Biomedical subjects

Wolfgang Dorschner

Publications and source records attributed to Wolfgang Dorschner.

14 recordsLinked to original sources

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↗

PubMed2005

Impact of previous surgery on endoscopic extraperitoneal radical prostatectomy.

OBJECTIVES: To assess the impact of previous surgery on endoscopic extraperitoneal radical prostatectomy (EERPE). METHODS: A total of 500 patients who underwent EERPE for clinically localized prostate cancer between December 2001 and April 2004 were stratified into five groups: group 1, no previous abdominal, inguinal, or prostate surgery; group 2, previous upper abdominal surgery; group 3a, previous lower abdominal or pelvic surgery or open inguinal hernioplasty; group 3b, laparoscopic or endoscopic inguinal hernioplasty; group 4, previous prostate surgery; and group 5, a combination of groups 2, 3, and/or 4. Groups 1 and 2 were analyzed together, because the previous operative fields in group 2 were distant from the space of Retzius. The operative times, complications, and reinterventions were analyzed with the Mann-Whitney U test, chi-square test, and Fisher exact test. RESULTS: Of the 500 patients, 335 (67%) and 165 (33%) were in groups 1 and 2 and groups 3 to 5, respectively. The mean overall operative time was 149 +/- 30 minutes. Four patients (0.8%) required transfusions, with no conversion to open surgery and no mortality. A total of 90 complications (18%) and nine reinterventions (1.8%) occurred. EERPE was subjectively more demanding and challenging in patients with previous minimally invasive hernioplasty with mesh placement. No statistical significance was detected between the no=surgery (groups 1 and 2) and previous surgery (groups 3 to 5) patients in terms of overall operative time, positive surgical margin status, complications, or reinterventions. CONCLUSIONS: Endoscopic extraperitoneal radical prostatectomy is feasible in patients with various previous abdominal surgical procedures. Previous surgery did not seem to affect the overall operative time or complication or reintervention rate. Previous minimally invasive hernia repair with mesh placement made EERPE more demanding but was not a contraindication.

Abdomen↗

PubMed2005

Endoscopic extraperitoneal radical prostatectomy: oncological and functional results after 700 procedures.

PURPOSE: We review our experience with endoscopic (totally) extraperitoneal radical prostatectomy (EERPE) as first line therapy for localized prostate cancer. MATERIALS AND METHODS: A total of 700 consecutive patients underwent EERPE. Mean patient age was 63.4 years (range 42 to 77). Mean preoperative prostate specific antigen was 10.7 ng/ml (range 1.4 to 82). A total of 206 patients (29.4%) had a history of previous lower abdominal or pelvic surgery including inguinal hernioplasty with mesh placement and 43 patients (6.1%) had a history of prostatic intervention (transurethral resection of the prostate, high intensity focused ultrasound, Millin prostatectomy, radiotherapy). After preparation of the preperitoneal space the technique of EERPE duplicates the steps of classic open descending retropubic radical prostatectomy including a nerve sparing EERPE when indicated. RESULTS: Mean operative time was 151 minutes (range 50 to 320). There was no conversion and the transfusion rate was 0.9% in 6. Four patients (0.6%) had intraoperative rectal injuries which were treated endoscopically with a 2-layer suture. A total of 14 patients (2%) required early and 3 patients (0.4%) required late postoperative reintervention. Pathological stage was pT2a in 89 patients (12.7%), pT2b in 54 (7.7%), pT2c in 245 (35%), pT3a in 229 (32.7%), pT3b in 79 (11.2%) and pT4 in 4 patients (0.6%). Positive surgical margins were found in 10.8% (42 of 388) of patients with a pT2 tumor and in 31.2% (96 of 308) of patients with a pT3 tumor. Pelvic lymph node dissection was performed in 266 patients (38%), of whom 14 (5.3%) were found to have lymph node involvement. Mean catheterization time was 6.2 days. Six months after surgery 83.8% of the patients were completely continent, 10.4% needed 1 to 2 pads daily and 5.8% of patients needed more than 2 pads daily. Of all patients who underwent nerve sparing procedures, 100 patients had a postoperative followup of 6 months. Of the 66 patients with the unilateral nerve sparing approach 8 (12.1%) had erections sufficient for intercourse and 16 of 34 patients (47.1%) with the bilateral nerve sparing procedure had erections sufficient for intercourse with or without the help of phosphodiesterase type 5 inhibitors. CONCLUSIONS: The results of this series are promising. Perioperative morbidity is low, and short-term oncological and functional results are favorable. Although the followup is too short to draw definite conclusions, it is obvious that a nerve sparing approach in EERPE is feasible and reproducible. Our data demonstrate that EERPE can be performed with equal efficacy and results compared with laparoscopic transperitoneal radical prostatectomy, while providing the ease and safety of a totally extraperitoneal approach, completely avoiding intraperitoneal complications.

