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Biomedical subjects

W Hohenberger

Publications and source records attributed to W Hohenberger.

At least 19 recordsLinked to original sources

Curative in situ ablation of colorectal liver metastases-experimental and clinical implementation.

INTRODUCTION: In situ ablation of colorectal liver metastases is frequently assessed for palliative treatment only. The establishment of clinically relevant lesion size and a lack of long-term survival data were regarded as main limitations to using them with curative intention. In contrast to surgical liver resection, whose oncological findings seem to have remained unchanged over the years, the in situ ablation methods have considerably changed technically and clinically in the last few years. OBJECTIVE: The aim of the paper was to point out experimental and clinical data underlining the impact of in situ ablation for potentially curative treatment of colorectal liver metastases. DISCUSSION: On the basis of experimental data, the aim of complete local tumor control (R0 ablation) can only be obtained if additional energy is applied after reaching the tumor-adapted maximal coagulation volume. Analogous to the oncological safety margin in surgical resection, we defined this decisive energy difference as the "energy safety margin" for in situ ablation. The energy safety margin is the energy that must be additionally applied after reaching the plateau in the energy/volume curve to achieve complete tumor coagulation. In addition to that, in situ ablation should be combined with temporary interruption of hepatic perfusion whenever possible to prevent intralesional recurrences. In this way, the thermoprotective mechanism of hepatic perfusion can be effectively eliminated. With restrictions, the survival data after ablation in specialized centers is comparable to surgical resection with concomitantly lower morbidity and mortality. Based on recent findings and with the corresponding expertise in the field of ablation and state-of-the-art equipment, ablation is, thus, an alternative to surgical resection. The combined application of surgical resection and ablation is also a suitable method for increasing the R0 rate and thus helps improve the prognosis of treated patients. In summary, it can be said that in situ ablation is a useful expansion of the therapeutic spectrum of liver metastases and can be applied as an alternative to or in combination with surgical resection.

Animals↗

Histological response of peritoneal carcinomatosis after hyperthermic intraperitoneal chemoperfusion (HIPEC) in experimental investigations.

BACKGROUND: In selected patients with peritoneal carcinomatosis from colorectal cancer prognosis can be improved by hyperthermic intraperitoneal chemotherapy (HIPEC) after cytoreductive surgery. The aim of this study was to evaluate the tumor response of peritoneal carcinomatosis in tumor-bearing rats treated with HIPEC. METHODS: CC531 colon carcinoma (2,5 x 106 cells), implanted intraperitoneally in Wag/Rija rats, was treated by hyperthermic intraperitoneal chemotherapy. After 10 days of tumor growth the animals were randomized into five groups of six animals each: group I: control (n = 6), group II: sham operated animals (n = 6), group III: hyperthermic intraperitoneal perfusion (HIP) without cytostatic drugs, group IV: HIPEC with mitomycin C in a concentration of 15 mg/m2 (n = 6), group V: mitomycin C i.p. alone in a concentration of 10 mg/m2 (n = 6). After 10 days the extent of tumor spread and histological outcome were analysed by autopsy. RESULTS: All control animals developed extensive intraperitoneal tumor growth. Histological tumor load was significantly reduced in group III and group V and was lowest in group IV. In group II tumor load was significantly higher than in group I. Implanted metastases were significantly decreased in group IV compared with group I and group II. CONCLUSION: These findings indicate that HIPEC is an effective treatment for peritoneal carcinomatosis in this animal model. HIPEC reduced macroscopic and microscopic intraperitoneal tumor spread.

Adenocarcinoma↗

Cerebral representation of the anorectum using functional magnetic resonance imaging.

BACKGROUND: Anorectal continence depends not only on the organs of continence but also on cerebral control. There are relatively few data regarding cerebral processing of anorectal continence. METHODS: Thirteen healthy subjects underwent rectal distension to cause urge increasing to discomfort during functional magnetic resonance imaging (fMRI). In addition, a painful heat stimulus was applied to the skin of the anterior abdominal wall in the dermatome corresponding to the rectum. Voluntary contraction of the anal sphincter was also performed. Subjective rating of stimulus intensity was recorded. Evaluation of the data used a general linear model with Brain Voyager(trade mark). RESULTS: Subjective sensation of discomfort increased during repeated rectal distension and caused activation in the anterior cingulate gyrus, insula, thalamus and secondary somatosensory cortex seen on fMRI. Perception of rectal urge and discomfort activated the same cerebral regions with differing intensity. Application of a painful thermal stimulus in the corresponding dermatome showed a modification of the response. Voluntary contraction of the anal sphincter led to activation of the motor cortex and increased activity in the supplementary motor cortex and the insula. CONCLUSION: Cerebral representation of the anorectum as mapped by fMRI is intricate and reflects the complexity of the continence mechanism.

