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Biomedical subjects

W Hohenberger

Publications and source records attributed to W Hohenberger.

At least 37 records · Page 2Linked to original sources
PubMed2004

Functional outcome after intersphincteric resection of the rectum with coloanal anastomosis in low rectal cancer.

OBJECTIVES: Anterior rectal resection with partial removal of the internal sphincter is an option for low rectal cancer. The objective of this study was to evaluate the functional outcome after this intersphincteric rectal resection. METHODS: Anal continence was evaluated by anorectal manometry and a standardized questionnaire (Wexner Score) in 33 patients 28+/-15 weeks and 100+/-45 weeks, respectively, after intersphincteric resection. Nineteen of the 33 patients were reconstructed with a straight anastomosis; 12 received a colonic J-pouch. RESULTS: Post-operatively, 25.8% of the patients were incontinent to solid stool and 54.8% were incontinent to liquid stool at least once a week. Mean and maximum resting tone (24+/-10 and 40+/-13 mmHg), maximum tolerable volume (77+/-28 ml) and rectal compliance (1.4+/-1.2 ml/mmHg) were reduced in anorectal manometry. Squeeze pressures remained unchanged. Only the maximum tolerable volume correlated significantly with the continence score (r=-0.45, p<0.05). The Wexner score and maximum tolerable volume were significantly better after colonic J-pouch reconstruction than after straight anastomosis (9.9+/-4.5 vs 13.4+/-4.0, p<0.05, 65+/-20 ml vs 100+/-27 ml, p<0.01). CONCLUSION: Intersphincteric resection of the rectum leads to impaired post-operative continence. The functional outcome is improved with a colonic J-pouch.

Adult↗
PubMed2004

Determination of nodal status and treatment in early gastric cancer.

BACKGROUND: In view of its low associated risk of metastatic spread, early gastric cancer has an excellent prognosis. The basis for the choice of treatment is the risk of lymphogenous metastatic spread together with the individual surgical risk. METHODS: The data collected from 279 patients in whom, between 01/1982 and 12/2001, a gastric resection or gastrectomy was carried out for early gastric cancer at the Surgical Department of the University Hospital, Erlangen, were analysed. A number of macroscopic and histopathological factors were examined by univariate and multivariate analysis for their effect on lymphogenous metastatic spread. RESULTS: In 33 patients (11.8%), regional lymph-node metastases were confirmed histologically. The grade of malignancy (high-grade, relative risk 9.9), diameter (>20 mm, relative risk 5.0) and lymphatic invasion (relative risk 3.5) all demonstrated a significant independent influence on the occurrence of regional lymph-node metastases. Seventy-three patients were identified as a low-risk group, with a risk of lymphogenous metastatic spread of only 1%. CONCLUSIONS: Well differentiated or moderately differentiated carcinomas having a diameter of less than 2 cm can be treated by local intervention, such as local excision or endoscopic removal, without any increase in risk, provided that the tumour is reliably removed without residual tumour (histologically confirmed R0). In the presence of an elevated surgical risk, the choice of treatment must be made on an individual basis.

Adult↗
PubMed2004

[Salvage of exposed alloplastic materials in irradiated wounds - a case report].

BACKGROUND: Modern multimodal concepts of complex reconstructions and advanced wound management enlarge strategies for surgical oncological therapies. One of the mainstays of classical surgical therapy in case of exposed alloplastic materials in irradiated wounds was to remove the foreign body due to the risk of infection. This loss of integrity and function of the contaminated host bed was to allow wound healing and closure. METHOD: We report the management of a 56-year-old female patient who developed a lyomyosarcoma at her left shoulder girdle 8 years after radiation of the left thorax because of breast cancer. After radical tumor resection and exarticulation of her left arm in the shoulder joint a necrosis of the soft tissue envelope developed, leading to an exposed alloplastic mesh. Staged debridement and continuous application of negative pressure was performed three times. Ultimate plastic coverage was performed by means of a pectoralis myocutaneous island flap from the other breast. RESULTS: After staged debridement and repeated vacuum application excellent wound cleaning, neovascularisation, wound contraction and formation of granulation tissue within the previously irradiated tissue zone was observed. Until fourteen months postoperative wound coverage remained stable and no signs of infection were observed. DISCUSSION: By means of negative pressure therapy even in radiated wounds excellent wound cleaning and sufficient formation of granulation tissue can be achieved. In some cases negative pressure therapy together with staged debridement allows reintegration of exposed and therefore potentially contaminated alloplastic meshes into new formed granulation tissue in radiated wounds respectively radiation ulcers. Thus leading to the possibility of ultimate plastic coverage.

