopic radical prostatectomy has become an equivalent alternative to the open retropubic approach, offering the advantages of minimally invasive surgery. It is being applied increasingly in Germany and the rest of Europe. Whether the surgical robot da Vinci will be used for this procedure to the same extent as in the United States is unpredictable because of high investment and maintenance costs. Similarly, laparoscopic sacrocolpopexy has proven to be a viable option compared to open transabdominal or transvaginal surgery, showing a significant reduction in postoperative morbidity. The value of radical cystectomy is controversial despite proven feasability. On one hand, the technical difficulties of purely laparoscopic urinary diversion result in very long operating times, and in the case of the laparoscopically assisted creation of a neobladder, the advantage of this approach has to be questioned. On the other hand, a maximum rate of 30% of local recurrences and distant metastases indicates at least poor patient selection. In conclusion, this procedure should be limited to a few experienced centers.

Cystectomy↗
PubMed2005

Robotics and telesurgery--an update on their position in laparoscopic radical prostatectomy.

Laparoscopy is handicapped by the reduction of the range of motion from six to only four degrees of freedom. In complicated cases (i.e. radical prostatectomy), there is often a crossing of the hands of surgeon and assistant. Finally, standard laparoscopes allow only 2D-vision. This has a major impact on technically difficult reconstructive procedures such as laparoscopic radical prostatectomy. Solutions include the understanding of the geometry of laparoscopy, but also newly developed surgical robots. During the last five years, there has been an increasing development and experience with robotics in urology. This article reviews the actual results focussing on the benefits and problems of robotics in laparoscopic radical prostatectomy. Own experiences with robot-assisted surgery include more than 1200 laparoscopic radical prostatectomies using a voice-controlled camera-arm (AESOP) as well as six telesurgical interventions with the da Vinci-system. Substantial experimental studies have been performed focussing on the geometry of laparoscopy and new training concepts such as perfused pelvitrainers and models for simulation of urethrovesical anastomosis. The recent literature on robotics in urology has been reviewed based on a MEDLINE/PUBMED research. The geometry of laparoscopy includes the angles between the instruments which have to be in a range of 25 degrees to 45 degrees ; the angles between the instrument and the working plane that should not exceed 55 degrees ; and the bi-planar angle between the shaft of the needle holder and the needle which has to be adapted according to the anatomical situation in range of 90 degrees to 110 degrees . 3-D-systems have not yet proved to be effective due to handling problems such as shutter glasses, video helmets or reduced brightness. At the moment, there are only two robotic surgical systems (AESOP, da Vinci) in clinical use, of which only the da Vinci provides stereovision and all six degrees of freedom (DOF). To date, more than 3000 laparoscopic radical prostatectomies have been performed worldwide at 92 centres with this system. The main advantage of the system represents the translation of open surgical skills to laparoscopy. Despite recent development of basic tools (e.g. bipolar forceps) for the da Vinci robot, investment and maintenance costs still represent the major problem of the device. Additionally, the device does not provide any haptic sense (i.e. tactile feedback). Robotic surgery represents a turning point of surgical research. However, broad use of robotic systems is limited mainly because of the high investment and running costs. Interestingly, more than in the field of cardiac surgery, there seems to be a need for telemanipulators in urology, mainly to reduce the learning curve of standard laparoscopy. However, new training concepts used in combination with mono-tasking computerized robots (AESOP) have proved their efficacy associated with a significant cost reduction.

Journal Article↗
PubMed2004

Transperitoneal laparoscopic radical prostatectomy: ascending technique.

