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Biomedical subjects

B Böhm

Publications and source records attributed to B Böhm.

At least 73 records · Page 4Linked to original sources
PubMed1997

Does pneumoperitoneum with different gases, body positions, and intraperitoneal pressures influence renal and hepatic blood flow?

BACKGROUND: Because of the well-known negative effects of carbon dioxide pneumoperitoneum on the hemodynamic and respiratory system, it was questionable how pneumoperitoneum may affect hepatic and renal blood flow. Therefore the influences of different gases, different intraperitoneal pressures, and different body positions on hepatic and renal blood flow were investigated in a porcine model. METHODS: Cardiac and hemodynamic function were monitored by means of implanted catheters in the pulmonary artery and the femoral vein and artery. Renal and hepatic blood flow were recorded with a transonic volume flow meter placed at the renal and hepatic arteries and the portal vein. Eighteen animals were randomly assigned to receive one of three insufflation gases (carbon dioxide [CO2], argon, or helium. After baseline recording, one of three intraperitoneal pressures (8, 12, or 16 mm Hg) and one of three body positions (supine head up, or head down) were randomly chosen. After an adaptation time of 15 minutes, all data were recorded for 15 minutes. This was repeated until all nine combinations had been investigated. The end points of the study were blood flow in the hepatic and renal arteries and the portal vein, cardial output, systemic vascular resistance, and central venous pressure. RESULTS: Total liver blood flow was reduced on relation to intraabdominal pressure, head-up position, and argon insufflation. Arterial hepatic blood flow was reduced by the head-up position and argon insufflation. Portal venous blood flow decreased with the pig in the head-up position, with increased intraabdominal pressure, and argon insufflation. Renal blood flow was reduced by the head-up position and increased pressure. There was no correlation (p < 0.6) between systemic hemodynamic parameters (cardiac output, central venous pressure, and systemic vascular resistance) and hepatic and renal blood flow. CONCLUSIONS: Head-up position and intraperitoneal pressure greater than 12 mm Hg should be avoided during laparoscopic surgery because they compromise hepatic and renal blood flow. Argon insufflation impairs liver blood flow. However, helium may be advantageous compared with CO2 insufflation.

Animals↗
PubMed1997

[Progress in laparoscopic sigmoid resection in elective surgical therapy of sigmoid diverticulitis].

The full significance of laparoscopic technique in elective surgery of sigmoid diverticulitis has yet to be determined. However, it seems worthwhile to evaluate how minimally invasive surgery could be integrated into the surgical treatment of diverticulitis disease. Between January 1995 and August 1996, 26 patients with sigmoid diverticulitis underwent elective surgery. Following diagnostic laparoscopy, seven patients were treated with primary conventional resection, 15 patients with laparoscopic resection and four patients with laparoscopic-assisted surgery. One laparoscopic resection had to be converted to a median laparotomy. Postoperative complications (n = 2) only appeared in the group of conventional resections. Conventional resections required less time than laparoscopic or laparoscopic-assisted resections, but postoperatively, patients with laparoscopic resection were able to defecate sooner and required a shorter hospital stay. For 60% of the patients with diverticulitis disease of the colon, elective laparoscopic resection may prove to be the best alternative of surgical treatment. In selected patients it is a sound technique with a low complication rate. We recommend that all patients with diverticulitis disease requiring elective surgery undergo diagnostic laparoscopy to determine whether or not laparoscopic resection is a viable option.

Aged↗
PubMed1997

[Perspectives of minimal invasive surgery].

The rapid and often uncritical introduction of complex minimal invasive procedures in clinical routine has been increasingly criticized. Even established minimal invasive techniques as for instance laparoscopic cholecystectomy are discussed controversial. Causes hereof are the lack of basic research and the unstructured development of new operative techniques. The possibilities of physiology adjusted basic research in minimal invasive surgery and stepwise a structured testing of new operative techniques are demonstrated. The changing conditions of the next century demand critical evaluation of the effectiveness of video-endoscopic surgery in prospective randomized trials, if it will keep or expand its present clinical importance.