Adult↗

The influence of abdomino-peranal (intersphincteric) resection of lower third rectal carcinoma on the rates of sphincter preservation and locoregional recurrence.

OBJECTIVE: The most extended form of rectal resection, representing the very last option for sphincter preservation is abdomino-peranal intersphincteric resection for tumours of the lower third which otherwise would not be resectable with preservation of the sphincter by an abdominal approach alone. PATIENTS AND METHODS: The data of 476 patients with a carcinoma in the lower third of the rectum who underwent primary treatment for stage I-III disease by low anterior resection, abdomino-peranal (intersphincteric) resection or abdominoperineal excision between 1985 and 2001 were analysed. The time periods 1985-94 and 1995-2001 were compared. RESULTS: The rate of intersphincteric resections increased from 3% in 1985-94 to 27% in 1995-2001 while abdominoperineal excisions decreased. Postoperative complication rate was not increased in intersphincteric resections (25%) while postoperative mortality did not differ between the operative procedures. The overall 5-year-rate of locoregional recurrence decreased from 18% to 16%. In intersphincteric resections 14.2% of the patients treated with radiochemotherapy developed locoregional recurrence, while this rate was 46.5% (7/18) if adjuvant treatment was not administered (P = 0.0200). The cancer-related 5-year survival rate was not altered by intersphincteric resection. CONCLUSION: In carcinomas of the lower third of the rectum, the application of abdomino-peranal intersphincteric resection can reduce the need for rectal excision by 20%. Neo-/adjuvant radiochemotherapy is required to reduce locoregional recurrence to an acceptable level.

Adult↗

Multimedia article. Laparoscopic restorative proctocolectomy for ulcerative colitis.

BACKGROUND: With increasing experience, laparoscopic techniques have been applied even to extended colorectal operations as restorative proctocolectomy for ulcerative colitis and familial adenomatous polyposis. METHODS: A 36-year-old woman with a 7-year history of ulcerative colitis was transferred for elective surgery 6 weeks after an episode of toxic megacolon treated conservatively. The procedure was performed in modified lithotomy position using six trocars. After initial medial transection of the three main vascular pedicles of the ileocolic and middle colic vessels and the inferior mesenteric artery and vein, the colon was dissected free laterally, from the sigmoid orally toward the ileum. Special consideration was necessary for dissection of the omentum. The rectum was mobilized down to the pelvic floor in two steps, starting at the level of the promontory and the upper rectal stalks. It was transected at the level of the dentate line. Through a Pfannenstiel incision, the bowel was extracted. After transection of the ileum and removal of the specimen, a J-pouch was created. The anastomosis was completed laparoscopically using a double-stapling technique. Finally, a diverting loop ileostomy was created. RESULTS: A total of 13 patients underwent surgery. The medium age of these patients was 25.5 years (range, 19-57 years). There was no conversion to an open procedure. The median length of hospital stay was 11.5 days (range, 7-107 days). Four patients experienced major complications, including one case each of pouch failure after arterial occlusion, pouch-vaginal fistula, infected hematoma, and intraabdominal abscess formation. There was no postoperative mortality. CONCLUSIONS: For restorative proctocolectomy, laparoscopic techniques proved to be safe and feasible. With further experience, they may have the potential to become an appealing alternative to open surgery.

Adult↗

Hyperthermic isolated limb perfusion (HILP) in malignant melanoma. Experience with 101 patients.

AIMS: To analyse results with a standardized HILP procedure in terms of response rate, recurrence pattern and complication rate. PATIENTS AND METHODS: From 1992 to 2003 HILP with melphalan and dactinomycin was performed in 101 patients with loco-regional metastases of malignant melanoma of the limbs. Among these were 66 women and 35 men with a median age of 62 years. Forty patients were in M. D. Anderson stage IIIA, 51 patients in stage IIIAB and 9 had stage IV disease at the time of perfusion. If not been done before, regional lymph node dissection preceded limb perfusion in the same setting. RESULTS: A complete response (CR) was observed in 58 out of 87 evaluable patients. Twenty-one patients achieved a partial response (PR) and eight patients were non-responders. The overall response rate was 90.8%. The median recurrence-free interval after CR was 21 months. Severe toxicity (Wieberdink IV/V) was observed in five patients necessitating fasciotomy in four of them and above knee amputation in one patient. All further cases presented with grade II-III toxicity. The overall survival was 42 months, with a 5-year survival rate of 38%. Survival significantly differed according to stage of disease. CONCLUSION: HILP is an effective treatment for loco-regional tumour relapse of malignant melanoma of the extremities and has improved by modification of technique. In the absence of regional lymph node and distant metastases long-term survival can be achieved in responders.