Adult↗

PubMed2005

Alterations in connexin expression in the bladder of patients with urge symptoms.

OBJECTIVE: To compare the formation of gap junctions between detrusor smooth muscle cells in situ and the distribution of connexin (Cx)40, Cx43 and Cx45 expressions in bladder biopsies from a control group (with bladder tumour) and from patients with urge symptoms, as smooth muscle cells of the human detrusor muscle communicate via gap junctions and express several connexin subtypes, alterations of which may be involved in the causes of lower urinary tract symptoms. MATERIALS AND METHODS: Connexin expression is prominent in myofibroblast-like cells, supposedly involved in afferent signalling pathways of the bladder. Their strategic position directly beneath the urothelium suggests they are a link between urothelial ATP signalling during bladder filling and afferent Adelta-fibre stimulation for co-ordination of bladder tonus and initialization of the micturition reflex. Modification of their coupling characteristics may have profound impact on bladder sensation. Bladder tissue probes of patients undergoing cystectomy or transurethral tumour resection for bladder cancer were used as controls. Tissue samples from patients with severe idiopathic urge symptoms were taken for exclusion diagnostics of interstitial cystitis (IC) and carcinoma in situ. The formation of functional syncytia between detrusor smooth muscle cells were examined in dye-coupling experiments by injecting with Lucifer Yellow. The morphology and structure of gap junctions were assessed by transmission electron microscopy and immunogold labelling of Cx43 and Cx45. The expression of connexin subtypes Cx40, Cx43 and Cx45 was compared by indirect immunofluorescence, and confocal laser scanning microscopy used for semiquantitative analysis. RESULTS: There was dye coupling between smooth muscle cells of the detrusor in situ. Electron microscopy and immunogold labelling showed very small gap junctional plaques. These findings were confirmed by confocal immunofluorescence. Semiquantitative analyses showed significantly higher Cx43 expression in the detrusor muscle, and a tendency to higher Cx45 expression in the suburothelial layer associated with urge symptoms, whereas Cx40 expression was unaffected. CONCLUSIONS: Smooth muscle cells of the human detrusor muscle are coupled by classical gap junctions, forming limited local functional syncytia. Both Cx43 and Cx45 are expressed at low levels in normal detrusor. Up-regulation of Cx43 in patients with urge incontinence supports the possibility of functional changes in the syncytial properties of detrusor smooth muscle cells in this condition. In addition, the observed increase of Cx45 in the myofibroblast cell layer supports the idea that alterations in sensory signalling are also involved. Comparison with previous reports implies that the pathophysiology of urgency is distinct from that of the unstable bladder and other forms of incontinence.

Aged↗

PubMed2004

Does the extraperitoneal laparoscopic approach improve the outcome of radical prostatectomy?

Laparoscopic radical prostatectomy (LRPE) became the operative procedure of choice for patients with clinically localized prostate cancer in selected urologic centers around the world. Principal advantages are the minimal invasive nature of the procedure, a superior visualization of the operative field because of the magnification of the optical system, an exact and watertight anastomosis, the possibility of early catheter removal, and a potentially reduced amount of blood loss. Recent data show that oncologic outcome is not compromised by the minimal invasive nature of the procedure. However, a major drawback of LRPE is the transperitoneal route of access to the extraperitoneal organ of the prostate. Therefore, principal disadvantages of LRPE are potential intraperitoneal complications. Endoscopic extraperitoneal radical prostatectomy is a further advancement of minimal invasive surgery because it overcomes the limitations of LRPE by the strictly extraperitoneal route of access, combining the advantages of minimal invasive surgery with the advantages of an extraperitoneal procedure. This article reviews the literature on minimally invasive (laparoscopic and endoscopic-extraperitoneal) radical prostatectomy.

Humans↗

PubMed2003

Evolution of endoscopic extraperitoneal radical prostatectomy (EERPE)--technical improvements and development of a nerve-sparing, potency-preserving approach.

