Adhesions after intraabdominal surgical procedures are related to high morbidity and mortality. Biomaterials, particularly those made of polypropylene, in the intraabdominal position have to be considered as pathophysiological cofactor in a multifactorial process of adhesion formation. To investigate the adhesive potential induced by the biomaterial, an animal model was performed. In addition, the influence of coverage by omentum or a polyglactin barrier was investigated.

Organizer and Guest Editor H.-G. Rau, Dachau, Germany in honor of Prof. Dr. Dr. h.c. F.W. Schildberg, Munich, Germany Basel · Freiburg · Paris · London · New York · Bangalore · Bangkok · Singapore · Tokyo · Sydney Eur Surg Res 2003;35:123–141 DOI:10.159/000070276

Background and Aims: The study was designed to asses the adhesiogenic capacity of silicone drainages and the protective effect of phospholipids (PL). Materials and Methods: A total of 75 Wistar rats were randomly assigned to the different groups. In a preliminary trial (pt; n = 15), all rats underwent midline laparotomy. The control group (Cpt; n = 5) received no further treatment. In the other animals, either an ‘easy flow’ drainage (EFpt; n = 5) or an ‘Aachen’ drainage (ACpt; n = 5) was placed into the abdominal cavity. In the final study (fs; n = 60), rats underwent laparotomy and colonic anastomosis. The control groups (Cfs) received no drainages. In the other groups either one of the two types of drainages (EFfs, ACfs) were introduced. In 50% of the rats, 75 mg/kg of PL were administered intraperitoneally (Cfs+PL, EFfs+PL, ACfs+PL). The other rats received no additional treatment (CfsØPL, EFfsØPL, ACfsØPL). All animals were sacrificed 10 days after surgery. Areas of adhesions and anastomotic bursting pressures were measured (mean ± SD). Results: In the preliminary trial, analysis of variance (ANOVA) revealed no differences between the groups after application of drainages (values are given in mean ± SD): Cpt mean 23.3 ± 29.4 mm2, EFpt 829.7 ± 679.3 mm2, ACpt 609.9 ± 219.4 mm2. In the final study, 2-factorial ANOVA showed a significant effect (p < 0.001) for the use of drainages but not for the application of PL (CfsØPL 140.6 ± 124.2 mm2, Cfs+PL 67.7 ± 60.4 mm2, EFfsØPL 1,217.0 ± 458.3 mm2, EFfs+PL 1,266.8 ± 368.3 mm2, ACfsØPL 861.7 ± 274.8 mm2, ACfs+PL 544.2 ± 193.8 mm2). Post hoc test for pairwise comparisons adjusted to Bonferroni showed significant differences (p < 0.001) between all of the three pairs (Cfs 104.1 ± 92.3 mm2 vs. EFfs 1,241.9 mm2 ± 413.3 mm2; Cfs vs. ACfs 702.9 mm ± 234.3 mm2; EFfs vs. ACfs). Discussion: The final study demonstrates the adhesiogenic capacity of silicone drainage tubes in combination with anastomoses. Any protective effect of PL alone or in combination with drainages could not be shown. Conclusions: Indication for the use of drainages in standard surgical procedures should be reconsidered within the scope of their potential to cause adhesions and subsequent complications.

