Clinical review: Healing in gastrointestinal anastomoses, Part I

Incisionless revision of post-Roux-en-Y bypass stomal and pouch dilation: multicenter registry results

BACKGROUND

Surgical revision for weight regain after Roux-en-Y gastric bypass (RYGB) has been tempered by the high complication rates associated with standard approaches. Endoluminal revision of stoma and pouch dilation should intuitively confer a better risk profile. However, questions of clinical safety, durability, and weight loss need to be answered. We report our multicenter intraoperative experience and postoperative follow-up to date using the Incisionless Operating Platform for this patient subset.

METHODS

The patients who had regained significant weight >or=2 years after RYGB after losing >or=50% of excess body weight after RYGB were endoscopically screened for stomal and/or pouch dilation. Qualified patients underwent incisionless revision using the Incisionless Operating Platform to reduce the stoma and pouch size by placing anchors to create tissue plications. Data on the safety, intraoperative performance, postoperative weight loss, and anchor durability were recorded to date as a part of 2 years of postoperative follow-up.

RESULTS

A total of 116 consecutive patients were prospectively studied. Anchors were successfully placed in 112 (97%) of 116 patients, with an average intraoperative stoma diameter and pouch length reduction of 50% and 44%, respectively. The operating room time averaged 87 minutes. No significant complications occurred. At 6 months after the procedure (n = 96), an average of 32% of weight regain that had occurred after RYGB had been lost. The percentage of excess weight loss averaged 18%. The 12-month esophagogastroduodenoscopy results confirmed the presence of the anchors and durable tissue folds.

CONCLUSIONS

Incisionless revision of stoma and pouch dilation using the Incisionless Operating Platform can be performed safely. The data to date have demonstrated mild-to-moderate weight loss, and the early 12-month endoscopic images have confirmed anchor durability. Patients were actively followed up to document the long-term durability of this intervention in the entire patient subset.

Psychological stress and wound healing in humans: a systematic review and meta-analysis

OBJECTIVE

The current review aims to synthesize existing knowledge about the relationship between psychological stress and wound healing.

METHODS

A systematic search strategy was conducted using electronic databases to search for published articles up to the end of October 2007. The reference lists of retrieved articles were inspected for further studies and citation searches were conducted. In addition, a meta-analysis of a subset of studies was conducted to provide a quantitative estimation of the influence of stress on wound healing.

RESULTS

Twenty-two papers met the inclusion criteria of the systematic review and a subsample of 11 was included in a meta-analysis. The studies assessed the impact of stress on the healing of a variety of wound types in different contexts, including acute and chronic clinical wounds, experimentally created punch biopsy and blister wounds, and minor damage to the skin caused by tape stripping. Seventeen studies in the systematic review reported that stress was associated with impaired healing or dysregulation of a biomarker related to wound healing. The relationship between stress and wound healing estimated by the meta-analysis was r=-0.42 (95% CI=-0.51 to -0.32) (P<.01).

CONCLUSION

Attention now needs to be directed towards investigating potential moderators of the relationship, mediating mechanisms underpinning the association, as well as the demonstration of a causal link by the development of experimental interventions in healthy populations.

Ischemic preconditioning improves stability of intestinal anastomoses in rats

BACKGROUND

The aim of our study was to establish whether ischemic preconditioning (IPC) directly before performing a small bowel anastomosis has an effect on anastomotic stability and healing.

MATERIAL AND METHODS

Forty male Wistar rats were randomized to five groups: control (CO, n = 8) with preparation of the superior mesenteric artery (SMA) but without IPC. IPC groups had different intervals of ischemia (occlusion of the SMA) and reperfusion: 10 min ischemia and 20 min reperfusion (IPC10/20, n = 7), 10 min ischemia and 30 min reperfusion (IPC10/30, n = 8), 15 min ischemia and 20 min reperfusion (IPC15/20, n = 8), and 15 min ischemia and 30 min reperfusion (IPC15/30, n = 9). On the fourth postoperative day, the animals were relaparotomized: bursting pressure, hydroxyproline concentration, and histological ischemia mucosal injury scale of the anastomosis were assessed.

RESULTS

Four days after operation, the mean bursting pressure was 73 +/- 6 mmHg in the control group, whereas it was significantly higher in IPC10/20 (113 +/- 11 mmHg; p = 0.018), IPC10/30 (110 +/- 13 mmHg; p = 0.001), and IPC15/30 (124 +/- 9 mmHg; p = 0.003). IPC15/20 did not show a significant difference (63 +/- 2 mmHg; p = 0.4). We did not find a significant effect regarding hydroxyproline concentration, but IPC diminished mucosal injury.

CONCLUSIONS

IPC directly before performing a small bowel anastomosis has a time-dependent beneficial effect on anastomotic stability, thus indicating a new clinical approach to improve the healing process of intestinal anastomosis.

Impact of different crystalloid volume regimes on intestinal anastomotic stability

BACKGROUND

Anastomotic insufficiency still remains an unsolved problem in digestive surgery. Little clinical data, regarding the impact of perioperative volume management exist, which suggest lower complication rates in intestinal surgery under restrictive volume regimens. The aim of our study was to investigate the effect of the extent of intraoperative fluid administration with crystalloids on the stability of intestinal anastomoses.

