Healing in the gastrointestinal tract

[A prospective, randomised, controlled study on the need to mechanically prepare the colon in scheduled colorectal surgery]

INTRODUCTION

Mechanical preparation of the colon (MPC) in colorectal surgery has been a dogma that has been questioned over the last few years. The objective of this study is to demonstrate that morbidity in scheduled colorectal surgery is the same or lower without MPC.

MATERIAL AND METHOD

Patients subjected to scheduled left colon and rectal surgery with primary anastomosis randomised into two groups. The "Preparation" group (MPC) received MPC and the "non-preparation" group (No-MPC) had only cleaning enemas. The variables collected were: demographic, oncological, nutritional, risk prediction models and morbidity-mortality.

RESULTS

Of the 193 patients included: 69 received MPC and 71 did not; 89 patients with colocolic anastomosis (MPC, 38; no MPC, 51) and 50 colorectal (MPC, 31; no MPC, 19). Statistically significant differences were seen in the overall analysis in favour of "no preparation" as regards morbidity (43.55 % with MPC and 27% with No MPC) and nosocomial infection (27.5% and 11.4%). There was 11.6% wound infections in the MPC compared to 5.7% in the no MPC, which was not statistically significant. The only mortalities were in the MPC group 2/69 (2.9% of patients). As regards the location of the anastomosis, in the colocolics the differences were more pronounced, with statistically significant differences in the morbidity, anastomosis dehiscence, and nosocomial infection variables. The effect of no MPC was not so evident in colorectal anastomosis.

CONCLUSIONS

Our results suggest that there is no benefit in MPC before surgery in colocolic anastomosis. No-MPC is not associated with a higher morbidity in wound infection or anastomotic dehiscence. In colorectal anastomosis the differences are not so evident, therefore a much bigger series needs to be studied.

Effects of amniotic membrane on the healing of primary colonic anastomoses in the cecal ligation and puncture model of secondary peritonitis in rats

PURPOSE

We aimed to investigate the effects of amniotic membrane on primary colonic anastomoses in a rat peritonitis model.

MATERIALS AND METHODS

Fifty female Sprague Dawley rats were used in the study. Bacterial peritonitis was induced in all rats by performing a cecal ligation and puncture. Ten rats served as controls for the bursting pressure measurement, while the other 40 animals were divided into two groups (the anastomosis group (P) or the amniotic membrane group (PA)), and all of them underwent colonic anastomosis. The latter group had amniotic membrane covering their anastomoses. Half of the PA and P groups were sacrificed on the third postoperative day (PA3, P3), and the other half on the seventh postoperative day (PA7, P7).

RESULTS

The bursting pressures were significantly higher in groups PA3 and PA7 compared with P3 (p < 0.01) and P7 (p < 0.05), respectively. Inflammatory cell infiltration and adhesion scores were significantly lower in groups PA3 and PA7 compared with groups P3 (p < 0.001, p < 0.01, respectively) and P7 (p < 0.001, p < 0.05, respectively). Neoangiogenesis, fibroblast activity, collagen deposition, and hydroxyproline concentrations were significantly higher in groups with amniotic membrane than in groups without amniotic membrane (p < 0.05, for all comparisons).

CONCLUSION

This study showed that the covering of colonic anastomoses with amniotic membrane significantly prevented the delaying effect of intraperitoneal sepsis and provided a safer and stronger anastomosis than suture and that this was the case for both the early and late phases of anastomotic healing in the colon.

The effect of calcitonin gene-related peptide on healing of intestinal anastomosis in rats with experimental obstructive jaundice

PURPOSE

Intestinal anastomotic healing is a complex procedure in which several mediators and cytokines play roles. Calcitonin gene-related peptide is an important neuropeptide in inflammation. In this study we aimed to investigate the effect of calcitonin gene-related peptide on healing of intestinal anastomosis in rats with obstructive jaundice.