Forecasting↗
PubMed1996

[Effect of orthograde intestinal irrigation with Prepacol and polyethyleneglycol solution on duration of postoperative ileus after colorectal resections].

In a prospective randomized study in 100 patients undergoing conventional (n = 66) or laparoscopic (n = 34) colorectal resection, mechanical lavage with 2 l of a polyethylene glycol (PEG) solution (group A, n = 50) combined with a laxative was compared with lavage with 4 l of PEG alone (group B, n = 50). The influence of bowel preparation on postoperative ileus was investigated. The efficacy of bowel preparation was determined intraoperatively by a surgeon blind to the type of preparation. The time interval between the end of the operation an first flatus or bowel movement was recorded. The efficacy of preparation was no different between the groups (group A: 94%, group B: 84%; P = 0.5). The time lapse before first flatus (A: 3.1 +/- 1.2 days, B: 3.2 +/- 1.3 days; P = 0.6) or bowel movement (A: 3.9 +/- 1.3 days, B: 4.1 +/- 1.3 days; P = 0.5) also did not differ between the groups. The only factor found in multivariate analysis (age, sex, operation, duration and type of surgery, bowel preparation) to prolong the duration of postoperative ileus was the type of surgery. The first bowel movement occurred 3.2 +/- 1.1 days after conventional surgery and 4.3 +/- 1.2 days (P < 0.001) after laparoscopic surgery. The type of preoperative bowel preparation had no influence on the duration of postoperative ileus. The postoperative interval before the first bowel movement was shorter after laparoscopic surgery.

Aged↗
PubMed1996

Conserved amino acids in the N- and C-terminal domains of integral membrane transporter FhuB define sites important for intra- and intermolecular interactions.

Transport of iron(III) hydroxamates across the inner membrane of Escherichia coli is mediated by a peri-plasmic binding protein-dependent transport (PBT) mechanism. FhuB, the integral membrane component of the system, is composed of covalently linked halves (FhuB[N] and FhuB[C]) which still function when present as two distinct polypeptide chains. Our analysis of two uptake-deficient FhuB derivatives provides evidence for a mechanistically novel type of functional complementation: 'domain displacement' in the cyto-plasmic membrane. Amino acid residues 60 and 426 in the FhuB polypeptide chain may define key positions that are important for FhuB[N]-FhuB[C] interaction. Furthermore, FhuB derivatives, altered in either one of their conserved regions--typical of PBT related integral membrane proteins--displayed a dominant negative effect on ferric hydroxamate transport. The experimental data suggest that the two functionally equivalent conserved regions in FhuB[N] and FhuB[C] are primarily involved in the interaction with another component of the transport system, probably FhuC.

ATP-Binding Cassette Transporters↗
PubMed1996

[Work capacity, severe disability and needs for disability services in Thüringen with respect to demographic change].

Considerable changes are taking place in germany in respect of age groups (fewer youngsters, more old people), and this is bound to be reflected by the demography of the working population (15 to 64 years) during the next 50 years. It is shown in this contribution how the expected changes in age distribution in Thuringia will probably be reflected by the number of pensioners who are incapable of gainful employment or of exercising their original job for which they were trained. The proportion of younger persons who had to be pensioned because of inability to work or major disablement or severe need of nursing care, will decrease until 2040 A.D., these persons being in most cases about 10 years younger than the usual pensioning age. This entails a great need for medical, social and job rehabilitation in tremendous measure: a major challenge both in sociomedical and labour market policy respects.

Adolescent↗
PubMed1995

Postoperative intestinal motility following conventional and laparoscopic intestinal surgery.