BACKGROUND AND PURPOSE: To demonstrate the operative steps of transperitoneal laparoscopic radical prostatectomy with the ascending approach (Heilbronn technique). PATIENTS AND METHODS: The technique is based on our experience with more than 1000 cases of clinically localized prostate cancer from March 1999 to April 2004. The technical steps, instrumental requirements, patient data, complications, and reintervention rate were reviewed. RESULTS: The principles of the technique include the routine use of a voice-controlled robot (AESOP) for the camera, exposure of the prostatic apex with 120 degree retracting forceps, free-hand suturing for Santorini plexus control, application of 5-mm clips during the nerve-sparing technique, control of the prostatic pedicles by 12-mm Hem-o-Lock clips, the bladder neck-sparing technique in patients with stage T1c and T2a tumors, and use of interrupted sutures for the urethrovesical anastomosis. A considerable improvement was observed when comparing the first 300 with the most recent 300 cases (mean operating time 280 v 208 minutes; conversion rate 2.7% v 0.3%; reintervention rate 3.7% v 1.0%). CONCLUSIONS: Through our experience with more than 1000 cases, transperitoneal access for laparoscopic radical prostatectomy has proven to be feasible and transferable with results comparable to those of the original open approach. Besides the well-known advantages of minimally invasive surgery, the video endoscopic approach may offer further benefits in permitting optimization of the technique by video assessment.

Adult↗
PubMed2002

[Geometry of laparoscopy, telesurgery, training and telementoring].

Laparoscopic surgery in general is handicapped by the reduction of the range of motion from 6 to 4 degrees of freedom. This has a major impact on technically difficult procedures such as laparoscopic radical prostatectomy. Solutions for this problem include understanding the geometry of laparoscopy with sophisticated training programs, but also newly developed surgical robots, computer simulators, and telementoring. This article evaluates the value of these alternatives based on own experience and an analysis of the current literature. Our experience with robot-assisted surgery includes 244 laparoscopic radical prostatectomies using a voice-controlled camera arm (AESOP) and 6 telesurgical interventions with the da Vinci system. Additionally, experimental studies were performed focussing on the geometry of laparoscopy and new training concepts such as perfused pelvitrainers and computer simulation. Three-dimensional systems have not yet proved to be effective due to handling problems such as shutter glasses, video helmets, or reduced brightness. At present, there are only two robotic surgical systems (ZEUS, da Vinci) in clinical use for telesurgery, of which only the da Vinci provides stereovision and all 6 degrees of freedom (DOF). In the meantime, more than 100 laparoscopic radical prostatectomies have been performed with this system. However, there was no evidence of any advantages over the conventional laparoscopic approach. The ZEUS in combination with the telecommunication system SOKRATES is the only device that enables telemanipulation and telementoring over long distances (i.e., transatlantic). Robotic surgery represents a turning point in surgical research. However, broad use of robotic systems is limited mainly because of high investment and running costs. Whereas audiovisual telementoring will play a clear role in future training concepts, the need for telemanipulation or telesurgery has not yet been clarified.

Computer Simulation↗
PubMed2001

Retroperitoneal laparoscopic nephropexy.

Laparoscopic nephropexy is a suitable and clinically established procedure for the treatment of symptomatic nephroptosis. The availability of a minimally invasive therapy can facilitate decisions regarding the indication after careful selection of patients.

Adolescent↗
PubMed2001

Immunohistochemical determination of HER2 expression in breast cancer from core biopsy specimens: a reliable predictor of HER2 status of the whole tumor.

HER2 overexpression in breast cancer is associated with a poor prognosis, resistance to endocrine therapy and chemosensitivity to anthracyclines and paclitaxel. Moreover, trastuzumab (Herceptin) shows therapeutic benefit in patients with HER2 overexpressing tumors. Therefore, knowledge of the pretherapeutical HER2 status allows an optimal selection of patients for treatment. In addition to a definitive histological diagnosis, core biopsies of tumors offer the opportunity to evaluate the HER2 status preoperatively. In 64 patients with invasive breast cancer, sections of core biopsies and of the subsequently removed whole tumor were investigated immuno-histochemically with the DAKO HercepTest. Fifteen tumors (23%) revealed HER2 overexpression, and 44 tumors (69%) were negative in both, the core biopsy and the whole tumor sections. Two core biopsies were negative whereas the corresponding final specimen was 2+ positive. In 3 cases weak overexpression was observed in the core biopsy, but the whole tumor was negative. The overall concordance of the results achieved at core biopsy and whole tumor sections was 92% (kappa = 0.8). A negative HER2 result on core biopsy was never associated with a score 3+ tumor specimen nor was there a case of negative whole tumor specimen with a preceding 3+ score in the biopsy. If one demands the highest degree of overexpression (3+), 100% of our study patients would have been selected correctly using the results on core biopsy alone. We thus conclude, that the immunohistochemical investigation of core biopsies offers the opportunity for a valid preoperative estimation of HER2 overexpression.