Epidural application of bupivacaine hasbeen suggested to have a sympatholytic effect on spinal reflexmechanisms that shortens postoperative paralysis and leads to animproved transit time. The influence on anastomitic healing remainscontroversial. Laparotomy was performed in eight dogs. A short segmentof the distal colon was resected and five electrodes were fixed on theserosa to measure the myoelectric activity (e.g., Migrating MyoelectricComplex—MMC). After operation a peridural catheter was placed betweenL7 and the sacral crest. One milliliter of bupivacaine 0.25% for each3 kg of body weight was injected every 4 hours. Barium pellets coatedin wax were placed into the stomach to allow radiographicrepresentation of transit time. After 5 days the colon anastomosis wasresected to measure the bursting pressure. In the peridural analgesiagroup (PDA) we found one small bowel intussusception and one coveredanastomotic leakage. Postoperative PDA led to early and severemyoelectric activity but did not influence the time until the first MMCoccurred (44 ± 0.8 h, PDA; 44.6 ± 1.5 h,control). Neither the transit time to the colon (50.2 ± 1.9h, PDA; 51.7 ± 5.5 h, control) nor the anastomotic healingwas influenced (bursting pressure: 176 ± 21.1 mmHg, PDA; 152± 27.7 mmHg, control). Postoperative epidural analgesia withbupivacaine shortens intestinal paralysis. Early myoelectric activitywith a lack of propulsive activity can cause complications like smallbowel intussusception. Hence early postoperative enteral nutritionafter epidural analgesia is risky. Because the influence of epiduralanalgesia on propulsive motility remains unclear, it seems reasonableto recommend its limited use in colon surgery.

BACKGROUND:Postoperative peritoneal adhesions are a major complication of abdominal surgery. Adjuvant therapy is needed to prevent adhesion formation and subsequent sequelae. Previously published data proved the efficacy of phospholipids (PL) for this indication; however, additional information on drug safety was still outstanding. The underlying study was designed to investigate the influence of phospholipids on three different types of healing tissue.MATERIALS AND METHODS:A total of 48 Chinchilla rabbits underwent median laparotomy, standardized abrasion of the visceral and parietal peritoneum, jejunal anastomosis, and an electrocautery incision of the liver. The operation was completed by intraperitoneal administration of 10 ml/kg of either normal saline (NaCl) or phospholipids (12%).RESULTS:After 5 (NaCl 691 mm(2) vs PL 192 mm(2)) and 10 days (NaCl 625 mm(2) vs PL 88 mm(2)) the control group presented with significantly larger adhesion areas (P < 0.05). The bursting pressure of the anastomosis on the 5th (NaCl 16.1 kPa vs PL 18.2 kPa) and 10th (NaCl 19.7 kPa vs PL 18.6 kPa) postoperative days showed no statistically significant difference. The tensile strength of the laparotomy wound measured after intervals of 5 (NaCl 8.5 N cm(-1) vs PL 6.8 N cm(-1)) and 10 days (NaCl 23.0 N cm(-1) vs PL 20.2 N cm(-1)) was not statistically different either. The collagen protein ratio of anastomoses, laparotomy wounds, and liver incisions as well as the inflammatory-reparative response of the different tissues was not affected by PL.CONCLUSIONS:These results confirm the efficacy of phospholipids in adhesion prevention. The findings of uncompromised healing of anastomoses, laparotomy wounds, and liver incisions demonstrate the safety of this agent. Further data may qualify phospholipids for a clinical trial.

BACKGROUND:Isoperistaltic colon is preferred to antiperistaltic colon for esophageal replacement, but experimental data do not exist to support this practice. METHODS:In 7 dogs a 20 cm long colon loop was interposed between the skin and the small bowel, isoperistaltically in 3 dogs and antiperistaltically in 4 dogs. Three months later five strain-gauges were implanted and evacuation was investigated by motility testing, barium studies, and scintigraphy. RESULTS:Motility recording showed normal colon motility in the excluded loops. Quiescent states (duration 40.2 +/- 13.6 minutes) were followed by contractile states (duration 7.5 +/- 2.4 minutes, frequency 3.3 +/- 0.6 per minute). The main peristaltic direction of isoperistaltic loops was isoperistaltic, and the main peristaltic direction of antiperistaltic loops was antiperistaltic. Evacuation took place exclusively during the contractile status. Half time emptying was more rapid in isoperistaltic loops (35 +/- 11 vs 69 +/- 16 minutes). The content of antiperistaltic loops was held back by antiperistaltic activity. Application of oatmeal porridge into the loops shortened the quiescent status from 40.2 to 13.2 +/- 4.8 minutes. CONCLUSIONS:The colon graft for esophageal replacement is an active system. Food is stored during the quiescent states and evacuated during the contractile states. The original peristaltic direction is preserved so that retroperistalsis in antiperistaltic loops may lead to patient discomfort and pulmonary complications.