Adult↗

Effect of orthotopic small bowel transplantation on mineral metabolism in an experimental model.

BACKGROUND: Numerous experimental models have been described for investigation of short bowel syndrome. The aim of this study was to examine the effect of orthotopic small bowel transplantation (OSBT) on universal metabolism in an inbred rat model, with particular emphasis on mineral metabolism. METHODS: Jejunoileal resection and syngeneic OSBT was performed in 12-week-old male Lewis rats. Metabolic studies were performed over the following 16 weeks. Bones were analysed by physicochemical methods, dual X-ray absorptiometry, biomechanical procedures and histomorphometry. Biochemical markers of bone turnover were also measured. RESULTS: Jejunoileal resection induced severe short bowel syndrome with profoundly reduced food efficiency, bone size, fracturing energy and bone mineral content, but no cancellous bone osteopenia. After OSBT rats showed normal growth; bones were of normal size, and bone mineral content and fracturing energy were similar to those in sham-operated controls. However, tibial, but not vertebral, cancellous bone osteopenia was found after transplantation. CONCLUSION: OSBT with portal venous drainage achieves almost optimal mineral and bone metabolism. In the absence of immunosuppressive therapy, OSBT does not appear to have major untoward side-effects on bone in rats.

Anastomosis, Surgical↗

Laparoscopic TME-the surgeon's or the patient's preference.

Since laparoscopic surgery in rectal cancer was introduced ten years ago large patient collectives have been published by several authors in the meantime. The literature was carefully reviewed to analyse data on postoperative complications, long term prognosis and quality of life after laparoscopic surgery for rectal cancer to answer the question whether laparoscopic surgery is still just feasible or maybe has even reached the golden standard. The review showed that there is not a single prospectively randomized trial published comparing laparoscopic vs. open surgery for rectal cancer. It is clearly evident that until now the most laparoscopic series are published with patients selected according to criteria that vary significantly especially regarding the kind of procedures performed (anterior, low anterior, intersphincteric resections and abdomino-perineal excision), other demographic items like gender, body mass index, eventual prior laparotomies, emergencies and tumor related characteristics like tumor stage or T-categories. At the moment any data concerning outcome from prospectively randomized trials comparing laparoscopic versus open surgery for rectal cancer are missing. Therefore, there is more speculation and belief concerning the true quality of laparoscopic surgery. The review in the literature only indicates, that laparoscopic surgery for rectal cancer is feasible. To prove the potential advantage of laparoscopic surgery in rectal cancer randomized trials are essential. If a surgeon discusses laparoscopic surgery outside a randomized trial, he should go through a questionnaire, presented in the paper which reflects the present situation without any proven advantage and not available long term results and should leave a final decision to the patient.

Digestive System Surgical Procedures↗

[Inspection jejunostomy after complex reconstruction of the central bile duct. Indication, description, and personal experience].

INTRODUCTION: A modified Roux-en-Y hepaticojejunostomy that allows postoperative endoscopic access was first described in 1984. We report our experience with this operative procedure. METHODS: After complicated bile duct resection, reconstruction was performed as a modified Roux-en-Y hepaticojejunostomy, with the 20 cm afferent limb brought up as in terminal jejunostomy in the right upper abdominal quadrant. Postoperative follow-up consisted of endoscopic and radiologic control of the biliary tree every 3 months for 1 year; ileostomy resection was performed 1 year later if the postoperative course was undisturbed. RESULTS: From March 1995 to February 2002, we performed this operation in 17 patients (mean age 56 years). The endoscopic and radiologic (cholangiography) diagnostic procedures--every 3 months postoperatively--were uneventful. CONCLUSIONS: The modified Roux-en-Y hepaticojejunostomy described here permits good control and intervention in complicated surgery for bile duct lesions, tumor resection with unclear resectional margins, and recurrent intrahepatic stone formation.

Adult↗

Neoadjuvant chemotherapy does not increase postoperative complication rate after resection of colorectal liver metastases.

