Biomedical subjects

Jens-Uwe Stolzenburg

Publications and source records attributed to Jens-Uwe Stolzenburg.

At least 19 recordsLinked to original sources

PubMed2006

Anatomical landmarks of radical prostatecomy.

INTRODUCTION: In the present study, we review current literature and based on our experience, we present the anatomical landmarks of open and laparoscopic/endoscopic radical prostatectomy. METHODS: A thorough literature search was performed with the Medline database on the anatomy and the nomenclature of the structures surrounding the prostate gland. The correct handling of puboprostatic ligaments, external urethral sphincter, prostatic fascias and neurovascular bundle is necessary for avoiding malfunction of the urogenital system after radical prostatectomy. RESULTS: When evaluating new prostatectomy techniques, we should always take into account both clinical and final oncological outcomes. The present review adds further knowledge to the existing "postprostatectomy anatomical hazard" debate. It emphasizes upon the role of the puboprostatic ligaments and the course of the external urethral sphincter for urinary continence. When performing an intrafascial nerve sparing prostatectomy most urologists tend to approach as close to the prostatic capsula as possible, even though there is no concurrence regarding the nomenclature of the surrounding fascias and the course of the actual neurovascular bundles. After completion of an intrafascial technique the specimen does not contain any periprostatic tissue and thus the detection of pT3a disease is not feasible. This especially becomes problematic if the tumour reaches the resection margin. DISCUSSION: Nerve sparing open and laparoscopic radical prostatectomy should aim in maintaining sexual function, recuperating early continence after surgery, without hindering the final oncological outcome to the procedure. Despite the different approaches for radical prostatectomy the key for better results is the understanding of the anatomy of the bladder neck and the urethra.

Endoscopy↗

PubMed2006

Complications of endoscopic extraperitoneal radical prostatectomy (EERPE): prevention and management.

Endoscopic extraperitoneal radical prostatectomy (EERPE) is a further advancement of minimal invasive surgery as it overcomes the limitations of laparoscopic (transperitoneal) RPE by the strictly extraperitoneal route of access combining the advantages of minimal invasive surgery with the advantages of an extraperitoneal procedure. Endoscopic extraperitoneal radical prostatectomy has many advantages but is not without complications. The aim of this review article is to describe the most common complications of this procedure. Complications associated with endoscopic extraperitoneal radical prostatectomy are: vascular injury--bleeding--haematoma, bowel injury, lymphocele, injury to the bladder--ureter, port site hernia, anastomotic leakage--stricture, obturator nerve injury--paralysis, gas embolism, catheter blockage, and miscellaneous like perineal pain, pubic osteitis, infection- urosepsis. The present review paper focuses on the identification and management of these complications The incidence of most complications directly correlates with the surgeons' experience, and the various complications are related to technical errors rather than to the technique itself. The laparoscopist performing endoscopic/ laparoscopic radical prostatectomy should be aware of all these complications. He should be able to recognise promptly, treat efficiently, and ideally prevent these complications.

Endoscopy↗

PubMed2006

Application of paclitaxel-eluting metal mesh stents within the pig ureter: an experimental study.

OBJECTIVE: The purpose of the present study is to compare the standard bare metal stents (BMS) with the Paclitaxel-Drug Eluting Stent (DES) in the ureter of a pig model. MATERIALS AND METHODS: We report on an experimental study with ten female pigs weighing between 25 and 30 kg. The stents were randomly placed in either the right or left ureter in each of 10 study animals, for a total of 20 stented ureters. Ten ureters were stented with an R-Stent (Orbus Medical Technologies, Hoevelaken Netherlands), and ten with a Paclitaxel-Eluting Coronary Stent (Boston Scientific, Natick, MA, USA). Patency was measured by radiograph of the nephrostomy tract, intravenous urography and virtual endoscopy at 24 hours and 21 days after the initial procedure, respectively. RESULTS: Free flow of urine through the stents into the bladder was documented in all stented ureters 24 hours after stent insertion by radiograph of the nephrostomy tract. At the 21 day follow-up examination, 5 R-Stents were found to be completely occluded and two partially stenosed, whereas no occluded stent was detected in the Paclitaxel-DES group. Pathology examination of the stents at 21 days follow-up showed that the obstructed R-Stents generated severe inflammation with metaplasia of the urothelium. The Paclitaxel-Eluting MS generated a mild inflammatory response within the ureteral lumen at the site of the stent, without hindering ureteral patency. R-stents proved to develop more hyperplasia compared to the Paclitaxel-Eluting MS. CONCLUSIONS: Paclitaxel-DES, when compared with the standard R- Stent BMS, generated less inflammation and/or hyperplasia of the surrounding tissues, thus maintaining ureteral patency. Long-term animal trials are required to further validate our results.