Background: Adjuvant therapy is needed to prevent adhesion formation as a major cause of postoperative morbidity and mortality. Previously published data proved the efficacy of phospholipids (PL) for this indication; however, additional information on drug safety was still outstanding. This study was designed to investigate the influence of phospholipids on three different types of healing tissue. Materials and Methods: A total of 48 Chinchilla rabbits underwent median laparotomy, standardized abrasion of the visceral and parietal peritoneum, jejunal anastomosis, and an electrocautery incision of the liver. The operation was completed by intraperitoneal administration of 10 ml/kg of either normal saline (NaCl, 0.9%) or phospholipids (PL, 12%). After intervals of 5 and 10 days, respectively, 50% of the surviving animals were sacrificed and adhesions were measured using a digitizer board. The fresh 10-cm long segment of the jejunum carrying the anastomosis was examined using a bursting experiment. Tensile strength of the midline laparotomy wound was assessed. Specimens of the scar tissue of liver, anastomosis, and abdominal wall were stained with Sirius red and Fast green to determine the collagen protein ratio. Results: After 5 (NaCl 691 mm2 vs. PL 192 mm2 ) and after 10 days (NaCl 625 mm2 vs. PL 88 mm2) the control group presented with significantly larger adhesion areas (p < 0.05). The bursting pressure of the anastomosis on the fifth (NaCl 16.1 kPa vs. PL 18.2 kPa) and tenth (NaCl 19.7 kPa vs. PL 18.6 kPa) postoperative day showed no statistically significant difference. The tensile strength of the laparotomy wound measured after intervals of 5 (NaCl 8.5 N cm-1 vs. PL 6.8 N cm-1) and 10 days (NaCl 23.0 N cm-1 vs. PL 20.2 N cm-1) was not statistically different either. The collagen protein ratio of anastomoses, laparotomy wounds, and liver incisions, as well as the inflammatory reparative response of the different tissues, were not affected by PL. Conclusions: These results prove the efficacy of phospholipids in adhesion prevention. The findings of uncompromised healing of anastomoses, laparotomy wounds, and liver incisions reveal the safety of this agent. Further data may qualify phospholipids for a clinical trial.

Two-third-resections of the proximal or distal small bowel with and without artificial valves were performed in rats. Intestinal adaptation led to a significant increase in bowel diameter, villus height and villus diameter and consequently in absorptive mucosal surface area per unit of serosal area. Additional artificial valve construction did not affect the calculated mucosal surface area after proximal resection, while it significantly decreased the absorptive area by the occurrence of large, plump villi after distal resection. There was no change in small-intestinal absorption of water, glucose and electrolytes per unit mucosa with valve construction. DNA cytometry showed that artificial valves led to mucosal hyperplasia without hypertrophy. These morphological changes coincided with a significant increase in basal and stimulated gastrin release. The body weight was unchanged or even worse in the valve groups than after resection alone, despite a significantly prolonged transit time. Therefore, in our study, artificial valves did not result in functional improvements after small intestinal resections.