Adult↗
PubMed2001

Ultrasound in endourology.

Ultrasonography was first used as a therapeutic aid in endourology in the early 1970s. Since that time, ultrasound has played an important role, and nowadays, interventional ultrasonography is an established procedure in urology. Procedures on the kidney, bladder, and prostate, which require different puncture techniques, are performed under ultrasound guidance. Today, extracorporeal shockwaves for the treatment of stones and Peyronie's disease are applied under ultrasonic control. Furthermore, high-intensity focused ultrasound (HIFU) is used experimentally for the treatment of renal tumors and, clinically, for the treatment of prostate cancer. In urologic emergencies, diagnostic and interventional ultrasonography is an important tool. Interventional ultrasound in urology has become an outstanding tool for the planning and performance of a variety of procedures, and every urologist should be able to use these technologies.

Biopsy, Needle↗
PubMed2001

Robotic and telesurgery: will they change our future?

In urology, at the end of the last millennium, there was an increasing use of computerized technology, extracorporeal shock wave lithotripsy, microwave therapy and high-energy focused ultrasound. However, experience with manipulating robots in urological surgery is still very limited. Laparoscopic surgery is handicapped by a reduction of the range of motion because of the fixed trocar position. The da Vinci system is the first surgical system to address all these problems adequately. The system consists of two main components: the surgeon's viewing and control console with three-dimensional imaging and the surgical arm unit that positions and manoeuvres detachable surgical instruments. The surgeon performs the procedure seated at the console holding specially designed instruments. Telerobotic laparoscopic radical prostatectomy provides advantages such as stereovision, dexterity and tremor filtering, but there is a learning curve with the device, mainly because of the magnification, the three-dimensional image and the lack of tactile feedback. However, after only a short period of time, the experienced surgeon is able to become familiar with the device. The impact of robotics in urological surgery is therefore very promising, and we are convinced that it will totally change the future of urological surgery.

Equipment Design↗
PubMed2001

Heilbronn laparoscopic radical prostatectomy. Technique and results after 100 cases.

INTRODUCTION: In 1999, Guillonneau and Vallancien presented a refined approach of a descending laparoscopic radical prostatectomy which based mainly on the primary access to the seminal vesicles and an improved suturing and knotting technique. Based on our own experience reconstructive laparoscopy as well as with open retropubic radical prostatectomy we have used a combined ascending/descending technique similar to open surgery. In this paper we want to describe our approach and to present the initial results with the Heilbronn technique. MATERIALS AND METHODS: A transperitoneal approach is used with a W-shaped arrangement of the trocars (13-mm umbilical port, 2 x 10 mm medial, 2 x 5 mm lateral ports). After the exposure of the Retzius' space and control of the dorsal vein complex the urethra is incised and the distal pedicles of the prostate (+/- the neurovascular bundle) are transsected. We now pull the apex ventrally and start with the incision at the bladder neck followed by a transvesical access to both vasa deferentia and seminal vesicles. The gland is entrapped in the Extraction Bag. After accomplishing the posterior wall of the urethrovesical anastomosis with five interrupted sutures, the foley catheter is placed into the bladder and the bladder neck is closed. Now the prostate is extracted via the umbilical incision. From March 1999 to June 2000, we have performed 100 cases (48 pT2-, 47 pT3- and 5 pT4 tumors). The mean preoperative PSA was 26.8 (1.4-75.5) ng/ml. Two tumors were grade 1, 72 grade 2 and 26 grade 3. Median Gleason score was 6 (3-9). All specimen were inked and examined according to the Stanford protocol. Postoperative continence was evaluated using a questionnaire monitored by a colleague who was involved in surgery. RESULTS: We had 5 conversions (rectal injury, difficult dissection, adhesion, 2x bleeding at the dorsal vein complex). The mean operating time was 278 (180-500) min., the transfusion rate 31%. One patient required reintervention due to bleeding from the right obturator fossa. 95% of the patients did not require any analgesia on the second postoperative day. Positive margins were found in 17% of the patients, of which 12 had a PSA nadir to a value of less than 0.1 ng/ml within 3 weeks after surgery. In 82 patients, the anastomosis was tight after removal of the catheter, median catheter time was 8 (6-30) days. 4% developed a stricture at the anastomotic site which could be treated by laser incision. On discharge 33% were continent, after 6 months 81%, whereas only 2 patients still suffer from grade II stress incontinence at 9 months. CONCLUSIONS: Laparoscopic radical prostatectomy is feasible but requires laparoscopic expertise. Its learning curve is still ongoing. Morbidity is low, oncological control is similar to results of open surgery, functional results are promising.