Animals↗

PubMed2006

Cultured smooth muscle cells of the human vesical sphincter are more sensitive to histamine than are detrusor smooth muscle cells.

OBJECTIVES: To compare histamine receptor expression in cultured smooth muscle cells from the human detrusor and internal sphincter using receptor-specific agonists. METHODS: Smooth muscle cells from the bladder dome and internal sphincter were cultured from 5 male patients undergoing cystectomy for bladder cancer therapy. Calcium transients in cells stimulated with carbachol, histamine, histamine receptor 1 (H1R)-specific heptanecarboxamide (HTMT), dimaprit (H2R), and R-(alpha)-methylhistamine (H3R) were measured by calcium imaging. Histamine receptor proteins were detected by Western blot analysis and immunocytochemistry. RESULTS: H1R, H2R, and H3R expression was found in tissue and cultured cells. Carbachol stimulated equal numbers of detrusor and sphincter cells (60% and 51%, respectively). Histamine stimulated significantly more cells than carbachol in detrusor (100%) and sphincter (99.34%) cells. Calcium responses to carbachol in detrusor and sphincter cells were comparable and did not differ from those to histamine in detrusor cells. However, histamine and specific agonists stimulated more sphincter cells than did carbachol (P <0.001), and the calcium increase was greater in sphincter cells than in detrusor cells. Single cell analysis revealed comparable H2R responses in detrusor and sphincter cells, but H1R and H3R-mediated calcium reactions were significantly greater in sphincter cells. CONCLUSIONS: Histamine very effectively induces calcium release in smooth muscle cells. In sphincter cells, histamine is even more effective than carbachol regarding the number of reacting cells and the intracellular calcium increase. Some of the variability in the outcome of antihistaminic interstitial cystitis therapies might be caused by the ineffectiveness of the chosen antihistaminic or unintentional weakening of sphincteric function.

Calcium↗

PubMed2006

Histamine receptors in human detrusor smooth muscle cells: physiological properties and immunohistochemical representation of subtypes.

The potent inflammatory mediator histamine is released from activated mast cells in interstitial cystitis (IC). Here, we report on the histamine receptor subtypes involved in the intracellular calcium response of cultured smooth muscle cells (cSMC). Fura-2 was used to monitor the calcium response in cSMC, cultured from human detrusor biopsies. The distribution of histamine receptor subtypes was addressed by immunocytochemistry in situ and in vitro. Histamine stimulated a maximum of 92% of the cells (n=335), being more effective than carbachol (70%, n=920). HTMT (H1R-agonist), dimaprit (H2R) and MTH (H3R) lead to significant lower numbers of reacting cells (60, 48 and 54%). Histamine receptor immunoreactivity (H1R, H2R, H3R, H4R) was found in situ and in vitro. Histamine-induced calcium increase is mediated by distinct histamine receptors. Thus, pre-therapeutic evaluation of histamine receptor expression in IC patients may help to optimize therapy by using a patient-specific cocktail of subtype-specific histamine receptor antagonists.

Calcium↗

PubMed2006

Transperitoneal laparoscopic adrenalectomy: outline of the preoperative management, surgical approach, and outcome.