BACKGROUND: This paper discusses, whether neoadjuvant chemotherapy has an impact on the rate of postoperative complications after primary resection of liver metastases from colorectal carcinoma. METHODS: Of 183 patients 64 were studied. The patients were subdivided into two matched groups of 32 patients each-prior neoadjuvant chemotherapy (CT-group) vs. (control-group, primary resection). RESULTS: There were no postoperative complications in 24 patients of the control group (75%) and 26 patients of the CT-group (81%). Following prior chemotherapy, no major complications such as liver failure were observed, even after extended resections. CONCLUSION: Neoadjuvant chemotherapy prior to surgical resection of colorectal liver metastases does not result in an increase of postoperative morbidity and mortality.

Adult↗

["Erlangen broncho-trainer" -- newly developed training model with physiological ventilation for interventional bronchoscopy].

BACKGROUND: Biosimulation models have proved their value in numerous training courses for endoscopic procedures and play an important role in education and further training, as well as in the introduction of new techniques. In the field of interventional bronchoscopy, the level of realism is increased when biological lung tissue is available not only in a collapsed state, but also with physiological expansion. METHODS/RESULTS: A new modification of the well-known Erlangen Endo-Trainer has been developed, involving a transparent cover that provides airtight closure of the thoracic cavity. An integrated vacuum pump creates low pressure in the interior of the model. This allows a training lung from the pig to be fully expanded and "physiologically ventilated", with adjustable intermittent inspiration and expiration phases. The breathing and completely expandable biological training lung from the pig not only provides better anatomical orientation thanks to the lung's full three-dimensional expansion, but with the convincing and realistic quality of the tissue it also provides a good practice facility for various types of bronchoscopic intervention. CONCLUSIONS: In an initial training course, the new system successfully allowed various diagnostic techniques to be practiced, such as bronchoalveolar lavage (BAL), transbronchial needle aspiration (TBNA), and peripheral forceps biopsies with transillumination guidance and interventional techniques such as foreign-body removal and electrocautery as well. These initial positive results are also encouraging for the future provision of training facilities in additional interventional techniques.

Bezoars↗

Training in GI endoscopy: can we objectively predict the performance of trainees? A prospective correlation study.

BACKGROUND: No objective criteria have hitherto been available for assessing the individual talents and skills of trainees involved in GI endoscopy. The aim of our study was to compare the correlation of various psychological, psychomotor and cognitive tests (psy-tests) and of the subjective assessment of the trainer (expert assessment) at the beginning of the training with the objective performance of the trainees at the end of a one-week training period in upper GI endoscopy. METHODS: In a prospective study including 12 endoscopic centers, a total of 58 participants without any prior endoscopic experience were analyzed. During a practical training week in each center with the "Erlangen Endo-Trainer," an assessment using a "score card" protocol was used as reference method. Prior to the start of the training, various psy-tests (personality test, vigilance endurance test, test of spatial thinking and two tests of sensorimotor coordination) as well as assessment of the trainer were obtained. These parameters were compared with a blinded analysis of the performance at the end of the training. RESULTS: There was significant overall improvement during the training course. Multiple logistic regression analysis revealed that testing sensorimotoric coordination was significantly associated with defined improvement margins (odds ratio 11.46, p = 0.035). An expert's judgment on the prognosis correlated also significantly with the trainee's improvement (OR = 41.46; p = 0.018). Self-assessments were not significantly associated with performance or progress. CONCLUSIONS: Sensorimotoric tests may provide a reliable prediction of the trainee's learning progress. In contrast to self-assessment, the judgement of an experienced endoscopist provides the best guidance for the young candidate endoscopists prior to the start of his/her endoscopic training program.

Attention↗

Survival after surgical treatment of cancer of the rectum.

BACKGROUND AND AIMS: Rectal carcinoma is one of the most prevalent tumour types. Prognostic factors are of special interest to estimate prognosis of the individual patient. PATIENTS/METHODS: The data of 1,067 consecutive patients with solitary invasive rectal carcinoma, resected between 1988 and 1999 at the Department of Surgery of the University of Erlangen, were analysed. Cancer-related survival rate was calculated by univariate and multivariate analysis with respect to all relevant proven and probable prognostic factors. RESULTS: The R classification was found to be the parameter with the greatest influence on survival of patients with rectal carcinoma. Other tumour-related prognostic factors that influenced prognosis significantly were the anatomical extent, described by the TNM classification of the UICC, tumour grade and extramural venous invasion (EVI). In addition, the operating surgeon, a therapy-related factor, and the preoperative serum CEA level were found to influence prognosis. CONCLUSION: Tumour-related prognostic factors have the greatest influence on clinical decisions with regard to choice of a therapeutic concept. The increasing survival rates after treatment of rectal carcinoma have led to a focus on postoperative quality of life. Postoperative long-term global quality of life is similar to the preoperative level. Oncological outcome is still the most important factor, and tumour recurrence leads to a strong impairment of quality of life.