Breast Neoplasms↗
PubMed2004

Simplification of rat intubation on inclined metal plate.

Small-animal intubation is often necessary during inhalation anesthesia to allow steady-state conditions for large operations and in vivo experiments in all fields of experimental surgery. In rats, placing an orotracheal tube is technically difficult primarily because of the small size of the subject and the lack of equipment specifically designed for this task. We describe a simple rat intubation technique in which the animal is suspended in dorsal recumbency on an inclined metal plate. The animal, anesthetized with ether, is fixed to a 70 degrees-inclined metal plate in a dorsal position by means of a Mersilene ribbon hooked around the upper incisors. This method of positioning the animal is the most important step in the intubation process and further facilitates the technique already described by other authors. A human otoscope was used as a laryngoscope, intubation was performed using the Seldinger technique, and a 14-gauge intravenous catheter served as an endotracheal tube. This inexpensive technique is quickly learned and can be used in any laboratory. Safe and reliable airway management can thus be achieved, permitting in vivo examinations and operations.

Anesthetics, Inhalation↗
PubMed2004

Evaluation of computer-assisted image enhancement in minimal invasive endoscopic surgery.

OBJECTIVES: This paper focuses on the evaluation of the usage of computer-aided image processing methods for minimal invasive surgery. During video endoscopy of visceral cavities the images are displayed directly on the monitor without further processing. In the course of the operation the former good quality of the images decreases due to typical disturbances like bleeding, smoke or flying particles. These disturbances can be reduced by using image processing methods like color normalization, temporal filtering or equalization. METHODS: In this double-blinded analysis, 14 surgeons with different levels of experience evaluated 120 image pairs and 5 image sequences, directly comparing original and processed images or movies. RESULTS: Color normalization and equalization proved to significantly enhance video endoscopic images. With regard to temporal filtering, an improvement could be seen in the image sequences with filter size 5 being a greater enhancement than filter size 3. Comparing the state of experience and its influence on the results, it occurred that the experienced surgeons preferred the original color while altogether agreeing that the color-normalized images were better. CONCLUSIONS: The results obtained in the present evaluation show that the image processing methods which were used can significantly improve the quality of video endoscopic images. As a result of this, necessary lavages of the operated area are reduced and a better overview and orientation for the surgeon can be reached.

Humans↗
PubMed2004

Light fields for minimal invasive surgery using an endoscope positioning robot.

OBJECTIVES: To generate a fast and robust 3-D visualization of the operation site during minimal invasive surgery. METHODS: Light fields are used to model and visualize the 3-D operation site during minimal invasive surgery. An endoscope positioning robot provides the position and orientation of the endoscope. The a priori un-known transformation from the endoscope plug to the endoscope tip (hand-eye transformation) can either be determined by a three-step algorithm, which includes measuring the endoscope length by hand or by using an automatic hand-eye calibration algorithm. Both methods are described in this paper and their respective computation times and accuracies are compared. RESULTS: Light fields were generated during real operations and in the laboratory. The comparison of the two methods to determine the unknown hand-eye transformation was done in the laboratory. The results which are being presented in this paper are: rendered images from the generated light fields, the calculated extrinsic camera parameters and their accuracies with respect to the applied hand-eye calibration method, and computation times. CONCLUSION: Using an endoscope positioning robot and knowing the hand-eye transformation, the fast and robust generation of light fields for minimal invasive surgery is possible.

Algorithms↗
PubMed2003

Peritoneal carcinomatosis of colorectal cancer: incidence, prognosis, and treatment modalities.

