Suture-Free Small Bowel Anastomoses Using Collagen Fleece Covered with Fibrin Glue in Pigs

Background: Several studies investigating anastomotic healing could objectify that the regularly used suture material leads to an impairment of wound healing due to ischemia at the anastomotic line. This study was initiated to test a hypothesis that a reduction of suture material leading to suture-free glued intestinal anastomoses is feasible and enables an improved wound healing. Materials and Methods: Three different types of anastomoses were carried out at the small bowel of 16 pigs. Standard hand-sewn anastomoses, anastomoses with loose-fitting skin staples, and suture-free glued anastomoses using a fibrin covered collagen fleece. When the animals were killed, both gross inspection of the parietes, bursting pressure and tissue for histological study became the basis for evaluation. Analyses were also made regarding the collagen I/III ratio and the expression of MMP 1 and 13. Results: Four leakages at the stapled, one at the sutured, and one at the glued anastomoses occurred. All other anastomoses healed without complications. The bursting pressure did not differ significantly between the groups. The macroscopic inspection and the microscopic examination both showed an improved healing pattern for the material reduced techniques without onset of a deep ulcer at the anastomotic line as seen at the conventional sutured anastomoses. These findings were supported by the immunohistochemical studies. Conclusions: These observations suggest that a suture-free bowel anastomoses using collagen fleece covered with fibrin glue is technically feasible. Obviously, a reduction of foreign body material at the anastomotic line avoids unnecessary ischemia and thus supports a physiological improved wound healing process.     

Combination of Fibrin Glue with Growth Hormone Augments Healing of Incomplete Intestinal Anastomoses in a Rat Model of Intra-Abdominal Sepsis: A Dynamic Study

This study was devised to investigate whether fibrin glue (FG) in combination with growth hormone (GH) could have a beneficial effect at a late period (14 days) after injury. Male Wistar rats, with abdominal sepsis induced by an incomplete anastomosis, were divided into three groups. In the control group, the rats got incomplete anastomoses sutured alone; in the FG and FG/GH groups, anastomoses protection was performed with application of FG alone or in combination with GH. The anastomotic bursting pressure (ABP) was significantly higher in the FG/GH group than that of the FG group on postoperative day (POD) 5 (p <. 01), while it could not be measured from POD 7 to POD 14 because of intestinal dehiscence. There was no difference between FG and FG/GH group on POD 3 and POD 5 in anastomotic tensile strength, which was significantly higher in the FG/GH group than that of the FG group from POD 7 to POD 14 (p <. 001). Hydroxyproline content of the FG/GH group was significantly higher than that of the control from POD 3 and that of the FG group from POD 5 (p <. 05). Combination of FG with GH had a synergistic effect to improve intestinal anastomotic healing over a limited 14-day course of observation.     

The Pig as an Experimental Model for Colonic Healing Study of Leakage and Ischemia in Colonic Anastomosis

Background: The object of this experimental study was to develop a model of anastomotic failure due to primary leakage and ischemia in porcine large bowel anastomosis. Methods: End-to-end anastomosis was constructed at descending colon in 12 pigs. The pigs were randomly divided into three groups. In Group A, the anastomosis was applied with a leak of 18 mm. In Group B, in addition to primary leakage, an artificial ischemia of the proximal anastomotic bowel segment was created by ligation of supplying vessels over 5 cm. In Group C, an artificial ischemia was created in the same manner at the proximal and distal anastomotic segment and the anastomosis was applied with an intentional leakage as in Groups A and B. The animals were sacrificed immediately in case of clinical signs of anastomotic dehiscence, sepsis, peritonitis, or ileus. The animals were sacrificed on day 28. The peritoneal cavity was examined for peritonitis, anastomotic wound dehiscence, and pericolic abscess formation. Results: Distinct fibrinous coverings and adhesions at the anastomotic area were found in all animals. In cases of primary leakage without ischemia, only one of the four animals developed abscess at anastomotic side with clinical sepsis. In cases of primary leakage with ischemia of the proximal anastomotic bowel segment, one of the four animals presented generalized peritonitis with sepsis. In Group C, there were no signs of leakage or peritonitis, although three of the four animals developed colonic ileus due to obturation of the colonic lumen by a clot of necrotic bowel wall. Conclusion: Large anastomotic dehiscence and local ischemia of the bowel wall are not reliable factors for the development of intra-abdominal abscess, peritonitis, or sepsis in the pig model.     