MATERIALS AND METHODS

Obstructive jaundice was induced in rats by the ligation and division of the common bile duct. Four days after the operation, intestinal anastomosis was performed, and either calcitonin gene-related peptide or 0.9% NaCl was administered intraperitoneally to these jaundiced rats and controls. The concentrations of serum tumor necrosis factor-alpha (TNF-alpha) and triglyceride levels of all rats were measured, and healing of the anastomosis was evaluated by measuring the bursting pressure and hydroxyproline content on the 7th postoperative day.

RESULTS

Calcitonin gene-related peptide was found to have positive effects on healing of the anastomosis by inhibiting the effects of TNF-alpha and increasing the bursting pressure and hydroxyproline content of the anastomosis.

CONCLUSION

Calcitonin gene-related peptide increases anastomotic wound healing in experimental anastomosis in the presence of obstructive jaundice in rats.

Is the use of cyanoacrylate in intestinal anastomosis a good and reliable alternative?

PURPOSE

The present study aims to compare strength, healing, and operation time of experimental intestinal anastomoses performed by polyglactin 910 (Vicryl; Ethicon, Edinburgh, United Kingdom) sutures with ethyl-2-cyanoacrylate glue (Pattex; Henkel, Dusseldorf, Germany).

MATERIAL AND METHODS

Ninety-six Sprague-Dawley rats were divided into 2 (groups E and L). Each group was further subdivided into 6 subgroups (EA1, EA2, EA3, EB1, EB2, EB3, LA1, LA2, LA3, LB1, LB2, LB3), each containing 8 rats. Intestinal anastomosis was performed by polyglactin 910 sutures in A subgroups and with ethyl-2-cyanoacrylate in B subgroups. The anastomosis was end to end in A1 and B1, side to side in A2 and B2, and end to side in A3 and B3. Time for anastomosis performance (AT) was recorded. In group E, bursting pressures and hydroxyproline levels were determined on the second postoperative day, whereas in group L, the same measurements were made on the sixth postoperative day. One-way analysis of variance was used for analyses of variance in the groups. Quantitative data were analyzed with Student's t test. P value was considered significant at less than .05.

RESULTS

There was no significant difference between bursting pressures of subgroup pairs on both postoperative days 2 and 6. Hydroxyproline levels and AT were significantly better in B subgroups.

CONCLUSION

Better healing, shorter AT, and equal strength were achieved with ethyl-2-cyanoacrylate compared with polyglactin 910 sutures in intestinal anastomosis in the experimental setting.

Efeito da suplementação dietética de arginina na cicatrização das anastomoses colônicas em ratos

RACIONAL: A arginina, aminoácido condicionalmente essencial, participa de diversos processos fisiológicos, em particular na cicatrização e na função imune. OBJETIVO: Avaliar o efeito da suplementação por via oral da arginina na cicatrização colônica em ratos. MÉTODO: Foram utilizados 47 ratos Wistar machos, adultos, com peso médio de 345,45 ± 8,35g, alocados em gaiolas coletivas em grupos cinco ou seis animais. Todos receberam água e ração ad libitum, pesados a cada dois dias e randomizados para receberem por gavagem suplementação com arginina a 10% (grupo ARG) ou solução de aminoácidos a 10% (grupo AA) de forma isovolumétrica, isocalórica e isonitrogenada (1,5 g/kg/dia) por sete dias antes do procedimento operatório e quatro após. Um terceiro grupo recebeu solução salina isotônica (grupo SSI), isovolumetricamente. Os ratos foram submetidos a duas colônicas término-terminais confeccionadas 3 cm distais à válvula ileocecal e outra 5 cm distais à primeira, em plano único com fio monofilamentar de nylon 5-0, e foram sacrificados no 5º dia de pós-operatório Neste dia, as duas anastomoses foram ressecadas, sendo uma conservada em solução salina para medidas de tração e a outra enviada à anatomia patológica, para análise do colágeno (total, maduro e imaturo), e imunoistoquímica para a pesquisa de miofibroblastos e neovascularização. Foi avaliado o peso corpóreo ao longo do experimento. A análise estatística foi realizada com os testes t de Student e de Mann-Whitney. RESULTADOS: A comparação referente ao peso nos três grupos não evidenciou diferença significativa nos pesos iniciais, mas foi observada diferença entre os finais nos grupos SSI e AA (324,7g vs. 298g, P=0,04). A tensão foi significativamente maior no grupo AA quando comparado ao grupo SSI (0,94kgf/cm² vs 0,67 kgf/cm², P=0,04), mas não em relação ao grupo ARG (0,94kgf/cm² vs 0,70 kgf/cm², P=0,09). Quanto à força máxima de tração observou-se diferença significativa entre o grupo AA e o grupo SSI (0,18kgf vs 0,13 kgf, P=0,04) mas não em relação ao grupo ARG (0,18kgf vs 0,14 kgf, P=0,08). A força de ruptura total evidenciou valor significativamente maior para o grupo AA quando comparado ao grupo ARG (0,10kgf vs 0,06 kgf, P=0,05), mas não em relação ao grupo SSI (0,10kgf vs 0,09 kgf, P=0,54). Não foi observada diferença significativa quanto à concentração dos colágenos subtipo I e III e nem do índice de maturação de colágeno nos três grupos. Não foi observada também diferença significativa em relação à contagem de vasos sanguíneos ou miofibroblastos pela imunoistoquímica entre os três grupos. CONCLUSÃO: A administração de solução contendo 20 aminoácidos se mostrou mais efetiva do que a administração isolada de arginina nas provas de tração das anastomoses colônicas.