Aged↗
PubMed2001

Telesurgical laparoscopic radical prostatectomy. Initial experience.

INTRODUCTION: Telepresence surgery offers theoretically to overcome two main problems of laparoscopic surgery, i.e. the limitation to only four degrees of freedom and the lack of stereovision. Since 1998, telesurgical minimally invasive procedures have been performed with the da Vinci system mainly for cardiac bypass surgery. Clinical experience in urology is still very limited. We want to present our initial experience using the device for robot-assisted laparoscopic radical prostatectomy. MATERIAL AND METHODS: The Intuitive surgical system consists of two main components: the surgeon's viewing and control console with 3D imaging and the surgical arm unit that positions and maneuvers detachable surgical instruments. These instruments introduced via two 8-mm trocars allow movements in all 6 degrees of freedom due to the EndoWrist technology. The surgeon performs the procedure seated at the console holding specially designed instruments. Highly specialized computer software and mechanics transfer the surgeon's hand movements exactly to the microsurgical movements of the manipulators at the operative site. We have used a semilunar-shaped 5-trocar arrangement with the robot's arms at the lateral trocars and two assistant trocars medially. A sixth trocar was used in the right suprapubic area for retraction of the gland. The left assistant used different instruments such as bipolar forceps, Ultracision, Endoclip, whereas the right assistant mainly used the suction-irrigation device. Except the first case, the Intuitive System was attached after exposure of Retzius' space. RESULTS: We have treated 6 patients (2 pT2, 4 pT3, median Gleason score 6). The OR time averaged 315 (242-480) min including pelvic lymph node dissection. No intraoperative complications occurred, 1 patient required transfusions. There were no positive margins, median catheter time was 5 days. 3 patients were completely continent after 1 month. CONCLUSION: Telerobotic laparoscopic surgery offers several advantages over all presently available techniques, such as all six degrees of freedom, dexterity enhancement, tremor filtering, and stereovision. There is a learning curve with the device, mainly because of the magnification, the 3D image and the lack of tactile feedback. However, only after a short period of time, the experienced surgeon is able to get familiar with the device. However, there are still concerns with respect to the high investment and running costs of the device as well as regarding the necessity of further developments of instruments for urological procedures.

Aged↗
PubMed2000

Retroperitoneoscopic and laparoscopic suturing: tips and strategies for improving efficiency.