MATERIAL AND METHODS

Twenty-one rats were randomly assigned to 3 experimental groups (n = 7 rats/group): control group CO (9 mL kg h crystalloid infusion), volume restriction group V (-) (3 mL kg h), and animals with volume overload V (+) (36 mL kg h). After midline incision, all animals received the corresponding infusion for a 30-minute period. Infusion was continued for further 30 minutes whereas an end-to-end small bowel anastomosis was performed 15 cm proximal to the Bauhin valve with 8 nonabsorbable interrupted inverting sutures. At reoperation on the 4th postoperative day, the anastomotic segment was dissected and the bursting pressure [mmHg] was measured. As a second parameter for the quality of anastomotic healing, hydroxyproline concentration was examined with a spectrophotometric method [microg/g dry tissue]. Histologically, structural changes of the anastomotic segments were assessed by 2 pathologists. Data are given as mean +/- SEM.

RESULTS

Anastomotic insufficiency was not seen in all animals. Bursting pressure of CO animals was 102 +/- 8 mmHg. Bursting pressure was lowest in V (+) with high volume exposure at 77 +/- 6 mmHg and significantly lower than V (-) (112 +/- 9 mmHg; P = 0.01) whereas the difference compared with the CO group did not reach significant values. Hydroxyproline concentration in V (+) (64.4 microg/g dry tissue +/- 7.7) was significantly lower compared with V (-) (91.7 microg/g dry tissue +/- 9.1) animals (P < 0.05). In all animals with volume overload a marked submucosal edema was found.

CONCLUSION

We could demonstrate for the first time in a systematic investigation, that the quantity of crystalloid infusion, applied intraoperatively, has a significant impact on functional (bursting pressure) and structural (hydroxyproline) stability of intestinal anastomoses in the early postoperative period. Because the stability and quality of an intestinal anastomosis have an impact on insufficiency rates, it should be noted that volume overload may have deleterious effects on anastomotic healing and postoperative complications in digestive surgery, possibly because of a marked bowel wall edema.

Circular 'superelastic' compression anastomosis: from the animal lab to clinical practice

The recent development of a compression device using shape memory Nitinol technology to create an end-to-end anastomosis has renewed the interest in sutureless anastomotic techniques. A phase II, prospective open label clinical trial was started in May 2007 to evaluate the feasibility and safety of this new anastomotic device. Fourty patients who need left colectomy or high anterior resection for either diverticular disease or adenocarcinoma will be recruited in two academic hospitals (Uppsala,Sweden and Leuven, Belgium). Clinical leakage is the primary endpoint. Only preliminary results are available to date as the recruitment is ongoing. The median age of the first ten patients is 57.5 years (44-72). No anastomotic leakage occurred. The median hospital stay was 4.0 days. Only three patients noticed the passage of the ring through the anal canal. By three weeks no ring was sustained in the gastrointestinal tract as was objectified by plain X-ray. First clinical use of this new anastomotic device seems promising. Final results for the total phase II trial are awaited. A prospective randomized trial to compare the efficacy of the EndoCar 28 with conventional stapling should be the next step.

Adipose-derived mesenchymal stem cells in biosutures do not improve healing of experimental colonic anastomoses

BACKGROUND

The feasibility of producing 'biosutures' coated with adipose-derived mesenchymal stem cells (ASCs) was assessed and their effect on colonic anastomoses evaluated.

METHODS

Sutures were cultured with ASCs isolated from BDIX rats before analysis by light and scanning electron microscopy. Anastomoses were performed in 40 BDIX rats using either biosutures or conventional sutures. Histopathological features, adhesion formation and anastomotic strength were evaluated.

RESULTS

Sutures were coated with ASCs within 24 h. Anastomoses made with biosutures had a lower adhesion index only during the first week (P = 0.006 at 7 days), but not subsequently. There were no significant differences in anastomotic healing with the two types of suture.

CONCLUSION

ASC biosutures have no effect on anastomotic healing in rats.

Ultrastructural view of colon anastomosis under propolis effect by transmission electron microscopy

AIM: To evaluate the effect of propolis administration on the healing of colon anastomosis with light and transmission electron microscopes.

METHODS: Forty-eight Wistar-Albino female rats were divided into two groups and had colon resection and anastomosis. In group I, rats were fed with standard rat chow pre- and postoperatively. The rats in group II were fed with standard rat chow and began receiving oral supplementation of propolis 100 mg/kg per day beginning 7 d before the operation and continued until they were sacrificed. Rats were sacrificed 1, 3, 7 and 14 d after operation, and anastomotic bursting pressures measured. After the resection of anastomotic segments, histopathological examination was performed with light and transmission electron microscopes by two blinded histologists and photographed.

RESULTS: The colonic bursting pressures of the propolis group were statistically significantly better than the control group. Ultrastructural histopathological analysis of the colon anastomosis revealed that propolis accelerated the phases of the healing process and stimulated mature granulation tissue formation and collagen synthesis of fibroblasts.

CONCLUSION: Bursting pressure measurements and ultra structural histopathological evaluation showed that administration of propolis accelerated the healing of colon anastomosis following surgical excision.