Percutaneous endoscopic gastrostomy tube placement is safe in patients undergoing corticosteroid therapy

BACKGROUND

Percutaneous endoscopic gastrostomy tube placement is performed commonly in patients unable to eat. Corticosteroids have been shown to increase the incidence of infections in patients undergoing surgical gastrostomy. The safety of percutaneous endoscopic gastrostomy in patients receiving corticosteroids has not been demonstrated.

METHODS

A retrospective review of 746 patients undergoing percutaneous endoscopic gastrostomy at a single institution between January 2002 and June 2007 was performed. Patients receiving corticosteroid therapy either acutely or chronically were identified. Charts were reviewed for demographic information, diagnoses, comorbidities, complications, and death.

RESULTS

Seven hundred forty-six patients underwent percutaneous endoscopic gastrostomy tube placement of which only 745 charts were complete and available for review. Ninety-four patients (12.6%) were receiving steroids at the time of the procedure. Fifty-nine patients (7.9%) received steroids for two or less weeks (acute), and 35 patients (4.5%) received steroids for more than 2 weeks (chronic). The overall incidence of complications was 98/745 (13.3%). No significant difference in post-procedural complications occurred in patients not receiving steroids 83/651 (12.7%) and steroid recipients 15/94 (16.0%). There was no difference in complications between the acute steroid group 10/59 (16.9%) and the chronic steroid group 5/35 (14.3%).

CONCLUSIONS

Percutaneous endoscopic gastrostomy tube placement may be safely performed in patients receiving corticosteroids both acutely and chronically with complication rates comparable to those patients not receiving steroid medications.

Anastomotic healing in ileum and colon of alloxan-induced diabetic rats

PURPOSE: To investigate if diabetes mellitus may alter breaking strength (BS) and collagen content in ileum and colon anastomoses in rats. METHODS: Three-hundred Wistar rats were randomly assigned to 5 experimental groups, 60 per group: normal controls surgically manipulated (G1); normal controls submitted to ileum (G2) and colon (G3) anastomotic construction; diabetic rats submitted to ileum (G4) and colon (G5) anastomotic construction. Each group was further divided into 6 subgroups with 10 rats each for sacrifice at 0, 4, 7, 14, 21, and 30 days after surgery. All surgical procedures were performed 3 months after alloxan diabetes induction. BS was measured in all intestinal anastomoses. Fragments of ileum and colon anastomoses were taken for hydroxyproline concentration (HP) and total tissue protein (TP) dosages. RESULTS: Anastomotic BS was significantly decreased (P<0.05) in ileum and colon of G4 and G5 diabetic groups up to 7 and 14 days after surgery, respectively, compared with G2 and G3 normal control groups. Anastomotic HP and TP content did not significantly differ between diabetic and normal control operated groups in ileum or colon at all evaluation times. CONCLUSION: Experimental diabetes leads to impaired intestinal anastomotic strength during early surgical wound repair, but does not appear to be implicated with collagen synthesis capacity.