Adult↗

Expression of interleukin-6 and monocyte chemoattractant protein-1 by peritoneal sub-mesothelial cells during abdominal operations.

Cytokines and chemokines including interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) are secreted in response to major abdominal operations. The aim of this study was to identify the peritoneal cells that produce IL-6 and MCP-1. Samples of peritoneal tissue were taken from patients at the beginning and end of major abdominal operations. The samples were incubated in culture medium on microtitre plates for 5 h. The concentrations of IL-6 and MCP-1 were measured in culture supernatants by enzyme-linked immunosorbent assay (ELISA). In paraffin sections, cells that expressed IL-6 or MCP-1 were identified by combined in situ hybridization and immunohistochemistry. Antibodies against CD68, CD34, actin, and calretinin were included in these experiments. The median production of IL-6 increased significantly from 6256 pg/ml at the start of the operation to 20,000 pg/ml at the end. Production of MCP-1 rose from 7700 pg/ml to 11,820 pg/ml. IL-6 mRNA was mainly confined to endothelial cells. MCP-1 was expressed by a broader range of cells, consisting of actin-positive smooth muscle cells and endothelial cells, fibroblast-like cells, as well as occasional macrophages and mesothelial cells. Peritoneal endothelial cells contribute to the transient increase in concentrations of IL-6 in the circulation after surgical trauma. Recruitment of monocytes to the site of the trauma seems to be mainly effected by actin-positive smooth muscle cells and endothelial cells.

Adult↗

[Interdisciplinary aspects of surgery of the pelvis minor and retroperitoneum].

Surgery of diseases of the pelvis minor and retroperitoneum such as inflammatory disease, malignant tumours, or trauma of pelvic organs need the close interdisciplinary collaboration of visceral surgeons, gynaecologists, and urologists. This collaboration begins in planning diagnostic and therapeutic procedures. It has to be clear who performs which operative step and when. Excellent long-term results in malignant disease show that the greater effort is worthwhile. The rate of postoperative morbidity after these multivisceral resections is high also in specialised centers, but mortality is below 5%. Because of the growing number of long-term survivors, preservation of quality of life becomes more and more important.

Abdominal Injuries↗

[Sentinel lymph node in melanoma].

The procedure of sentinel node biopsy (SNB) has emerged as an important advance especially with respect to staging of malignant melanoma. Elective (prophylactic) lymph node dissection that had been practiced in primary melanoma with a suspected increased risk of (clinically occult) lymphatic metastasis has been replaced by SNB. Patients with proven metastatic involvement of the sentinel node (12-25%) can be specifically selected for regional lymph node dissection. Metastatic involvement of the sentinel node (SN) is a significant independent prognostic factor. The value of detecting metastasis by highly sensitive diagnostic tools such as RT-PCR is just as uncertain as is the therapeutic benefit of operative or conservative therapies in sentinel node-positive patients with respect to improving prognosis and is currently under study.

Clinical Trials as Topic↗

Innovations in fecal incontinence: sacral nerve stimulation.

OBJECTIVE: The aim of this study was to present an overview of sacral nerve stimulation in the treatment of fecal incontinence. We describe the evolution in technique, patient selection, and indications, and review results and complications. METHODS: All articles on sacral nerve stimulation for fecal incontinence that were recovered on MEDLINE search were reviewed. With multiple articles from an institution, the most recent reports with the longest follow-up and largest cohort of patients were selected, unless information from earlier reports was relevant. RESULTS: The technique of sacral stimulation is well established, carries little risk, and continues to be refined (e.g., a less invasive approach has been proposed). Patient selection is based on a two-stage diagnostic test stimulation (acute and subchronic), for which the predictive value is high. On this basis, permanent sacral nerve stimulation has proved effective in both single-center and multicenter trials in patients with a functional deficit but limited morphologic lesions or no morphologic lesions. The clinical benefit derives from multiple symptomatic improvements contributing to better bowel control and from substantially improved quality of life. The underlying mechanism of action remains undefined, but both somatic and autonomic function appears affected. CONCLUSION: Sacral nerve stimulation offers a safe treatment mode in a patient population in whom conservative treatment has failed and traditional surgical approaches would have limited success. The high predictive value of the diagnostic approach offers a unique therapeutic advantage.

Clinical Trials as Topic↗