Effect of Bioactive Polypeptides on Leaking Large Bowel Anastomosis and Intestines in the Rat

Anastomotic leakage and postoperative adhesions represent major complications after colorectal surgery. We have previously shown a positive effect on both anastomotic strength and abdominal adhesions by the use of differently charged bioactive polypeptides. The present study aimed to investigate the effect of the same polypeptides on the healing of an insufficient intestinal anastomosis, as well as on accidental intestinal injury, in addition to measuring the preventive effect against the development of abdominal adhesions. An insufficient, and thereby potentially leaking, intestinal anastomosis and punctures of the intestine (“accidental intestinal injury model”) were performed in rats. The treatment groups received intraperitoneal administration of poly-L-lysine and poly-L-glutamate, while controls received sodium chloride. Burst pressure, extent of abdominal adhesions, and postoperative complications were analyzed in both experimental models. A significant decrease of adhesions was seen in all animals treated with polypeptides (p <. 05). Burst pressure was significantly higher (p <. 001) in animals with intestinal perforation as seen on day 1 and then decreasing. A significant decrease in the incidence of peritonitis was also noted early (day 1) in this model (p =. 002). The mortality and complications were high in the intestinal anastomosis model, though not affected by treatment with polypeptides. Intraabdominal adhesions were significantly reduced using polypeptides in this study, with no observed effect on other postsurgical complications. There were signs of less infectious complications in polypeptide treated animals. In animals with accidental intestinal injury, a higher burst pressure was noted in treated animals.     

Innovation and Change in Medical Technology: Interactions Between Physicians and Engineers

Intraperitoneal adhesions following surgical procedures cause considerable morbidity. Hyaluronic acid/carboxymethylcellulose (HA/CMC) films have been shown to be effective agents in decreasing adhesion formation. However, when there is an inadvertent leak of bowel contents into the peritoneum due to incomplete anastomosis, adhesion formation about a defect in order to prevent further leakage and to promote healing of the wound is important for the prevention of morbidity and mortality. The purpose of this study was to determine if an antiadhesion film (HA/CMC) impairs these potentially beneficial adhesions to bowel anastomoses, thus predisposing them to enteric leaks with subsequent peritonitis. Sixty-four rabbits were divided in two groups, each undergoing a complete or partial (90% anastomosis to simulate anastomotic leak) large bowel anastomosis. Half of each of the above groups were treated by wrapping a HNCMC film over the anastomosis and the other half were untreated controls. These two subgroups were then further divided equally and sacrificed at either 7 or 14 days for evaluation of anastomosis integrity and strength. The average anastomtic bursting pressures did not change significantly between those groups treated with HMCMC when compared to untreated controls at 7 or 14 days or in the complete or partial anastomosis group (Student's t test). Adhesion formation to the anastomosis was not impaired in either group independent of HAKMC film application. This study suggests that while HA/CMC film has been shown to decrease adhesions in other models, healing of u rabbit colonic unastomosis even in the presence of an anastomotic defect takes place, further suggesting that the stimulus for adhesion formation can overcome the antiadhesion properties of HA/CMC. Therefore, HA/CMC is a potentially safe adjuvant for preventing postoperative intraabdominal adhesions.     

低功率He-Ne激光照射对兔骨折愈合影响的实验研究

为探讨He-Ne激光对骨折愈合的作用,本实验用43只新西兰兔行桡骨中段截骨作为实验模型,用JG-I型医用He-Ne激光机照射骨折局部,同体对照,左侧为照射侧,右侧为对照侧,照射功率密度11.3mW/cm~2,光斑直径1.5cm,每天一次,每次10min,对照侧不作任何处理,10～60d取标本,通过X线摄片,组织学检查观察低功率,He-Ne激光照射对兔骨折愈合的影响。实验结果表明,在骨愈合的前40d,低功率He-Ne激光照射能明显促进兔新鲜骨折愈合。认为低功率He-Ne激光照射能促进骨折处血肿机化;骨折端血循环重建;加快软骨内化骨的进程;加速骨痂组织中钙盐沉积。     

Small Intestinal Submucosa as a Vascular Graft: A Review

Continuing investigations of vascular graft materials suggest that unacceptable graft complications continue and that the ideal graft material has not yet been found. We have developed and tested a biologic vascular graft material, small intestine submucosa (SIS), in normal dogs. This material, when used as an autograft, allograft, or xenograft has demonstrated biocompatibility and high patency rates in aorta, carotid and femoral arteries, and superior vena cava locations. The grafts are completely endothelialized at 28 days post-implantation. At 90 days, the grafts are histologically similar to normal arteries and veins and contain a smooth muscle media and a dense fibrous connective tissue adventita. Follow-up periods of up to 5 years found no evidence of infection, intimal hyperplasia, or aneurysmal dilation. One infection-challenge study suggested that SIS may be infection resistant, possibly because of early capillary penetration of the SIS (2 to 4 days after implantation) and delivery of body defenses to the local site. We conclude that SIS is a suitable blood interface material and is worthy of continued investigation. It may serve as a structural framework for the application of tissue engineering technologies in the development of the elusive ideal vascular graft material.     