The laparoscopic approach to the adrenal gland has evolved to be the gold standard for most cases of adrenal conditions requiring surgical treatment. There is general consent about the safety, efficacy, and reproducibility of laparoscopic adrenal surgery. Compared to the open surgery, significant advantages with regard to shorter hospitalization time, decreased postoperative morbidity, improved cosmetics, and quicker convalescence are evident. The anatomic location of the adrenal gland led to the development of various approaches, including lateral transperitoneal, anterior transperitoneal, lateral retroperitoneal, posterior retroperitoneal, and even transthoracic approaches. The lateral transperitoneal approach is the technique most frequently used for laparoscopic adrenalectomy. A large operative field provides good orientation and visualization of familiar landmarks known from open surgery. In particular in the early learning curve this represents an advantage of the transperitoneal laparoscopic approach. This article describes in detail the indications, contraindications, preoperative evaluation, surgical technique, management of intraoperative complications, and outcome after lateral transperitoneal adrenalectomy.

Adrenal Gland Diseases↗

PubMed2006

Categorisation of complications of endoscopic extraperitoneal and laparoscopic transperitoneal radical prostatectomy.

The aim of the present review is to focus on the various attempts of categorisation of complications after endoscopic extraperitoneal and laparoscopic transperitoneal radical prostatectomy. Several classifications of complications and adverse events have been proposed in the literature but none is widely accepted or applied so far. We thus present a review of the existing literature and the complications of our series of 900 patients treated with endoscopic extraperitoneal radical prostatectomy (EERPE). We applied the recently revised Clavien classification system to grade EERPE complications.

Age Distribution↗

PubMed2006

Intrafascial nerve-sparing endoscopic extraperitoneal radical prostatectomy.

OBJECTIVES: To present a modification of our previously published technique of nerve-sparing endoscopic extraperitoneal radical prostatectomy (nsEERPE). METHODS: The technique enables puboprostatic ligament preservation, leaving intact the puboprostatic ligaments, endopelvic fascia, periprostatic fascia, and neurovascular bundles (intrafascial dissection). The modification of nsEERPE was performed in 50 consecutive patients. RESULTS: The total operative time was 131 minutes (range 75 to 165). The mean catheterization time was 5.4 days (range 5 to 14). CONCLUSIONS: The intrafascial nsEERPE is a modification of our previously published standard nsEERPE. The anterior approach to the periprostatic fascia enables less traumatic dissection from the prostate and thus, theoretically, a more viable neurovascular bundle.

Aged↗

PubMed2006

Histomorphology of canine urethral sphincter systems, including three-dimensional reconstruction and magnetic resonance imaging.

OBJECTIVES: To present a detailed anatomic description and comparison of the smooth and striated urethral sphincter in male and female dogs. We performed a thorough histologic evaluation, three-dimensional reconstruction, and magnetic resonance imaging of the lower urinary tract of male and female dogs. METHODS: The lower urinary tract anatomy was investigated in 16 male and 18 female dogs by serial sectioning, including immunohistochemical staining and three-dimensional reconstruction. Magnetic resonance imaging performed in 5 male and 5 female dogs before histologic investigation helped to demonstrate the anatomy in vivo. RESULTS: A urethral sphincter muscle in both sexes existed without muscular connection to the pelvic floor. It ran circularly and consisted of an inner smooth and outer striated muscular part. In the female dog, the striated muscle encircled the urethra and vagina in the caudal third of the membranous urethra (musculus urethrovaginalis). A urinary diaphragm (diaphragma urogenitale) could not be found histologically or by magnetic resonance imaging. CONCLUSIONS: The dog is a suitable animal model for investigations of the urethral sphincter. In the female dog, attention should be given to the special topography of the musculus urethrovaginalis.

Animals↗

PubMed2006

Case report: laparoscopic adrenalectomy in a patient with primary adrenal malignant melanoma.

We report a case of laparoscopic management of a primary malignant melanoma of the left adrenal gland. A 42-year-old male presented a 55 x 60-mm round, inhomogeneous, noninvasive mass of the left adrenal gland. Hormone-activity values were within normal range. The mass was removed laparoscopically en bloc along with the left adrenal gland, and its histopathologic evaluation was consistent with the features of a malignant melanocytic tumor. Postoperatively, the patient presented no signs of fever or remarkable blood loss and was discharged on the third day in good clinical condition. He is free of disease 1 year later.

Adrenal Gland Neoplasms↗

PubMed2006

Nerve-sparing endoscopic extraperitoneal radical prostatectomy: University of Leipzig technique.