In an animal experimental study we examined the postoperative recovery of the motility of the upper gastrointestinal tract after operative treatment of a benign gastric outlet obstruction. At 45 Days after induction, a duodenal stenosis was resected in six dogs, and resolved by Finney's duodenoplasty in another six dogs. Fourteen days after segmental resection, the gastric emptying was faster [half evacuation time (T1/2) for semisolid food = 44.4 ± 16.8 min] than following duodenoplasty [T1/2 = 56.8 ± 25.3). Here motor migrating complexes (MMCs) started in the antrum and could be traced down to the jejunum. After segmental resection we recognized MMC only distal to the anastomosis. The duration of the whole MMC cycle (69.0 ± 18.6 min) as well as of the single phases was significantly shorter in the resection group than after duodenoplasty (108.0 ± 15.1 min). At 28 days after operation the differences in the electromyographic findings were smaller (82.0 ± 15.1 min vs. 111.4 ± 11.2 min), but still significant. Obviously humoral transmitters and the extrinsic neural system lead to good propagation of the MMC across the anastomosis, even before the intramural pathways are reestablished. Concerning the fast recovery of the motility of the upper gastrointestinal tract, duodenoplasty is superior to segmental duodenal resection.

Die Pouchbildung ist in der Abdominalchirurgie ein etabliertes Verfahren, das darauf abziehlt, eine durch Resektion verlorengegangene Reservoirfunktion wiederherzustellen. So kann die Intestinalpassage nach totaler Gastrektomie durch einen Jejunum-Pouch rekonstruiert werden [3, 6, 11]. Die Bildung eines Ileum-Pouches nach Proktokolektomie ist ein anerkanntes und definitives Verfahren zur Behandlung der Colitis ulcerosa und der familiären Polyposis coli [1, 2, 5]. In beiden Fällen wird der Dünn-darm-Pouch in den meisten Fällen als J-förmige Duplikatur des Dünndarms angelegt. Der Pouch besitzt somit einen iso- und anisoperistaltischen Schenkel, wobei beim Magen-Pouch die Anastomose oral und beim ileoanalen Pouch distal gelegen ist. Die Eigenmotilität des Pouches wird als mögliche Ursache schlechter funktioneller Ergebnisse diskutiert [4, 8, 9, 10]. Ziel der vorliegenden Studie war es deshalb, die Pouch-eigene Motilität isoliert unter standardisierten Bedingungen in Hinblick auf die Entwicklung einer Reservoirfunktion zu untersuchen und eventuelle funktionelle Unterschiede bezüglich der Position der Anastomose (oral — aboral) aufzuzeigen.

Der Abszeß wird üblicherweise als eine lokale Ansammlung von Entzündungszellen und liquifizierenden Gewebenekrosen in einem nicht präformierten Raum, der sich vom angrenzenden Gewebe durch eine Abszeßmembran pathomorphologisch abgrenzen läßt, beschrieben. Bei der Pathogenese der Abszedierung stehen in der Literatur v. a. ätiologische Gesichtspunkte im Vordergrund. Erst moderne Arbeiten haben die biophysikalischen Grundlagen der Abszeßpathologie erarbeitet. In einem tierexperimentellen Modell am Hausschwein konnte die besondere Rolle des Abszeßdrucks und anderer physikochemischer Parameter bei der systemischen Propagierung des zunächst lokal begrenzten Geschehens nachgewiesen werden. Durch eine artifizielle und initiale Anhebung des Abszeßdrucks auf 80 mmHg, der über einen Zeitraum von 6 h konstant gehalten wurde, konnte ein Temperaturanstieg auf über 38°C, ein Anstieg der Herzfrequenz sowie ein Abfall des mittleren arteriellen Drucks belegt werden. Der Anstieg von TNFα und IL-1 sowie der Nachweis positiver Blutkulturen unterstreichen die wichtige Rolle des Abszeßdrucks bei der Systemisierung der primär lokalen Infektion. Das traditionelle „Ubi pus ibi evacua“ gewinnt durch die vorliegende Untersuchung eine aktuelle, pathophysiologisch fundierte Bedeutung.

Abscess is customarily thought of as a collection of a large number of microorganisms, inflammatory cells and necrotic debris separated from the surrounding tissue by a fibrous capsule. Modern work focussed attention on more physico-chemical parameters in abscess pathogenesis. Recent experiences from animal models underline the impact of abscess pressure and bio-physicochemical parameters in the "abscess compartment" for systemic spreading. Artificial raising of abscess-pressure in pigs up to 80 mmHg was followed by increase of temperature and heartbeat rate and decrease of median arterial pressure. Elevated levels of TNF alpha, IL-1 and positive blood cultures support the theory of abscess pressure as a most important variable in abscess formation. We conclude that abscess pressure may play a pivotal role in systemic spreading of the primarily localized process.