BACKGROUND AND AIMS: Intraperitoneal carcinomatosis accounts for 25-35% of recurrences of colorectal cancer. Studies demonstrate that peritoneal carcinomatosis is not necessarily a terminal condition with no options for treatment or cure. RESULTS: The combination of aggressive cytoreductive surgery and intra-abdominal hyperthermia chemotherapy improves long-term overall survival in selected patients but is a time-consuming procedure (approx. 12 h) and entails high mortality (5%) and morbidity (35%)). Most commonly used drugs are mitomycin C and platinum compounds, which have synergistic toxic effects on tumor cells when hyperthermia is applied. CONCLUSION: Since combined treatment seems promising only in peritoneal carcinomatosis stages I and II, the precondition for a reasonable combined treatment is careful staging. The mode of chemotherapy, the kind of drugs used for chemoperfusion, the timing of surgery, and the role of additional systemic chemotherapy must be evaluated in randomized studies.

Carcinoma↗
PubMed2003

Incisional hernia repair after orthotopic liver transplantation: a technique employing an inlay/onlay polypropylene mesh.

BACKGROUND: The literature provides no data on the incidence and operative management of incisional hernias developing after orthotopic liver transplantation. The use of high-dose immunosuppressive agents results in an appreciable delay in wound healing. There is thus a need for a procedure for the reconstruction of the abdominal wall for patients on immunosuppression. The aim of this retrospective study was to establish the incidence of incisional hernias and an analysis of the results after implantation of a polypropylene mesh in inlay-onlay technique after liver transplantation is given. METHODS: The basis for the present retrospective investigations was a total of 207 liver transplantations carried out in 192 patients (15 re-transplantations). After performing tensiometry, a polypropylene mesh (Marlex) was implanted to close the hernias using the inlay/onlay technique or a direct closure of the fascia was done. All treated hernias were followed up for a median of 18 months. RESULTS: Among 184 patients, 17 developed incisional hernias after primary direct closure of the abdominal wall, giving an incidence of 9%. In an additional 8 patients an incisional hernia was seen where an absorbable mesh was used to close the abdominal wall after liver transplantation. In addition, there were 25 incisional hernias after 207 liver transplantations (12%). One of 15 (7%) of the surgically repaired hernias with implantation of a polypropylene mesh (Marlex) developed a recurrence. All the 3 patients after direct apposition of the fascia without using a polypropylene mesh suffered a recurrence (3 of 3; 100%). Significant risk factors for developing an incisional hernia were the amount of ascites and the stay in the ICU after transplantation. Neither severe deep nor superficial wound infection nor bowel fistulas were observed after implantation of a inlay/onlay mesh. CONCLUSION: In patients after liver transplantation, the implantation of a polypropylene mesh proved to be an efficient and safe method of treating incisional hernias. Implantation of a mesh was not associated with an increased infection rate, despite the use of immunosuppression. In view of the high recurrence rate associated with primary closure, mesh implantation should be given preference.

Female↗
PubMed2003

Differential effects of surgical sympathetic block on sudomotor and vasoconstrictor function.

OBJECTIVE: To assess the effects of a surgical block of the sympathetic chain at the T2 level on vasoconstriction and palmar sweating in patients with palmar hyperhidrosis. METHODS: In a prospective study, sympathetic vasoconstriction was measured by laser-Doppler imaging and by computer-assisted infrared thermography (rewarming kinetics following immersion of both hands in ice water [4 degrees C, 30 seconds]) in 61 patients with hyperhidrosis preoperatively and 2 days and 3 months postoperatively. In addition, palmar sweating preoperatively and 3 months postoperatively was assessed by quantitative sudometry. RESULTS: Before surgery, rewarming kinetics was significantly slower in the patients (n = 61) than in the healthy control subjects (n = 28). Two days after the block, baseline skin temperature increased by about 5 degrees C, and rewarming was massively accelerated in each of the patients. Three months postoperatively, rewarming kinetics was still accelerated in 36 hands, was unchanged from the preoperative condition in 42, and had worsened in 12. These changes were accompanied by parallel alterations of laser-Doppler flux. However, palmar sweating was massively reduced in all but one patient, irrespective of the different rewarming kinetics. CONCLUSIONS: T2 sympathectomy leads to long-lasting inhibition of palmar sweating, which does not correlate to loss of vasoconstriction. Recurrent and enhanced vasoconstrictor function 3 months following endoscopic sympathetic block has major implications for its use to treat enhanced vasoconstriction.

Adolescent↗
PubMed2003

The pathological assessment of mesorectal excision: implications for further treatment and quality management.

