[Anastomotic leakage in the gastrointestinal tract-repair and prognosis]

Surgical sutures: coincidence or experience?

BACKGROUND

Knotting sutures by hand is still important in daily surgical routine, especially laparotomy closure. The expectation is that hand suturing relies on the experience and subjective estimation of the surgeon. The aim of this study was to investigate whether hand suturing tension is reproducible and if surgical experience influences reproducibility.

METHODS

At the annual Congress of the German Association of Surgery, 118 surgeons performed repetitive sutures on a standardized and certified measuring device simulating the final knot of a fascial closure. Each surgeon was asked to perform five identical single knots in a row using the suture tension that each considered ideal. Tension during knotting was measured in Newtons. The surgeons were divided into five subgroups based on surgical experience: group 1, <1 year; group 2, 2-5 years; group 3, 6-10 years; group 4, 11-20 years; and group 5, >30 years.

RESULTS

The tension measured at the end of knotting ranged from 0.19 to 10 N. The mean suture tension at endpoint was 3.88 N for group 1 and slightly higher in the other groups, but not significantly different. The overall mean suture tension was 5.43 N and did not correlate with surgical experience. Suture tension was not reproducible.

CONCLUSION

Sequential suture tension varied, even among experienced surgeons. The ideal tissue-dependent suture tension has not been defined. Measured values appear to be intuitive, relying on individual feeling rather than the level of experience.

Effects of a Glutamine Enema on Anastomotic Healing in an Animal Colon Anastomosis Model

PURPOSE

Anastomotic leakage in colorectal surgery is a very important issue. Although many studies have shown the positive effects of enteral glutamine (Gln) on anastomotic healing, none has assessed the effects of administering Gln via an enema for anastomotic healing. To fill this study gap, this study investigated the intraluminal effect of administration of Gln enema on the healing of colonic anastomosis in a rat model.

METHODS

Thirty Wistar albino rats were divided into three groups containing 10 rats each and were subjected to distal left colon transection and anastomosis. Postoperatively, group I (the control group) was administered no treatment, group II was administered daily placebo enemas containing physiological saline, and group III was administered daily 2% L-Gln enemas. After sacrifice on postoperative day 5, anastomotic healing, burst pressure, tissue hydroxyproline levels, and histological parameters were measured, and group values were compared via statistical analysis.

RESULTS

Group III was found to have the highest mean bursting pressure and tissue hydroxyproline levels and the lowest mean ischemia score. While the values of these parameters were not found to differ significantly among the groups, the lack of significance may have been due to the limited number of subjects examined.

CONCLUSION

Administration of a Gln enema may have a positive effect on anastomosis in terms of bursting pressure and histopathological parameters. Future research should examine administration of a preoperative Gln enema as a means of decreasing the traumatic effects of the enema and identifying its applicability in surgical practice.

Vascular anatomy of the small intestine-a comparative anatomic study on humans and pigs

BACKGROUND

Porcine models are well established for studying intestinal anastomotic healing. In this study, we aimed to clarify the anatomic differences between human and porcine small intestines. Additionally, we investigated the influences of longitudinal and circular sutures on human small intestine perfusion.

METHODS

Intestines were obtained from human cadavers (n = 8; small intestine, n = 51) and from pigs (n = 10; small intestine, n = 60). Vascularization was visualized with mennige gelatin perfusion and high-resolution mammography. Endothelial cell density was analyzed with immunohistochemistry and factor VIII antibodies. We also investigated the influence of suture techniques (circular anastomoses, n = 19; longitudinal sutures, n = 15) on vascular perfusion.

RESULTS

Only human samples showed branching of mesenteric vessels. Compared to the pig, human vessels showed closer connections at the entrance to the bowel wall (p = 0.045) and higher numbers of intramural anastomoses (p < 0.001). Porcine main vessels formed in multifilament-like vessel bundles and displayed few intramural vessel anastomoses. Circular anastomoses induced a circular perfusion defect at the bowel wall; longitudinal anastomoses induced significantly smaller perfusion defects (p < 0.001). Both species showed higher vascular density in the jejunum than in the ileum (p < 0.001). Human samples showed similar vascular density within the jejunum (p = 0.583) and higher density in the ileum (p < 0.001) compared to pig samples.

CONCLUSION

The results showed significant differences between human and porcine intestines. The porcine model remains the standard for studies on anastomotic healing because it is currently the only viable model for studying anastomosis and wound healing. Nevertheless, scientific interpretations must consider the anatomic differences between humans and porcine intestines.

[Anastomotic techniques for the gastrointestinal tract]

The correct suture technique for anastomoses of the gastrointestinal (GI) tract is a major task in the daily practice of surgery and a basic requirement for a successful operation. This article provides an overview of the surgical principles and techniques involved in the creation of intestinal anastomoses, including the differentiated use of various suturing aids in the GI tract. Hand sewn and stapled anastomotic techniques are illustrated and discussed. The ongoing discussion and question as to which technique is best for GI anastomoses remains unanswered as there is no obligatory standard, even though the requirements are well defined. An ideal anastomosis should fulfil the following criteria: it must be well vascularized, safe, tension-free and spillage from the operation field should be avoided.