BACKGROUND: The difficulties of minimally invasive reconstructive surgery, laparoscopically or retroperitoneoscopically, are caused by spatial limitation and fixed trocar positions and, therefore, restricted movement and handling of the instruments. In addition to a standardization of the technique, continual training, and improved instrument technologies, optimization of the geometry of reconstructive surgery, such as angles and distances between the working ports or the camera and needle position, are imperative to providing an optimal clinical performance. MATERIALS AND METHODS: After designing a standardized suturing technique and conducting an experimental analysis of the geometric factors important in reconstructive surgery, we transferred these results to our clinical setting. A series of 116 reconstructive laparoscopic and retroperitoneoscopic procedures (nephropexy, pyeloplasty, bladder neck suspension, and radical prostatectomy) were analyzed according to the technical realization and quality of reconstruction. Trocar and table positions were adjusted according to our preliminary results, as were the position of the instruments and camera. RESULTS: The trocar and instrument positions are critical for the clinical outcome of reconstructive surgery. Continual training in a standardized suturing technique, together with the clinical application of the important geometric rules, can reduce surgery time by 50%. The time required for suturing single knots could be decreased even more: as much as 75%, thus ensuring efficient and safe reconstructive surgery. CONCLUSION: Reconstructive procedures such as pyeloplasty or radical prostatectomy can be standardized and performed in an acceptable amount of time with adequate quality when adhering to a standardized technique and the important geometric rules. Improved performance in terms of time and quality will increase the acceptance of these procedures, which can help to solve the problem associated with a low total number of indications for laparoscopy and retroperitoneoscopy.

Equipment Design↗
PubMed2000

Long-term experience with laparoscopic retroperitoneal lymph node dissection in the management of low-stage testis cancer.

OBJECTIVES: We describe our experience with laparoscopic retroperitoneal lymphadenectomy (LRLA) in 34 patients with low-stage germ cell tumors treated from 1992 to 1998. All patients had clinical stage-I disease with no clinical evidence (CT scan, ultrasound, tumor markers) of metastases. A laparoscopic dissection was used to assess the pathologic status of the relevant retroperitoneal lymph nodes. MATERIAL AND METHODS: 17 patients were treated by a transperitoneal laparoscopic approach, whereas in the last 17 patients retroperitoneoscopic retroperitoneal lymph node dissection was performed. The lymph node dissection was performed identically to open surgery with the modified template according to Weissbach including the paracaval, interaortocaval, upper pre-aortic, and right common iliac zonal nodes for right-sided tumors, and para-aortic, upper pre-aortic zones for left-sided tumors. Retrieval of the lymph node chains was accomplished using a small organ bag. RESULTS: The procedure could be completed successfully in 30 of 34 patients with stage-I disease. In these cases the mean duration of the procedure was 248 min. In 3 patients the lymphadenectomy was abandoned, because frozen section showed metastasis. In 1 case conversion to open surgery was necessary because of bleeding from the aorta. One patient developed a delayed ureteral stenosis which required operative repair. Three patients required temporary insertion of an indwelling ureteral stent, and another patient had a pulmonary embolism with an uneventful outcome. One patient with a LRLA on the right side later developed retrograde ejaculation. In 6 of the 33 patients (18%) embryonal carcinoma or mixed carcinoma was found. The postoperative hospital stay averaged 5.3 (3-9) days for the patients without complications or conversion to open surgery. After a median follow-up of 40 months no regional relapse occurred, but 2 patients developed pulmonary metastases which were treated successfully by three cycles of platinum-based chemotherapy. All patients have no evidence of disease. CONCLUSIONS: Our experience suggests that LRLA is a safe and accurate method for low-stage germ cell tumors with minimal invasiveness, but because of its technical difficulty it should be restricted to experienced centers.

Follow-Up Studies↗
PubMed1999

Geometry of laparoscopic suturing and knotting techniques.