Mechanical bowel preparation for elective colorectal surgery

BACKGROUND

The presence of bowel contents during surgery has been related to anastomotic leakage, but the belief that mechanical bowel preparation (MBP) is an efficient agent against leakage and infectious complications is based on observational data and expert opinions only.

OBJECTIVES

To determine the security and effectiveness of MBP on morbidity and mortality in colorectal surgery.

SEARCH STRATEGY

Publications describing trials of MBP before elective colorectal surgery were sought through searches of MEDLINE, EMBASE, LILACS, and The Cochrane Library; by handsearching relevant medical journals and conference proceedings, and through personal communication with colleagues.Searches were performed March 13, 2008.

SELECTION CRITERIA

Randomised controlled trials (RCTs) including participants submitted for elective colorectal surgery. Eligible interventions included any type of MBP compared with no MBP. Primary outcomes included anastomosis leakage - both rectal and colonic - and combined figures. Secondary outcomes included mortality, peritonitis, reoperation, wound infection, extra-abdominal complications, and overall surgical site infections.

DATA COLLECTION AND ANALYSIS

Data were independently extracted and checked. The methodological quality of each trial was assessed. Details of randomisation, blinding, type of analysis, and number lost to follow up were recorded. For analysis, the Peto-Odds Ratio (OR) was used as the default (no statistical heterogeneity was observed).

MAIN RESULTS

Four new trials were included at this update (total 13 RCTs with 4777 participants; 2390 allocated to MBP (Group A), and 2387 to no preparation (Group B), before elective colorectal surgery) .Anastomotic leakage occurred:(i) in 10.0% (14/139) of Group A, compared with 6.6% (9/136) of Group B for low anterior resection; Peto OR 1.73 (95% confidence interval (CI): 0.73 to 4.10).(ii) in 2.9% (32/1226) of Group A, compared with 2.5% (31/1228) of Group B for colonic surgery; Peto OR 1.13 (95% CI: 0.69 to 1.85). Overall anastomotic leakage occurred in 4.2% (102/2398) of Group A, compared with 3.4% (82/2378) of Group B; Peto OR 1.26 (95% CI: 0.941 to 1.69). Wound infection occurred in 9.6% (232/2417) of Group A, compared with 8.3% (200/2404) of Group B; Peto OR 1.19 (95% CI: 0.98 to 1.45). Sensitivity analyses did not produce any differences in overall results.

AUTHORS' CONCLUSIONS

There is no statistically significant evidence that patients benefit from MBP. The belief that MBP is necessary before elective colorectal surgery should be reconsidered. Further research on patients submitted for elective colorectal surgery in whom bowel continuity is restored, with stratification for colonic and rectal surgery, is still warranted.

Effects of the histamine H2 receptor antagonist famotidine on the healing of colonic anastomosis in rats

BACKGROUND

Failure of anastomotic healing is one of the major complications in colorectal surgery. Because histamine plays an important role in immune and inflammatory reactions, we demonstrate the effects of famotidine on the healing of colonic anastomosis in rats.

METHODS

Twenty-eight Sprague-Dawley rats were used in the study. Excision and end-to-end anastomosis was performed in the distal colon of the rat. The Famotidine Group received 2 mg/kg/day famotidine; the Control Group received the same amount of saline. Bursting pressure of anastomoses and hydroxyproline content of perianastomotic tissues were evaluated on the third and seventh days following surgery.

RESULTS

Bursting pressures and hydroxyproline contents for the Famotidine Group were significantly lower than the equivalent parameters for the Control Group on both the third and seventh days post-surgery.

CONCLUSIONS

According to our findings, famotidine exerts detrimental effects on the anastomotic bursting pressure and hydroxyproline content of perianastomotic tissues in the colon of rats.