During the last decade, laparoscopy has become a standard technique in the armoury of the urologist due to constant technological advances and refinements. Laparoscopic radical prostatectomy (LRPE), although technically demanding and associated with a considerable learning curve, has become the surgical procedure of choice in selected and specialized urological centers around the globe for patients with clinically localized prostate cancer. However, a major drawback of LRPE is the transperitoneal route of access to the extraperitoneal prostate. The principal disadvantages of LRPE are potential intraperitoneal complications, such as bowel injury, ileus, intraperitoneal bleeding, intraperitoneal urinary leakage, intraperitoneal adhesion formation and concomitant small bowel obstruction. Endoscopic extraperitoneal radical prostatectomy (EERPE) is a further advancement of minimal invasive surgery as it overcomes the limitations of LRPE by the strictly extraperitoneal route of access combining the advantages of minimal invasive surgery with those of an extraperitoneal procedure. Based on our growing experience with this procedure, we have introduced several technical modifications, improvements and refinements including a nerve-sparing, potency-preserving approach (nEERPE) in an effort to further improve this minimally invasive procedure.

Adult↗

PubMed2003

Hernia repair during endoscopic (laparoscopic) radical prostatectomy.

We retrospectively reviewed our experience in performing endoscopic extraperitoneal radical prostatectomy (EERPE) and totally extraperitoneal (TEP) hernia repair in one procedure to evaluate its feasibility and safety. Based on our experience of 70 laparoscopic radical prostatectomies, a total of 60 patients underwent EERPE. Eight of these had 10 hernias repaired with Prolene mesh. The median total operating time for EERPE was 165 minutes. Mesh placement required an additional 15 minutes for a unilateral hernia and 25 minutes for bilateral hernias. The conversion rate and the reoperation rate were 0%. The median duration of vesical catheterization was 8.3 days. One patient required a blood transfusion. The most common minor complications, occurring in eight patients, were edema and hematoma of the penis. No wound infection occurred. The only major complication was a deep venous thrombosis in one patient. No additional complications developed in the hernioplasty group. We conclude that the extraperitoneal approach for radical prostatectomy allows concomitant inguinal hernia repair with a low morbidity rate and within an acceptable operating time.

Aged↗

PubMed2003

Endoscopic extraperitoneal radical prostatectomy: initial experience after 70 procedures.

PURPOSE: After our initial experience with 70 transperitoneal laparoscopic radical prostatectomies we developed a totally extraperitoneal retropubic approach to radical prostatectomy using laparoscopic instruments. We report our initial experience with 70 endoscopic extraperitoneal radical prostatectomy procedures. MATERIALS AND METHODS: A total of 70 patients underwent endoscopic extraperitoneal radical prostatectomy. Mean patient age was 63.4 years (range 49 to 76). Mean preoperative prostate specific antigen was 12.48 ng./ml. (range 1.4 to 50.7). There were no specific selection criteria for the procedure. The steps of the procedure are preparation of the preperitoneal space with the help of a balloon trocar, trocar placement (a 3 x 5 and a 2 x 12 mm. port), pelvic lymph node dissection, exposure of the prostate and the bladder neck, incision of the endopelvic fascia, ligation of Santorini's plexus, bladder neck dissection, mobilization of the seminal vesicles, incision of Denonvilliers' fascia, sectioning of the prostatic pedicles with or without preservation of the neurovascular bundles, dissection of Santorini's plexus and apex, urethrovesical anastomosis with 7 to 9 interrupted sutures and removal of the specimen via an extraction bag. During the 70 endoscopic prostatectomies 11 hernia defects were treated in 9 patients concomitantly. RESULTS: There was no conversions and no re-interventions. Mean operative time was 155 minutes (range 90 to 260). One patient required transfusion with 2 units of blood cells. Pathological stage was pT2a in 19 patients, pT2b in 14, pT3a in 25, pT3b in 9 and pT4 in 3. Positive surgical margins were found in 2 of the 33 patients (6.1%) with pT2 tumors and in 13 of the 37 (35.1%) with pT3 and pT4 tumors. Postoperatively edema and hematoma of the penis in 10 cases was treated conservatively. Furthermore, 4 patients had asymptomatic lymphoceles, 1 required lymphocele drainage and 2 had partial obturator nerve paralysis, which resolved spontaneously. In 1 patient deep venous thrombosis developed. CONCLUSIONS: The preliminary results of this series are promising. Operative and perioperative morbidity was low. Functional results and oncological control were similar to the results of laparoscopic radical prostatectomy. The data demonstrate that endoscopic extraperitoneal radical prostatectomy can be performed with efficacy and results equal to those of laparoscopic radical prostatectomy, while providing the benefits of a totally extraperitoneal approach. Therefore, totally endoscopic extraperitoneal radical prostatectomy represents a technical improvement of laparoscopic technique because it completely obviates intra-abdominal complications and combines the advantages of minimally invasive laparoscopy and the retropubic open approach.