BACKGROUND: Spatial limitation, together with a fixed trocar position, restricted handling, and movement of the instruments, is inevitably associated with reconstructive laparoscopy and retroperitoneoscopy. This problem includes not only suturing technique and instruments but also geometric factors of endoscopic reconstruction, such as optimal distances between the working trocars, length of instruments, and angles between the instruments and the object. We present an experimental access to determine the specific impact of these factors on reconstructive laparoscopy. MATERIALS AND METHODS: In an in vitro model, end-to-end anastomoses of porcine intestine were performed using a standardized intracorporeal suturing technique. Suturing was performed without and after training in reconstructive surgery with variation of the following geometric factors: (1) the distance between the working trocars (between 6 and 12 cm); (2) the position of the object (lateral right, medially, lateral left); (3) the camera position (medially, lateral right, lateral left); (4) the angle between the instruments and a horizontal line (15 degrees , 55 degrees, 90 degrees); (5) the intracorporeal length of instruments (between 10 and 25 cm); and (6) narrowed space available for the instruments (between 4 and 25 cm). RESULTS: Continual training decreased the time required for suturing between 30% to 50%. Training decreased the time required for nonsuturing activities between 50% and 70% but the time required for suturing activities only between 20% and 45%. If the space between instruments and camera was limited, shifting the camera into a lateral position simplified the procedure of intracorporeal suturing. Angles of <55 degrees between instruments and the horizontal line simplified laparoscopic suturing, as did angles of <45 degrees between the instruments. In cases of maximally narrowed space (diameter of 4 cm), a suture filament length of <10 cm decreased the time required by 30%. CONCLUSION: We suggest an isosceles triangle between the instruments with an angle between 25 degrees and 45 degrees and an angle of <55 degrees between the instruments and the horizontal line as the optimal geometry for intracorporeal suturing. These data should be considered when planning a reconstructive laparoscopic procedure (i.e., alignment of trocars, table position). However, further studies are required to confirm these preliminary results.

Anastomosis, Surgical↗
PubMed1999

Treatment of Peyronie's disease by extracorporeal shockwave therapy: evaluation of our preliminary results.

BACKGROUND: Peyronie's disease is an idiopathic disorder of the penis that produces erectile dysfunction. It affects mainly the tunica albuginea. We describe our preliminary results with extracorporal shockwave therapy (ESWT) as a new noninvasive modality for the treatment of Peyronie's disease. PATIENTS AND METHODS: In this study, 24 patients aged 36 to 67 years were treated with ESWT on the Lithostar overhead-module (Siemens). All our patients had unsuccessful medical treatment before ESWT. The average plaque was 7x15 mm. The number of shockwaves ranged from 15,000 to 25,000 (18-21 kV) delivered in four to ten sessions. Most patients needed local anesthesia before therapy. RESULTS: Four patients (17%) showed marked improvement and complete remission of the penile deviation. Six patients (25%) showed partial remission with painless erections after treatment. Four patients had painless erections after treatment but still had some penile deviation. In 10 patients (41%), ESWT failed, necessitating subsequent penile surgery. CONCLUSIONS: Our preliminary results with a response rate of 59% with ESWT for Peyronie's disease, including a 17% complete remission rate, is encouraging. However, further multicenter studies will have to prove if ESWT is a real therapeutic option for this disease.

Adult↗
PubMed1999

Complications of laparoscopic procedures in urology: experience with 2,407 procedures at 4 German centers.

PURPOSE: The 4 most active centers of the laparoscopy working group of the German Urologic Association collected data about the complications associated with laparoscopic surgery in urology. MATERIALS AND METHODS: At 4 centers 2,407 laparoscopies or retroperitoneoscopies were performed as of May 1998, including 776 for varicocelectomy, 259 for cryptorchidism, 481 for pelvic lymph node dissection, 351 for nephrectomy/heminephrectomy renal pathology, 139 for renal cyst resection, 58 for ureteral procedures, 44 for adrenalectomy, 41 for nephropexy, 41 for lymphocele fenestration, 40 for retroperitoneal para-aortic lymphadenectomy and 187 for other operations. The complications were evaluated, listed according to the anatomical specificity and grouped with respect to the surgical step during laparoscopy. RESULTS: A total of 107 complications (4.4%) occurred. The re-intervention rate was 0.8% and the mortality rate was 0.08%. The complication rate depended on the difficulty of the procedure and averaged 1.0, 3.9 and 9.2%, respectively, for easy, difficult and very difficult operations. The majority were vascular injuries (1.7%) and visceral lesions (1.1%) followed by complications of healing and infection (0.8%). Only 0.2% of complications was associated with the access technique (trocar insertion), whereas most occurred during dissection (2.9%). The complication rate was 13.3% for the first 100 procedures and subsequently averaged 3.6%. CONCLUSIONS: Critical documentation of experience from several institutions, especially for an analysis of complications of urological laparoscopy, is important for the development of this surgical technique. The overall complication rate is comparable to other specialties. Future technical developments in trocar insertion, tissue dissection and control of bleeding with our improved training program will further reduce the complication rate.