PURPOSE: To describe the various operative steps as well as the functional and oncologic results of nerve-sparing endoscopic extraperitoneal radical prostatectomy (nsEERP). PATIENTS AND METHODS: One hundred twenty preoperatively potent patients have been treated with bilateral nsEERPE in our department. The average age of the patients was 60.3 years (range 41-74 years), and the mean prostate weight was 48.6 g (range 24-117 g). RESULTS: The mean operative time was 136 minutes (range 75-210 minutes). No conversions to open surgery were necessary. The mean catheterization time was 5.7 days (range 4-20 days). Lymphadenectomy was performed in 26 patients. The pathologic stages were pT2 in 78 and pT3 in 42 patients. Positive margins were detected in 7.7% (N = 6) and 19% (N = 8) of the patients with pT2 and pT3 disease, respectively. Erections sufficient for intercourse were reported in interviews with 58 patients (48.3%) during the 6-month follow-up period. Follow-up of at least 1 year is deemed necessary to draw more definite conclusions about erectile function. One week postoperatively, 32 patients (26.7%) required a maximum of 1 pad, 59 patients (49.2%) 2 or 3 pads, and 29 patients (24.2%) more than 3 pads per day because of incontinence, whereas 3 and 6 months after the procedure, 98 (82%) and 106 (88%) of the patients required a maximum of 1 pad, respectively. CONCLUSION: Our results demonstrate that nsEERPE can be performed with equal efficacy and preliminary results similar to those of standard open radical prostatectomy as well as transperitoneal laparoscopic prostatectomy while completely avoiding intraperitoneal complications.

Adult↗

PubMed2006

Role of laparoscopy for reconstructive urology.

PURPOSE OF REVIEW: Laparoscopic reconstructive urology is a challenging and technically demanding field of urology. As urologists' experience strengthened and technical modifications developed, urologic laparoscopy was applied in the treatment of malignancies and evolved from simple to technically demanding reconstructive techniques. This article reviews the latest published literature in the field of laparoscopic reconstructive urology and introduces our own persuasion for the role of this approach in urology. RECENT FINDINGS: Some laparoscopic procedures like orchidopexy, ureterolithotomy, pyelolithotomy and pyeloplasty require "a middle class level of laparoscopic skills" whereas other reconstructive techniques such as radical prostatectomy and cystectomy and partial nephrectomy are technically demanding and are still being developed with promising results. The reconstructive part of partial nephrectomy is small and refers to good hemostasis whereas in radical prostatectomy and cystectomy, the reconstructive part--urethrovesical anastomosis and urinary diversion, respectively--is an important factor, affecting the patient's postoperative quality of life. SUMMARY: The development of new instrumentation as well as the amelioration of urologists' laparoscopic skills will pave the way for the establishment of laparoscopic reconstructive urology in everyday practice. So far, laparoscopic reconstructive urology seems to be a well tolerated and effective treatment modality but still with not a completely clear role.

Humans↗

PubMed2006

Anaesthetic considerations for endoscopic extraperitoneal and laparoscopic transperitoneal radical prostatectomy.

We focus on the anaesthesiology and requirements for minimally invasive procedures for treating localized prostate cancer. The management of anaesthesia for laparoscopic and endoscopic radical prostatectomy (RP) can be more complex than expected. Numerous groups, especially early in their experience, have had problems (e.g. hypercarbia) with the anaesthesiology of the procedure. Co-operation between the surgeon and the anaesthesiologist is of paramount importance for a safe and effective laparoscopic or endoscopic RP. Nevertheless, the relative anaesthetic equipment and trained personnel should be available before embarking on such technically proficient procedures.

Anesthesia↗

PubMed2006

Quantitative immunohistochemical study of the innervation of the guinea-pig lower urinary tract.