OBJECTIVES: To evaluate the influence of conventional vs laparoscopic right-sided colectomy on postoperative motility of the stomach, small bowel, and large bowel, and to study the effects on postoperative intestinal motility of anesthesia only and of laparotomy vs laparoscopy only. DESIGN: Prospective randomized study in a canine model. SETTING: Animal research laboratory. ANIMALS: Twelve mongrel dogs weighting 23.4 to 29.6 kg. INTERVENTIONS: (1) Laparotomy or laparoscopy and (2) 1 week after complete recovery from the first procedure, right-sided colectomy with ileocolic anastomosis using conventional or laparoscopic techniques. End points of the study were (1) the postoperative time until the electrical response activity of the stomach, small intestine, and large intestine returned to a normal interdigestive pattern and (2) the time until first postoperative bowel movement occurred. RESULTS: Median time until return to normal interdigestive pattern of myoelectrical activity after laparoscopic colectomy was about 40% less than after conventional colectomy (P < .05). Time until first bowel movement was 27% reduced (P < .05). CONCLUSIONS: Recovery from postoperative ileus following laparoscopic surgery is more rapid than after conventional surgery in the canine model. Confirmatory human studies should be performed.

Animals↗
PubMed1995

Use of laparoscopic techniques in oncologic right colectomy in a canine model.

BACKGROUND: The purpose of this study was to evaluate the feasibility of laparoscopic oncologic righ colectomy (RC) with intraperitoneal ileocolic anastomosis (ICA) in a canine model. METHODS: In 21 dogs a laparoscopic RC with transection of the main right colic artery and removal of adjacent lymph nodes (LN) was carried out using an Nd:YAG contact laser and endoscopic stapler. Two weeks after surgery, all animals were killed. The number of remaining right colon mesenteric LN, length of remaining right colic artery, bursting pressure (BP) of ICA, and postoperative morbidity were evaluated. RESULTS: No major intraoperative complications were recorded. One dog died of pneumonia and heartworms. There were no postoperative septic or anastomotic complications. All dogs passed feces within the first 24 h postoperatively. Median operative time was 135 min (range 105-180 min). Length of remaining right colic artery after oncologic resection was 4.5 mm (range 3-7 mm), the number of remaining LN was 0, and the median anastomotic BP was 232 mm Hg (range 132-312 mm Hg). CONCLUSION: Oncologic resection of the right colon with high vascular ligation, wide mesenteric clearance of LN, and intraperitoneal anastomosis is feasible and safe in a canine model.

Anastomosis, Surgical↗
PubMed1995

Decay kinetics of N,N,N',N'-tetramethylbenzidine photocations in frozen micellar solution of cetyltrimethylammonium bromide.

After UV irradiation of rapidly frozen solutions of N,N,N',N'-tetramethylbenzidine (TMB) in dilute aqueous micellar cetyltrimethylammonium bromide at 80 K, the ESR signal corresponding to the TMB+ cation was detected indicating photoionization. This signal was monitored as a function of time at various temperatures between 80 K and 260 K. On a timescale of a few days the signal decayed to a plateau value that was stable for months. Two distinct second-order processes for the decay from the initial to the plateau value were observed: one prevailing at low temperatures with an activation energy of 0.6 kJ/mol, and one prevailing at T > 220 K with an activation energy of 13 kJ/mol. By means of spin probe investigations the latter process was shown to be connected with a local softening of the region adjacent to the micellar surface.

Benzidines↗
PubMed1994

Monopolar electrosurgery and Nd:YAG Contact Laser in laparoscopic intestinal surgery.

In a prospective randomized study using a canine model, we compared the use of monopolar electrosurgery (EC) (n = 23) and the Nd:YAG Contact Laser (CL) (n = 21) on intra- and postoperative morbidity in laparoscopic large-bowel resection. In EC, cutting was performed with scissors and coagulation was performed with electrosurgery. In CL, cutting and coagulation were carried out with the Nd:YAG Contact Laser. Laparoscopic oncologic right colectomy with intraperitoneal ileocolic stapled anastomosis was performed in all dogs. Intraoperative smoke development, difficulty of dissection, hemostasis, and postoperative adhesions were judged using a five-point score. Two weeks after surgery, all dogs were sacrificed and zoopsy was carried out. Three dogs died postoperatively from pneumonia and one from an anastomotic leak. There were no other postoperative complications. Operative time was 135 min (range 105-180) in the CL group and 145 min (range 60-210) in the EC group. Intraoperative smoke development, difficulty of dissection, and postoperative amount of adhesions were not different between groups (P > 0.05). Hemostasis in the CL group (median score of 1, range 1-2) was significantly better (P = 0.01) than in the EC group (median score of 2, range 1-5). Scissors and electrosurgery as well as Nd:YAG Contact Laser can be used successfully in intestinal laparoscopic surgery. Although the use of the Contact Laser did not cause less postoperative morbidity than the conventional method, there was significantly better hemostasis using the Nd: YAG Contact Laser.