疝环充填式与平片式无张力疝修补术治疗腹股沟疝的临床比较研究

目的：比较疝环充填式与平片式无张力疝修补术治疗成人腹股沟疝的临床疗效。方法：随机将135例腹股沟疝病人分为疝环充填式组和平片式组，分析比较两组的临床及随访资料。结果：两组在手术时间，术后早期疼痛，导尿率，体温，并发症，平均住院日及术后复发率等方面无明显差异。结论：疝环充填式与平片式无张力疝修补术治疗成人腹股沟疝总的治疗效果相近。     

Predicting Intestinal Ischaemia in Patients with Adhesive Small Bowel Obstruction: A Simple Score

World Journal of Surgery - Intestinal ischaemia (II) is the most critical factor to determine in patients with adhesive small bowel obstruction (ASBO) because intestinal ischaemia could be...     

Intrathecal Ropivacaine in Rabbits: Pharmacodynamic and Neurotoxicologic Study

Background: Ropivacaine is available for spinal or intrathecal use in humans, although data on neurotoxicity after spinal injection are not yet available. The authors experimentally determined the relationship between doses of intrathecal ropivacaine and spinal effects and local neurotoxic effects.

Methods: Eighty rabbits equipped with an intrathecal lumbar catheter were studied. Sixty were randomly assigned to receive 0.2 ml of intrathecal solutions as a sole injection of: 0.2%, 0.75%, 1.0%, and 2.0% ropivacaine (doses from 0.4-4.0 mg; groups R0.2 to R2.0), 5.0% lidocaine (10 mg; group L), or 0.9% NaCl as control (group C). Twenty other rabbits received either repeated injections of 0.2 ml of 0.2% ropivacaine every 2 days during 2 weeks (total dose of 2.8 mg; group RINT); or a continuous intrathecal infusion of 0.2% ropivacaine at the rate of 1.8 ml/h over 45 min (2.7 mg; group RCONT). Injection rate was 30 s in all groups except Rcont. Time to onset, duration and extent of motor block, and variations of mean arterial blood pressure were recorded in all groups. Somatosensory evoked potentials were also recorded in group RCONT and RINT. Seven days after the last intrathecal injection spinal cord and nerves were sampled for histopathologic study.

Results: In groups R0.2 and RINT, the lowest dose of ropivacaine induced a clinically visible spinal block in only 50% of rabbits, but SEPs recorded in group RINT were decreased by 70% in the lumbar dermatome. Complete motor block was observed with doses greater than 1.5 mg of ropivacaine (group RCONT and R0.75 to R2.0). Onset time was shorter and duration of block increased as doses of ropivacaine increased. Significant hypotension was observed only with 4.0 mg of ropivacaine (concentration of 2.0%). Complete paralysis and hypotension were observed with 5.0% lidocaine. No neurologic clinical lesion was observed in rabbits receiving saline or ropivacaine within the 7 days after the last intrathecal injection, and histopathologic study revealed no sign of neurotoxicity in these groups. In contrast, intrathecal lidocaine induced clinical and histopathologic changes.     

Small animal bone healing models: standards, tips, and pitfalls results of a consensus meeting

Small animal fracture models have gained increasing interest in fracture healing studies. To achieve standardized and defined study conditions, various variables must be carefully controlled when designing fracture healing experiments in mice or rats. The strain, age and sex of the animals may influence the process of fracture healing. Furthermore, the choice of the fracture fixation technique depends on the questions addressed, whereby intra- and extramedullary implants as well as open and closed surgical approaches may be considered. During the last few years, a variety of different, highly sophisticated implants for fracture fixation in small animals have been developed. Rigid fixation with locking plates or external fixators results in predominantly intramembranous healing in both mice and rats. Locking plates, external fixators, intramedullary screws, the locking nail and the pin-clip device allow different degrees of stability resulting in various amounts of endochondral and intramembranous healing. The use of common pins that do not provide rotational and axial stability during fracture stabilization should be discouraged in the future. Analyses should include at least biomechanical and histological evaluations, even if the focus of the study is directed towards the elucidation of molecular mechanisms of fracture healing using the largely available spectrum of antibodies and gene-targeted animals to study molecular mechanisms of fracture healing. This review discusses distinct requirements for the experimental setups as well as the advantages and pitfalls of the different fixation techniques in rats and mice.     