The application of the V-Loc closure device for gastrointestinal sutures: a preliminary study

BACKGROUND

Leakage is one of the major complications in gastrointestinal surgery. This preliminary study compared a new barbed absorbable thread for gastrointestinal sutures with monofil suture material in a cadaver model.

METHODS

In this study, mechanical experiments were performed in 20 recently deceased individuals. Incisions were made in the small intestine, colon, and stomach, and then sutures were created with the V-Loc closure device and monofil suture material. Intestinal bursting pressure was measured by inserting a balloon and slowly filling it with air until there was a dehiscence, or wall or suture rupture.

RESULTS

The bursting pressures differed significantly between the two sutures in the small intestine, showing the advantage of the V-Loc closure device, which had a mean bursting pressure of 116.2 mmHg compared with 110 mmHg for the monofil suture (p = 0.003). The mean bursting pressure did not differ significantly between the two sutures in the colon and the stomach. The mean bursting pressures for the V-Loc closure device were 141.3 mmHg (stomach) and 137.2 mmHg (colon) compared with the monofil suture material bursting pressures of 133 mmHg (stomach) and 134.8 mmHg (colon).

CONCLUSIONS

Because the bursting strength of the sutures created with monofil suture material differs significantly from that of the V-Loc closure device, the V-Loc suture material should be used for gastrointestinal sutures. Although the two sutures did not differ significantly in the colon or the stomach, the V-Loc closure device should be used for these as well because its advantages may overrule those of the monofil suture. No knot tying is required, and the operating time can be shorter. Especially for laparoscopic surgery, the V-Loc closure device is recommended.

Effects of thyroid hormone supplementation on anastomotic healing after segmental colonic resection

BACKGROUND

Alterations of thyroid hormones in colorectal surgery were previously studied. The aim of the present study was to determine the effects of triiodothyronine (T3) supplementation on anastomotic healing after segmental colectomy.

MATERIAL AND METHODS

Thirty male Wistar albino rats were divided into sham (n = 6), control (n = 12), and experimental (n = 12) groups. Sham group rats were immediately sacrificed after segmental colonic resection. Control and experimental group rats underwent resection and anastomosis. Experimental group rats received a single dose of T3 (400 μg/100 g) in postoperative day 1. Half of both control and experimental group rats were sacrificed on postoperative d 3 and the remaining half were sacrificed on postoperative d 7. Hydroxiproline (HP), myeloperoxidase (MPO), thyroid stimulating hormone (TSH), free T3 (FT3), and free thyroxine (FT4) levels, bursting pressure, and histologic analyses of the anastomotic segments were compared.

RESULTS

FT3 levels significantly decreased in control groups rats compared with the sham group (P < 0.01). However, T3 hormone given rats had no decline in FT3 levels. Anastomotic bursting pressure was significantly higher in the experimental group rats on postoperative d 7 (P = 0.015). Histopathologic analyses of the anastomotic segments determined significantly more severe edema and necrosis in control group rats (P < 0.05). Collagen deposition in the anastomotic tissue was significantly higher in experimental group rats on postoperative d 7 (P = 0.015).

CONCLUSION

Anastomosis after colon resection is associated with decreased FT3 level. T3 supplementation ameliorates the reduction in FT3 and seems to provide constructive therapeutic effects on anastomotic healing.

[Intestinal anastomoses and techniques in the lower gastrointestinal tract]

Surgery of the lower gastrointestinal tract includes segmental resections for benign colorectal diseases and radical resections for treating colorectal cancer performed under elective and emergency conditions. The most important part of the surgical procedure is the reconstruction of the physiological intestinal continuity by anastomosis. At present laparoscopic surgery has widened the array of different suturing and stapling techniques. The effectiveness of manual and stapled anastomoses depends on the expertise of the surgeon. However, skillful preparation of the hand-sutured technique is essential.

Collagen in colon disease

The pathophysiology of wound healing in the bowel wall suggests that collagen and matrix metalloproteinases (MMPs) have an important role in the changes of the bowel wall seen in several colonic diseases. Several recent studies suggest that disturbances of the collagen texture and the extracellular matrix (ECM) metabolism are major factors leading to the onset of diverticular disease. Changes of the ECM also play a role in the development of inflammatory bowel diseases. Regarding the permanent remodeling of the bowel wall, any imbalance of the ECM could support the onset of chronic inflammation and the development of fistula formation, such as that seen in patients with Crohn's disease. Disturbances of the ECM play a role in the pathogenesis of anastomotic leakage after large bowel surgery and suggest the presence of a genetically defined risk population with disturbed wound healing mechanisms. This concept could explain the well known situation where an anastomotic breakdown is observed, despite the absence of other known risk factors and after a technically correct anastomosis.