BACKGROUND AND AIMS: Most clinical practice guidelines today recommend total mesorectal excision (TME) for carcinoma of the middle and lower rectal thirds and partial mesorectal excision (PME) for the upper rectal third. However, these procedures may not always fulfill the oncological requirements. The pathological examination of resected rectal carcinomas should always include a visual assessment of the mesorectal excision to ensure oncological adequacy and appropriate quality. The clinical practice guideline of the German Cancer Society recommends reporting of the distal extent of mesorectal excision (total or partial without coning) and the excision in an inviolate fascial envelope. PATIENTS AND METHODS: Reporting schemas of assessment and documentation for daily use and for studies are presented. RESULTS: Careful macroscopic evaluation of the resection specimen should be standardized. This may be supplemented by stain marking after postoperative filling the inferior mesenteric or superior rectal artery with ink or methylene blue solution. Photodocumentation is highly desirable. The pathological assessment of adequacy of mesorectal excision should be taken into account in selection for adjuvant radiotherapy. Objective macro- and microscopic assessment of mesorectal excision by pathologists is essential for quality management throughout patient care and in clinical trials.

Carcinoma↗
PubMed2003

Angiogenesis and dendritic cell density are not correlated with metachronous distant metastasis in curatively operated rectal cancer.

BACKGROUND AND AIMS: Apart from surgery, treatment of rectal cancer increasingly involves the use of (neo-)adjuvant strategies. To optimize the selection process for these therapy regimens, especially in the field of cellular and molecular biology, new prognostic factors additional to the established TNM system are being investigated. PATIENTS AND METHODS: Two groups of patients ( n=2x85) with rectal carcinoma curatively treated by surgery alone were studied retrospectively (median follow-up 6.1 years). To exclude the effect of the surgeon only patients free of locally recurrent disease were selected. Patient groups were matched for age, gender, UICC stage, and year of operation (1982-1991) and differed only in subsequent metachronous distant metastatic spread, i.e., the criterion to be studied. The factors investigated in uni- and multivariate analysis were angiogenesis, density of dendritic cells, grading, venous invasion, and lymphatic invasion. RESULTS: Grading invariably proved to be the only significant prognostic factor. In univariate analysis the absence of venous invasion was also correlated significantly with increased disease-free survival. CONCLUSION: Angiogenesis and dendritic cell density are not prognostic factors for metachronous distant metastasis in rectal cancer and therefore cannot serve as selection parameters for adjuvant therapy.

Age Factors↗
PubMed2003

[Laparoscopic cholecystectomy. Training on a bio-simulation model with learning success documented using score-cards].

The possibilities of gaining theoretical knowledge in surgery are virtually unlimited. To acquire practical skills,however, the availability and willingness of the patient are the limiting factors. With the development of training tools and structured courses, experience can be gained independently of the clinical situation. To objectify and record individual performance and improvement, and to define further potential, a scoring system is necessary. Using the example of laparoscopic cholecystectomy, a training program was combined with an evaluation system and the beginners' learning curves were recorded during the course of a training week. The present study shows that first experiences and measurable improvements can be reliably assessed within one week's structured training on a simulation model.

Animals↗
PubMed2003

[Prognostic relevance of biological and molecular markers in oncology. Criteria for planning and interpreting studies].

Experts on different specialties (surgery, pathology, molecular biology and medical statistics) discussed the evaluation of prognostic factors during a workshop. The most important results presented are: (1) the prognostic relevance of new biological or molecular markers must be evaluated in a phase-III prognostic study. To establish such a marker in the UICC-TNM-classification in at least two different centers, two multivariate analyses according to defined criteria are necessary; (2) the standards of laboratory methods have to be defined, e.g.,which method to apply for RNA-analysis,which materials to used, etc; (3) intensive data analysis should be done before using methods of multivariate analysis. The criteria for the presentation of survival curves are given in detail; (4) in multivariate analysis, the Cox proportional hazard regression for survival outcomes is discussed with explanations and examples of the terms relative risk, odds-ratio, hazard and relative hazard. The arrangement and interpretation of a good prognostic study should be performed as an interdisciplinary approach.

Biomarkers, Tumor↗
PubMed2003

[Sacral nerve stimulation in the treatment of faecal incontinence].