The Vascularization in the Amputation Stumps of Rabbits: A Microangiographic Study

With the aid of microangiography the vascularization in the amputation stumps of 108 rabbits was studied, both in extremities with normal circulation and in those supplied with collaterals. It was found that the vascularization of the normal leg was altered by amputation, with the development of newly-formed, pathological, spirally-twisted vessels. Closure of the stump with myoplasty, however, counteracted this vessel formation, and hypervascularization took place through normal arteries. After amputation of extremities supplied with collaterals, the influence of amputation on collateral function and vascularization in the amputation stump was dependent on the time interval between arterial occlusion and amputation.     

Lower Reoperation Rate for Recurrence after Mesh versus Sutured Elective Repair in Small Umbilical and Epigastric Hernias. A Nationwide Register Study

Background

Repair for a small (≤2 cm) umbilical and epigastric hernia is a minor surgical procedure. The most common surgical repair techniques are a sutured repair or a repair with mesh reinforcement. However, the optimal repair technique with regard to risk of reoperation for recurrence is not well documented. The aim of the present study was in a nationwide setup to investigate the reoperation rate for recurrence after small open umbilical and epigastric hernia repairs using either sutured or mesh repair.

Materials and methods

This was a prospective cohort study based on intraoperative registrations from the Danish Ventral Hernia Database (DVHD) of patients undergoing elective open mesh and sutured repair for small (≤2 cm) umbilical and epigastric hernias. Patients were included during a 4-year study period. A complete follow-up was obtained by combining intraoperative data from the DVHD with data from the Danish National Patient Register. The cumulative reoperation rates were obtained using cumulative incidence plot and compared with the log rank test.

Results and conclusions

In total, 4,786 small (≤2 cm) elective open umbilical and epigastric hernia repairs were included. Age was median 48 years (range 18–95 years). Follow-up was 21 months (range 0–47 months). The cumulated reoperation rates for recurrence were 2.2 % for mesh reinforcement and 5.6 % for sutured repair (P = 0.001). The overall cumulated reoperation rate for sutured and mesh repairs was 4.8 %. In conclusion, reoperation rate for recurrence for small umbilical and epigastric hernias was significantly lower after mesh repair compared with sutured repair. Mesh reinforcement should be routine in even small umbilical or epigastric hernias to lower the risk of reoperation for recurrence avoid recurrence.     

Cytomegalovirus Infection Management in Multivisceral and Intestinal Transplant: A Dual Institution Study

Intestinal transplant and multivisceral transplant were originally in pediatric populations and are relatively new procedures in adults. Despite increasing success rates in the immediate post-transplant period, infectious complications and acute and chronic rejection remain significant causes of morbidity and mortality. Previous research has shown cytomegalovirus (CMV) is the main cause of infection in this population. Due to the limited patient population, incidence of CMV viremia ranges widely and there is lack of universal protocol for treatment. This dual institution retrospective chart review between Henry Ford Hospital and Duke University analyzed adult intestinal and multivisceral transplant recipients between 2009 and 2019. Of the 32 patients identified and included in the study, 15 had CMV infection (46.9%). Of those with CMV infection, 5 (33.3%) had donor positive (D+)/recipient positive (R+) status; 5 had D-/R+; 4 had D+/R-; and one had D-/R-. There was no significant difference between mortality in those who had reported infection and not (80% vs 76.5%). The data from this study show significant rates of CMV viremia in patients undergoing intestinal transplant/multivisceral transplant with almost half of our study population having documented infection within 1 year of transplant, stressing the importance for universal protocol into CMV viremia treatment.     

Regional Blood Flow in Experimental Myositis Ossificans: A Microsphere Study in Conscious Rabbits

In a recent model for heterotopic bone formation (Michelsson et al. 1980), muscular oedema, swelling and necrosis is seen in the quadriceps muscle of rabbit hind limbs immobilized for at least 2 weeks when, from the second week, the immobilized limb is subjected to daily forcible mobilization lasting about 5 min. According to this model, heterotopic calcification develops gradually from the second week of forcible mobilization and is located in the vastus intermedins region. Between the fourth and fifth week of immobilization and forcible mobilization, heterotopic bone formation is seen in virtually all cases. The histological findings are similar to those in human ectopic bone formation.

In the present investigation the labelled microsphere technique was used to study the regional blood flow effects in the early development of myositis ossificans with this model. The results are quite different from those reported by other investigators on immobilization alone and point to a causal relation between regional blood flow and forcible mobilization of the immobilized rabbit hind limb. Prostaglandins as mediators between the traumatic inflammation, a part of the circulatory effects observed and the induction of new bone is suggested.