Abscess is customarily thought of as a collection of a large number of microorganisms, inflammatory cells and necrotic debris separated from the surrounding tissue by a fibrous capsule. Modern work focussed attention on more physico-chemical parameters in abscess pathogenesis. Recent experiences from animal models underline the impact of abscess pressure and bio-physicochemical parameters in the "abscess compartement" for systemic spreading. Arteficial raising of abscess-pressure in pigs up to 80 mmHg was followed by increase of temperature and heartbeat rate and decrease of median arterial pressure. Elevated levels of TNF alpha, IL-1 and positive blood cultures support the theory of abscess pressure as a most important variable in abscess formation. We conclude that abscess pressure may play a pivotal role in systemic spreading of the primarily localized process.

Intestinale Mikrozirkulationsstörungen stellen in der Sepsis ein zentrales Diskussionskorrelat dar. Ungeklärt bleiben bislang die pathophysiologischen Wechselwirkungen zwischen Gastrointestinaltrakt, Sepsis und Übergang in ein Multiorganversagen. Ein qualitatives Monitoring des Intestinaltraktes ist bedingt mit der Elektromyographie und hinsichtlich der zellulären Integrität mit dem nichtinvasiven Monitoring der Kalium-Aktivität [1, 2, 3, 4] möglich. In einem standardisierten Modell sollte eine intestinale ”low flow state”-Situation differenziert untersucht werden, um weiterreichende Erkenntnisse über die Bedeutung des Darmes in der Sepsis zu erhalten.

We performed laparoscopy (n = 7) or laparotomy (n = 7) for exploration of the small intestine, cecal resection with Endo-GIA or TA-30, deserosation of 2 cm(2) of the abdominal wall and resection of the omentum majus in dogs. After 8 days all dogs were re-examined and the adhesions were quantified by computer-aided measurement. Laparoscopic operations were followed by significantly (P < 0.001) fewer adhesions. After conventional operations extensive adhesions to the abdominal incision and interenteric adhesions were found, together with frequent conglomerates of adhesions, intestinal kinkings or adhesive bands. identical manipulations, such as cecal resection or deserosation of the lateral abdominal wall, led to the same frequency and severity of adhesions in both groups. Based on our results, the risk of adhesion-related complications may be reduced by the laparoscopic approach.

An Hunden wurden laparoskopisch (n = 7) bzw. per Laparotomie (n = 7) nach Exploration des Dünndarms eine Zäkalpolresektion mit Endo-GIA bzw. TA-30 durchgeführt, 2 cm2 der lateralen Bauchwand deserosiert und ein Netzzipfel reseziert. Am B. postoperativen Tag wurden alle Tiere relaparotomiert und die entstandenen Adhäsionen rechnergestützt vermessen. Das Ausmaß der Adhäsionen nach laparoskopischen Eingriffen war signifikant (P < 0,01) geringer. Ausgedehnte Adhäsionen zur Laparotomiewunde und zwischen den Darmschlingen bedingten größere Adhäsionsflächen nach Laparotomie. Konglomeratadhäsionen, adhäsionsbedingte Darmabknickungen und Briden fanden sich häufiger nach konventionellen Operationen. Identische Manipulationen wie Zäkalresektion und Deserosierung der lateralen Bauchwand führten nach laparoskopischen und konventionellen Eingriffen zum gleichen Adhäsionsausmaß. Aufgrund unserer Ergebnisse ist das Risiko adhäsionsbedingter Komplikationen nach laparoskopischen Operationen insgesamt geringer als nach identischen konventionellen Eingriffen einzuschätzen.