OBJECTIVE: To study the innervation of the different muscle systems of the guinea-pig lower urinary tract, using immunohistochemical and enzyme histochemical methods. MATERIALS AND METHODS: Serial cryostat sections of both genders (four guinea-pigs each) were quantitatively analysed for cholinergic, adrenergic and peptidergic nerve fibre density using specific antibodies or enzyme histochemical labelling. Smooth muscle cell nuclei and varicosities or sectioned nerves were counted in detrusor, internal vesical sphincter (VS), ventral longitudinal musculature (VLM), and dorsal longitudinal musculature (DLM), and the ratios of nerves/nucleus (for detrusor, VLM and DLM) were evaluated statistically. The striated and the smooth external sphincter were examined qualitatively. RESULTS: Detrusor, VS, VLM and DLM had significantly different innervation patterns. In detrusor muscle parasympathetic nerve fibres dominated, while the VS and the urethral muscles had a major sympathetic nerve supply. Neuropeptide Y-positive nerve fibres were abundant in all of the muscles. CONCLUSIONS: Smooth muscles of the lower urinary tract of the guinea-pig are distinct muscular units with distinct innervation patterns. Although there are no corresponding studies in humans the general innervation seems to be equivalent in human and guinea-pig, qualifying the guinea-pig for comparative urological studies.

Animals↗

PubMed2005

Modular training for residents with no prior experience with open pelvic surgery in endoscopic extraperitoneal radical prostatectomy.

PURPOSE: To establish a teaching program for the performance of endoscopic extraperitoneal radical prostatectomy (EERPE) that would ascertain the safe and efficacious training of residents with no previous experience with open pelvic surgery. MATERIALS AND METHODS: The technique of EERPE was divided in 12 segments with 5 levels of difficulty. We thus designed a training program, where the resident learned the procedure in a mentor-defined schedule. During each educational EERPE, the trainee only performed the operative steps corresponding to his acquired skill level. The mentor performed the remaining parts of the EERPE, with the trainee assisting. The first 50 and consequent 100 cases performed by the residents were compared to the first 50 and last 100 cases (cases 521-621) performed by the mentor. RESULTS: Two residents with no prior experience with open pelvic surgery participated in the study, and required 43 and 38 procedures respectively, until they were considered to be competent. The initial 50 procedures performed completely independently by the residents had mean operative times of 176 and 173 minutes. There were 2 intraoperative rectal injuries (one patient developed recto-urethral fistula), and 1 hemorrhage, and 1 lymphocele, postoperatively. The positive margin rate for pT2 disease was 14.3 and 11.5%, and for pT3 tumors 38.8 and 29.1%, respectively. After an additional 100 procedures operated by the same residents, mean operative times were 142 and 146 minutes. There was one patient who needed a transfusion. Postoperative complications requiring re-intervention were 1 hemorrhage, 2 anastomotic leakages and 4 symptomatic lymphoceles. The positive margin rate for pT2 disease was 12.8% and 6.5%, and for pT3 tumors 33.3% and 26.3% respectively. No statistical significant differences were observed when comparing with the mentors cases. CONCLUSION: We have showed that residents with no prior experience in open surgery of the pelvis can adhere to the modular training scheme and successfully perform the EERPE procedure with similar risk of complications compared to the tutor.

Clinical Competence↗

PubMed2005

Nerve sparing endoscopic extraperitoneal radical prostatectomy--effect of puboprostatic ligament preservation on early continence and positive margins.

INTRODUCTION: A technical modification of nerve sparing endoscopic extraperitoneal radical prostatectomy (nsEERPE) with preservation of the puboprostatic ligaments is presented and compared to a previous technique. MATERIALS AND METHODS: nsEERPE was performed in 100 men with clinically localized adenocarcinoma of the prostate from March 2004 through February 2005. Patients were divided into two groups: Group A included patients in whom a standard nsEERPE was performed (n=50), and group B included patients in whom a puboprostatic ligament sparing nsEERPE was performed (n=50). The postoperative follow-up was 2 weeks and 3 months evaluating preliminary effects on early continence and positive margins. RESULTS: The early return to continence at 2 weeks postoperatively was achieved by 6 patients (12%) in group A, and 12 patients (24%) in group B. Three months after the procedure 24 (48%) and 38 (76%) patients were continent, in groups A and B respectively. Clinical outcome (early continence) was significantly better for Group B patients, at 2 weeks (chi-square test, p=0.0019) and at 3 months (chi-square test, p=0.0347) following surgery. No cases of complete or severe incontinence (more than 5 pads/day) were observed at 3 months after surgery, in either groups. Groups A and B did not exhibit significant differences regarding their histological status. In group A, positive margins were detected in 6.5% and 26.3% of patients with pT2 and pT3, respectively. In group B, positive margins were found in 3.2% and 15.8% of patients with pT2 and pT3, respectively CONCLUSION: We propose the use of puboprostatic ligament-sparing nsEERPE as an intriguing method to ascertain recuperation of early continence after nerve sparing procedures, without hindering the final oncological outcome.