Aged↗

PubMed2002

Smooth muscle cells from human urinary bladder express connexin 43 in vivo and in vitro.

Smooth muscle cells (SMC) of the human urinary bladder are believed to be electrically coupled. However, it has not been successfully demonstrated the nature of the underlying cell-cell communication. Here, we used Western blot technique to demonstrate the gap junction protein connexin 43 (Cx 43) in human bladder musculature and in smooth muscle cell cultures. We found expression of Cx 43 in all samples of the detrusor (Mdv, n=6) and in five of six samples of the internal sphincter (Mv). Cx 43 expression was less in cell cultures, 60% showing Cx 43 expression. Iontophoretic application of the gap junction permeable fluorescent dye lucifer yellow revealed a mean of 2.6+/-2.2 (mean+/-SD, n=8) coupled cells in cultured smooth muscle cells. Our findings support the notion that Cx 43 is constitutively expressed in human bladder SMC in vivo. Thus, the function of the bladder is likely to be influenced by the organisation of smooth muscle cells into functional syncytia.

Aged↗

PubMed2002

Detrusor smooth muscle cells of the guinea-pig are functionally coupled via gap junctions in situ and in cell culture.

Intercellular communication between smooth muscle cells is crucial for contractile behaviour in normal and pathologically altered urinary bladder. Since the study of coupling is difficult in situ, we established cell cultures of bladder smooth muscle cells to analyse coupling mechanisms. Microinjection of Lucifer yellow demonstrated syncytia composed of only a few to several dozen cells. Electron-microscopic examination of freeze-fracture specimens and ultrathin sections revealed that the dye-coupling was based on typical gap junction formation between the cultured smooth muscle cells. Furthermore, we were able to demonstrate gap junctions within the tissue fragments from which the primary cultures were grown. By Western blotting, we found connexin-43-positive protein bands both in native tissue probes from the guinea-pig urinary bladder and in smooth muscle cell cultures. Extracellular electrical stimulation of single cells evoked calcium transients, as visualized by fura-2 ratiofluorimetry. Calcium waves propagated throughout the syncytia with a declining amplitude, showing that the calcium signal was not regenerative. Therefore, the calcium signal was probably transmitted by a diffusible factor. These findings correlated well with the dye-coupling that we found between detrusor smooth muscle cells in situ. The use of smooth muscle cell cultures therefore seems to be a feasible approach for studying coupling behaviour in vitro.

Animals↗

PubMed2002

The endoscopic extraperitoneal radical prostatectomy (EERPE): technique and initial experience.

Using the experiences of the extraperitoneal (endoscopic pelvic lymphadenectomy and inguinal hernia repair) and the transperitoneal approach (laparoscopic radical prostatectomy), we developed a totally extraperitoneal approach to endoscopic radical prostatectomy. In view of the favourable short-term outcome, we describe the technique of totally extraperitoneal endoscopic radical prostatectomy (EERPE) as a now standardised procedure. After creating the preperitoneal space by balloon dissection, five trocars were placed in the hypogastrium, allowing immediate access to the space of Retzius. The surgical technique of EERPE replicates the steps of the classical retropubic descending radical prostatectomy with slight modifications. The procedure starts with exposing the Retzius space and pelvic lymph node dissection. After that, the endopelvic fascia and the puboprostatic ligaments are incised, followed by ligating the Santorini plexus. The actual prostate dissection is similar to the open descending approach: bladder neck dissection, freeing of the seminal vesicles, transsectioning of the prostatic vesicles (with or without preserving the neurovascular bundles) and, finally, apical dissection. A water-tight urethrovesical anastomosis is performed with interrupted sutures. There were 20 patients who underwent EERPE. Mean operating time was 170 min with no conversion. No major complications occurred. Only one patient required a blood transfusion. The catheter could be removed on postoperative day 6 (n = 17) or on postoperative day 12 (n = 3). Final pathologic evaluations were 4 stage pT2a, 10 stage pT2b, 5 stage pT3a, and 1 pT3b. Surgical margins were negative in 17 patients. By avoiding entry into the peritoneal cavity, therefore, obviating intra-abdominal complications, such as bowel injury, ileus, or intestinal adhesions, the extraperitoneal endoscopic access provides a safe and minimally invasive approach to the prostate, combining the advantages of minimally invasive laparoscopy and retropubic open prostatectomy.

Adenocarcinoma↗

PubMed2002

Muscle systems of the lower urinary tract of the male rhesus monkey (Macaca mulatta): histomorphology and 3-dimensional reconstruction.