Animals↗
PubMed1994

Animal models as educational tools in laparoscopic colorectal surgery.

Laparoscopic colectomies have been shown to be feasible in patients with low morbidity. Thus, many surgeons, as they begin to perform laparoscopic surgery on other areas of the abdomen, may consider performing laparoscopic colectomies. Although certain basic skills like suturing and knot tying can be practiced in training models, the preclinical performance of intraperitoneal bowel mobilization and anastomosis, dissection of mesentery, and control of bleeding can only be practiced and perfected in live animal models. We describe several laparoscopic intestinal techniques in porcine and canine models. Through use of these procedures, the surgeon can learn to handle intraperitoneal organs atraumatically, to achieve hemostasis, to dissect mesentery with lymphadenectomy and high ligation of major vessels, and to accomplish a variety of intraperitoneal anastomoses. Acquisition of these skills is essential in the quest to perform successful laparoscopic intestinal surgery. These skills cannot be learned in inanimate training models.

Anastomosis, Surgical↗
PubMed1994

Laparoscopic oncologic proctosigmoidectomy with low colorectal anastomosis in a cadaver model.

The purpose of this study was to demonstrate that a standardized approach to laparoscopic proctosigmoidectomy in a cadaver model with (1) initial proximal ligation of the inferior mesenteric (IM) vascular pedicle, (2) complete mobilization of the splenic flexure, and (3) intraperitoneal stapled colorectal anastomosis can be accomplished in complete accordance with oncologic surgical principles. Using nine cadavers in the fresh state, six abdominal wall cannulas were placed so as to allow good access to the left colon and rectum. After identifying the left ureter and gonadal vessel, the IM pedicle was divided close to the aorta and the left mesocolon was separated from the retroperitoneal structures. The sigmoid colon was transected at the proximal resection line with an endoscopic stapler; then the splenic flexure and descending colon were completely mobilized. The rectum was freed circumferentially, dissected first posteriorly, laterally, and anteriorly, and then transected in its middle portion with an endoscopic stapler. The specimen was removed through a widened left-lower-quadrant trocar incision and the anvil of a circular endoscopic stapler was placed into the proximal colon extraperitoneally. An intraperitoneal laparoscopic colorectal anastomosis was performed using a double-stapled technique. The median length of specimen was 53 cm (range 45-80 cm) and the median number of removed lymph nodes was 15 (range 11-20). A careful abdominal autopsy was carried out in all cadavers. Length of remaining inferior mesenteric artery was smaller than 1.5 cm in all cases and only one remaining lymph node (3 mm in diameter) was found adjacent to the IMA in one subject. No damage to either ureter occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Laparoscopic oncologic abdominoperineal resection.

PURPOSE: Although the use of laparoscopic techniques in colorectal surgery has recently become a focus of major interest in intestinal surgery, there is no proof that an oncologic abdominoperineal resection can be accomplished using laparoscopic techniques. The hypothesis of this study is that a standardized technique for laparoscopic oncologic abdominoperineal resection according to accepted oncologic surgical principles can be developed in a cadaver model. The end points of this study were intraoperative complications, success in performance of proximal vascular ligation of the inferior mesenteric artery, complete removal of the mesorectum including all lymph nodes adjacent to the named rectal arteries, and wide clearance of pelvic side walls. METHODS: Laparoscopic abdominoperineal resection was performed in 11 fresh cadavers (1 female and 10 males). After surgery, all cadavers underwent autopsy. The number of removed and remaining mesenteric lymph nodes, length of remaining inferior mesenteric artery, and mesorectal and the pelvic side wall soft tissue were evaluated. RESULTS: No major intraoperative complications were recorded. The median number of removed lymph nodes in the mesorectum was 12 (range, 6-22) and no remaining lymph nodes were found at the base of the inferior mesenteric artery. The median length of remaining inferior mesenteric artery was 5 (range, 1-15) mm. Wide lateral clearance of pelvic side walls was noted in all patients. CONCLUSION: A laparoscopic technique of abdominoperineal resection can be performed according to oncologic principles with proximal vascular ligation of inferior mesenteric artery, wide clearance of pelvic side walls, and complete removal of mesorectum using our described technique.