Germany↗
PubMed1998

[Retroperitoneoscopy--experiences with the first cases].

UNLABELLED: A retroperitoneal access is most commonly applied for open procedures in urology. With introduction of the balloon dissecting technique, this anatomical route could also be used for laparoscopic surgery. MATERIALS AND METHODS: From 12/1992 to 10/1997, a total of 200 retroperitoneoscopic procedures have been performed in 197 patients (age 4-82 years): 78 nephrectomies, 50 renal cyst resections, 14 nephropexies, 11 ureterolyses, 8 retroperitoneal lymph-node dissections, 8 renal biopsies, 6 adrenalectomies, 6 heminephrectomies, 6 pyeloplasties, 5 ureterolithotomies, 6 ureterocutaneostomies and 2 others. Thirty-eight patients (19%) had undergone previous abdominal surgery; 22 (11%) had had kidney and ureter operations. Dissection of the retroperitoneal space was done with a balloon catheter in 14 or a balloon trocar system in 93 cases, and in the last 93 patients digital dissection with the index finger proved to be sufficient. RESULTS: We classified 76 as simple (i.e., renal biopsy, renal cyst resections, ureterocutaneostomy) and 102 as difficult (i.e. adrenalectomy, nephrectomy, nephropexy) and 22 (11%) as very difficult operations (i.e., pyeloplasty, heminephrectomy, lymphadenectomy). There has been a significant learning curve during the first 50 cases as reflected by increased operating time and complications and the conversion rate to open surgery. After that, the OR times mainly depended on the difficulty of the procedure, averaging 45-100 min for an easy retroperitoneoscopy, 95-185 min for a difficult and 185-240 min for a very difficult operation. In the last 50 cases, the complications, conversion and reintervention rate have become comparable to open surgery (2, 4 and 2%). CONCLUSIONS: After more than 200 cases of retroperitoneoscopy, the access technique has been significantly simplified. The procedure is standardized, safe and reproducible.

Adolescent↗
PubMed1998

Three-dimensional computed tomography of the reconstructed lower urinary tract: technique and findings.

The aim of this pilot study in 54 patients was to improve the visualization of the anatomy and postoperative changes in the pelvic topography after bilateral ureteroileal urethrostomy, using surface rendering of electron beam CT (EBCT) data for the 3D display. Fifty-four patients (39 men and 15 women) were scanned with an EBCT unit between 3 and 110 months after performing orthotopic ureteroileal urethrostomy ("Hemi-Kock") or ureteroileal rectosigmoidostomy. Various parameters and spatial viewing points were used in the 3D reconstruction, which was performed interactively on external workstations with commercially available software. The anti-reflux nipple was visualized as a distinct structure in all patients. In 8 patients with an interval of more than 12 months between surgery and CT, the pouch had developed an ovoid shape almost indistinguishable from the original bladder. The segmented data sets were partly animated to display the anatomy as virtual endoscopy. Three-dimensional depiction and virtual endoscopy of the neobladder using EBCT are a new way of imaging the postoperative anatomy. Its clinical efficacy in the diagnosis of inconclusive postoperative morbidity, especially voiding problems, and planning of necessary therapy have to be the subject of further evaluation.

Adult↗