PURPOSE: The structure and function of the lower urinary tract are still a subject of controversial discussion. Experiments in various animals, including rhesus monkeys, are often performed to improve the understanding of human physiology without adequate knowledge of anatomical differences. Therefore, a detailed study of the lower urinary tract of the male rhesus monkey (Macaca mulatta) was performed to elucidate anatomical correspondences in rhesus monkeys and humans. MATERIALS AND METHODS: Lower urinary tract anatomy and histomorphology were investigated in male rhesus monkeys on serial sections. To differentiate striated and smooth muscle immunohistochemical staining was done. Three-dimensional reconstructions were developed to demonstrate the topography of the muscle systems. RESULTS: We identified certain systems, including detrusor musculature extending on the bladder neck, a ventral longitudinal muscle system of the bladder neck, continuation of the musculature of the ureters to the verumontanum, a urethral sphincter consisting of a striated and a smooth muscle part, musculature between the urethra and rectum, and a striated longitudinal muscle system ventral to the urethral sphincter. The prostate gland of the rhesus monkey does not encircle the urethra but is attached dorsolateral. The internal sphincter (musculus sphincter vesicae) of humans does not exist in the rhesus monkey. The longitudinal systems of the urethra differ significantly from those in humans. CONCLUSIONS: Due to significant differences in lower urinary tract anatomy the suitability of the male rhesus monkey seems limited as an animal model for humans. It is not suitable for studying the longitudinal muscle systems of the human bladder neck.

Animals↗

PubMed2002

Is the male dog comparable to human? A histological study of the muscle systems of the lower urinary tract.

Because of their superficial anatomical resemblance, the male dog seems to be suitable for studying the physiologic and pathological alterations of the bladder neck of human males. The present study was carried out to compare and contrast the muscular anatomy of the male dog lower urinary tract with that of humans. The complete lower urinary tract, including the surrounding organs (bulb of penis, prostate, rectum and musculature of the pelvic floor) were removed from adult and newborn male dogs and histologically processed using serial section technique. Based on our own histological investigations, three-dimensional (3D)-models of the anatomy of the lower urinary tract were constructed to depict the corresponding structures and the differences between the species. The results of this study confirm that the lower urinary tract of the male dog bears some anatomical resemblance (musculus detrusor vesicae, prostate, prostatic and membranous urethra) to man. As with human males, the two parts of the musculus sphincter urethrae (glaber and transversostriatus) are evident in the canine bladder neck. Nevertheless, considerable differences in formation of individual muscles should be noted. In male dogs, no separate anatomic entity can be identified as vesical or internal sphincter. The individual course of the ventral and lateral longitudinal musculature and of the circularly arranged smooth musculature of the urethra is different to that of humans. Differences in the anatomy of individual muscles of the bladder neck in the male dog and man suggest that physiological interpretations of urethral functions obtained in one species cannot be attributed without qualification to the other.

Animals↗

PubMed2002

Sphincteric musculature of female canine urethra in comparison to woman including 3D reconstruction.

The circular arranged sphincteric musculature of bladder neck of female dogs and women were studied histomorphologically. 3D reconstructions of the anatomy of the bladder neck improve the understanding of construction principles of the musculature of the lower urinary tract and help to compare both species. Our own investigations based on 12 adult female canine and 15 female human autopsy preparations. The special feature of our study was the extensive en bloc preparation of all the organs of the lower urinary tract and surrounding organs. The organ blocks were reprocessed in complete serial sections from the bladder outlet down to the bulb of vestibuli. Despite different detailed construction, in both species the striated sphincter musculature of the urethra is an independent morphological unit. There is no continuation of pelvic floor muscles to the urethra. In humans, the urethral sphincter consists of a smooth muscular part (m. sphincter urethrae glaber) and a striated part (m. sphincter urethrae transversostriatus). In the female dog, striated muscle fibres encircle the urethra in the middle third exclusively. In the distal third of the urethra, it encircles the urethra and the vagina. In the female dog, the lamellae of detrusor continue directly to the urethra. Throughout the cranial and middle third of the urethra, smooth muscle cell bundles form a homogenous compact sphincteric muscle originating from the middle circular layer of detrusor. In that way, no true bladder neck sphincter according to the m. sphincter vesicae in women exists in dogs. According to the smooth muscular part of the m. sphincter urethrae in women, for this musculature the term m. sphincter urethrae glaber is suggested. Despite a superficial resemblance, this study revealed a considerable difference of circular sphincteric muscle components between female dog and woman suggesting that functional studies in respect to urinary continence obtained in dogs cannot be attributed without qualification to humans.

Animals↗