Adenocarcinoma↗

PubMed2005

Endoscopic extraperitoneal radical prostatectomy in patients with prostate cancer and previous laparoscopic inguinal mesh placement for hernia repair.

INTRODUCTION: Since laparoscopic inguinal hernia repair has become a frequently performed surgical procedure, it is inevitable that patients who have been candidates for laparoscopic radical prostatectomy (LRP) may have had such prior intervention. The inguinal hernia repair might take the form of either total extraperitoneal hernioplasty (TEP) or transabdominal extraperitoneal hernioplasty (TAPP), with mesh placement. The objective was to show that performing endoscopic extraperitoneal radical prostatectomy (EERPE) in such patients was safe and feasible, and also to suggest modifications of the technique to facilitate the surgery. PATIENTS AND METHODS: There were no specific selection criteria and patients with prior mesh placements were encountered during the management of all consecutive patients undergoing EERPE. Modifications in the port placements were made to accommodate for previous mesh placements on the right and left side. The area of prior mesh placement was excluded from the dissection when creating the extraperitoneal space. The operation was performed, thereafter, using the standard EERPE method. RESULTS: Out of a total of 750 patients operated on with EERPE, 14 had prior TEP or TAPP with mesh placement. In both groups there were no differences found in the mean operative time. There were no major complications or reinterventions in patients with prior mesh placement. In each group (i.e. TEP and TAPP), a small bladder injury was diagnosed and managed intraoperatively with no further complication. One vascular injury to the inferior epigastric vessels was managed intraoperatively without significant blood loss. None of the 14 patients required blood transfusion. The mean catheterization time was 6.9 days. CONCLUSION: Although certain problems were presented by previous TEP/TAPP, it is nevertheless feasible to perform EERPE. By adapting port placements and surgical techniques the operation can be performed safely and with a good operative outcome.

Aged↗

PubMed2005

Mutations of BRAF and RAS are rare events in germ cell tumours.

The BRAF gene, one of the human isoforms of RAF, is activated by oncogenic Ras, leading to cooperative effects in cells responding to growth factor signals. Recently, somatic missense mutations in the BRAF gene have been detected in a variety of human tumors. We have studied male germ cell tumours (GCT) for probable mutations of the BRAF and Ras oncogene. Microsatellite instability (MSI) was analysed using mono- or di-nucleotide marker. Mutational analysis of 62 GCT (30 seminomas and 32 nonseminomas) was performed after microdissection of the different tumour components. The expression of Erk1/2, an important downstream point of convergence in the Ras-RAF-MEK-Erk pathway was assessed immunohistochemically. Activating BRAF missense mutations were identified in 3 out of 32 cases of nonseminomas (9%) but not in seminomas. The mutations were 1796T>A mutations and were found within the embryonic carcinoma component of these tumors. Two out of 30 seminomas (7%) and 3 out of 32 nonseminomas (9%) exhibited KRAS gene mutations. MSI was observed in 4 out 62 tumours (7%) [1 seminoma and 3 nonseminomas (embryonal carcinoma)]. All of the microsatellite instable embryonal carcinomas had a mutated BRAF gene. All 5 GCT with RAS mutations had an intact BRAF gene. We identified constitutively activated Erk in almost all tumours tested. Our data indicate that BRAF gene mutations are a rare event in GCT and are independent of KRAS mutations. In embryonal carcinomas, BRAF mutations may be linked to the proficiency of these tumours in repairing mismatched bases in DNA. The finding of activated Erk suggests a causative role for MAPK activation in GCT independent of activating BRAF or RAS mutations.

DNA Mutational Analysis↗