BACKGROUND: Sacral nerve stimulation is a recent development in the treatment of faecal incontinence. This paper reports the experiences of a single center on the use of this technique since its first application. PATIENTS AND METHOD: Based on the functional results of a temporary test stimulation phase, 16 patients underwent operative implantation of a permanent neurostimulation device. Due to a functional deficit of the morphologically intact anal sphincter, all patients suffered from incontinence for liquid and solid stool. The aetiology varied among the patients. The median duration of symptoms was 8.5 years (2-30). Clinical function was evaluated by standardized questionnaires, the Cleveland Clinic incontinence score and the disease specific quality of life instrument (FIQL-ASCRS) before and during stimulation. Anorectal physiology was tested by anorectal manometry. RESULTS: Functional improvement was achieved in 94% of the patients. At a median follow-up of 32.5 months (3-99) treatment was successful in 81%. The percentage of incontinent bowel movements decreased from a median of 40% (5-100) before stimulation to 0% (0-20) with stimulation ( P=0.001). The Cleveland Clinic incontinence score improved from a median of 17 (11-20) to 5 (0-15) ( P=0.003). The quality of life index was improved in all categories.Mean squeeze pressure was increased form a median of 44 to 75 mmHg with stimulation ( P=0.003) and maximal squeeze pressure from a median of 69 to 97 mmHg (P=0.009). Resting pressure, perception, urge threshold and maximum tolerable volume were not significantly changed. CONCLUSION: Sacral nerve stimulation is an effective treatment for faecal incontinence. Morbidity is low. Sacral nerve stimulation is indicated, if conservative treatment fails and more conventional surgical approaches are of limited success.

Adult↗
PubMed2003

[Local therapy principles in rectal carcinoma].

In the therapeutic algorithm for treatment of rectal cancer, primarily in the lower two-thirds of the rectum, local excision currently plays a limited role, but clearly adheres to diagnostic, oncologic, and technical principles. This should be considered particularly against the background that aspects of maintaining function and the associated positive effects on quality of life, based on expanding knowledge of the complications of radical interventions and their ramifications, have gained in importance. The following addresses the oncologic-histologic, clinical-diagnostic, and technical principles of local excision as well as the results for patients treated according to the devised diagnostic/therapeutic algorithm and included in the Erlanger Register of Colorectal Cancer (ERCRC).

Adult↗
PubMed2003

Does conversion of immunosuppressive monotherapy from cyclosporine A to tacrolimus improve bone mineral density in long-term stable liver transplant recipients?

The effects of converting cyclosporine A to tacrolimus on bone mineral density (BMD) have not yet been evaluated thoroughly in liver transplant patients. Interfering factors in this patient population often are concomitant glucocorticoid treatment or exposure to estrogens. Here, we investigated in a homogeneous population of 10 male liver transplant recipients the impact of converting low-dose cyclosporine A monotherapy to low-dose tacrolimus monotherapy on BMD by using dual-energy x-ray absorptiometry. During the 12-month study period, an increase in BMD at the lumbar spine was observed in 9 out of 10 men (P <.01), whereas BMD at the femoral neck remained stable. Converting cyclosporine A to tacrolimus appears to be safe and efficaceous with regard to maintaining or even increasing BMD in male liver transplant recipients.

Alkaline Phosphatase↗
PubMed2003

Mannan-binding lectin (MBL) serum levels and post-operative infections.

Mannan-binding lectin (MBL) is a central component of the innate immune system. Here we investigated the role of MBL in surgical patients during the peri-operative phase. Basal and post-operative (days 1-3 post-surgery) serum samples were obtained prospectively from 156 patients undergoing major elective gastrointestinal surgery for malignant disease. In contrast to procalcitonin (a typical acute-phase protein), there was no significant difference in serum MBL between pre- and post-operative samples (P=0.62). Nevertheless, patients who developed post-operative infections showed significantly lower pre- and post-operative MBL levels than those who did not (P=0.013 and P=0.005, respectively). There was no significant difference in pre-operative procalcitonin between the two groups (P=0.56). We conclude (i) that serum MBL levels did not respond immediately to surgical trauma, and (ii) that lower MBL levels were associated with an increased occurrence of post-operative infections. Studies on larger patient groups are necessary, however, to assess the value of MBL measurements in identifying patients at risk of post-operative complications.

Adult↗