Abdomen↗
PubMed1994

Laparoscopic oncologic total abdominal colectomy with intraperitoneal stapled anastomosis in a canine model.

The purpose of this study was to evaluate the feasibility of performing an oncologic type of colectomy using laparoscopic techniques with intraperitoneal stapled ileorectal anastomosis in a canine model. In 21 dogs, laparoscopic oncologic colectomy was carried out using dissection with a contact Nd:YAG laser. The right, middle colic, and inferior mesenteric arteries were transected close to their origins, and all adjacent mesenteric lymph nodes were removed. Ileorectal anastomosis was performed using a circular end-to-end stapler especially designed for laparoscopic surgery. Two weeks after surgery, all animals were killed. The number of remaining mesenteric lymph nodes, bursting pressure of ileorectal anastomosis, and postoperative morbidity were evaluated. No major intraoperative complications were recorded. One dog died postoperatively from an anastomotic leak. All dogs passed feces in the first 24 postoperative hours. Median operative time was 145 min (90-240 min). The number of remaining colonic mesenteric lymph nodes was 0, and median anastomotic bursting pressure was 325 mm Hg (183-415 mm Hg). The median distance from ileocolic anastomosis to anal verge was 8.5 cm (6.0-11.0 cm). Laparoscopic oncologic colectomy with wide mesenteric clearance of lymph nodes and intraperitoneal stapled ileorectal anastomosis is feasible and safe in a canine model.

Anastomosis, Surgical↗
PubMed1994

[Laparoscopic ileocecal resection in Crohn disease].

Patients with Crohn's ileocolitis may undergo laparoscopic ileocolectomy if an abscess or fistula is not present. At the beginning of the procedure, the mesentery and right mesocolon is dissected from the retroperitoneum without mobilization of the lateral attachments. The ileocolic vessels are identified and clipped. The resection lines are marked, the mesentery is divided with scissors, and the vessels are clipped or coagulated. If the intestine is completely mobilized, a functional end-to-end-anastomosis can be carried out. Ten laparoscopic ileocolectomies were performed since May 1993: Patients' median age 31 years (range 22-39 years), 7 women and 3 men, median operative time 115 min. (range 45-220 min.). Two intraperitoneal anastomoses and three laparoscopic-assisted resections were accomplished. No intra- or postoperative complications were noted. The first postoperative bowel movement occurred in all patients by the fifth postoperative day. The median hospital stay was 5 days (range 4-7 days). An ileocolectomy can be performed as entire laparoscopic or laparoscopic-assisted procedure dependent on intraoperative findings. The morbidity is low and patients appear to recover quickly.

Adult↗
PubMed1993

[Histopathological changes of gallbladder and liver parenchyma in symptomatic cholelithiasis].

In a retrospective study of 1101 patients (302 men, 799 women; mean age 56,7 [19-88] years) with symptomatic cholelithiasis who had undergone elective cholecystectomy and intraoperative liver biopsy, histological examination revealed inflammatory changes in the gallbladder in 96.7%, chronic fibrotic cholecystitis in 94.5% and a severe form of cholecystitis in 8.8%. Clinically relevant changes in the liver parenchyma were present in 27.9%, most frequently intrahepatic cholangitis (21.8%). The latter was significantly more common in choledocholithiasis than in isolated cholecystolithiasis. 27 patients had signs of severe liver disease, namely viral hepatitis, cirrhosis or fatty liver. Since the gall-bladder in cholelithiasis is almost always inflamed, cholecystectomy is the treatment of choice. Not uncommonly liver biopsy will reveal clinically relevant changes in the liver parenchyma. This will be useful information, especially in the management of symptoms which persist postoperatively.

Adult↗