The effects of intraperitoneal sildenafil administration on healing of left colonic anastomoses and intra-abdominal adhesion formation in the presence of intra-abdominal infection

PURPOSE

The objective of this pilot study was to establish an animal model for intra-abdominal infection and to examine the effect of sildenafil on anastomotic healing of the left colon and intra-abdominal adhesion formation.

METHODS

Fourteen Winstar rats underwent colonic transsection and primary anastomosis after performing intra-abdominal infection. Rats were divided into two groups: Group 1 (n = 7): intra-abdominal infection, resection, and anastomoses; Group 2 (n = 7): intra-abdominal infection, resection, anastomoses, and sildenafil. Anastomotic bursting pressures, hydroxyproline levels, histopathologic grading, and abdominal adhesions were accessed on the postoperative Day 7.

RESULTS

Anastomotic healing was found to be improved in terms of a bursting pressure (P = 0.02). Histopathological examination revealed an increase in angiogenesis (P = 0.007). Moreover, intra-abdominal adhesions were significantly less in rats given sildenafil (P = 0.03).

CONCLUSION

Sildenafil may improve anastomotic healing of the left colon and diminishes peritoneal adhesion formation in the presense of abdominal infection.

Anastomotic leaks after bowel resection: what does peer review teach us about the relationship to postoperative mortality?

BACKGROUND

Anastomotic leak is a dreaded complication of intestinal surgery and has been associated with a high mortality rate. But it is uncertain exactly which patient populations are at risk of death from the leak. We sought to assess the impact of surgeon volume on leak rate and to better understand the relationship of a leak to postoperative mortality.

STUDY DESIGN

All adult patients having a small or large bowel resection with anastomosis at a university hospital from July 2003 to June 2006 were entered into a prospectively maintained quality database; data were entered by a specially trained nurse practitioner who rounded daily with housestaff. Patients with a postoperative leak based on standardized criteria were identified. Patient characteristics, surgical procedure, and operating surgeon were noted. Overall complication and leak rates by surgeon were compared using Fisher's exact test. Individual case review by a group of peers was performed for all patients with a leak who died, to determine the relationship to mortality.

RESULTS

Five hundred fifty-six patients underwent resection with anastomosis during the study period. There were 27 patients with leaks (4.9%), 6 of whom died. Leak rate for the highest-volume surgeons ranged from 1.6% to 9.9% (p <0.01), and overall complication rate varied from 30.5% to 44% (p=0.04). In four of six deaths, leaks occurred in very ill patients undergoing emergency procedures and appeared to be premorbid events. In only one patient did the leak appear to be the primary cause of death.

CONCLUSIONS

The variability in leak rate by surgeons doing similar operations suggests that many leaks may be preventable. But death after a leak is most often a surrogate for a critically ill patient and was infrequently the actual cause of death.

Activated protein C prevents deleterious effects of remote reperfusion injury caused by intestinal ischemia on wound healing in the left colonic anastomoses: an experimental study in the murine model

BACKGROUND

Activated protein C (APC) is a serine protease with anticoagulant and antiinflammatory activities. The delaying effects of remote reperfusion injury on the wound-healing process in colonic anastomoses have been previously shown. In this study, we aimed to investigate whether APC protects against deleterious systemic effects of intestinal ischemia/reperfusion (I/R) injury on colonic anastomotic wound healing process.

METHODS

Male Wistar-albino rats were randomly allocated into 4 groups, and a left colonic anastomosis was performed in all animals: (1) sham-operated group, simultaneously with left colonic anastomosis, the superior mesenteric artery and collateral branches were divided from the celiac axis, and the inferior mesenteric artery were isolated but not occluded (group 1, n = 12), (2) sham + APC group, identical to group 1 except for APC treatment (100 microg/kg, intravenously, 15 minutes before construction of the colonic anastomosis), (group 2, n = 12), (3) intestinal I/R group, 60 minutes of superior mesenteric ischemia followed by reperfusion (group 3, n = 12), and (4) APC-treated group, (100 microg/kg, intravenously, 15 minutes before reperfusion) (group 4, n = 12). All animals were sacrificed, and colonic anastomotic bursting pressures were measured in vivo on day 7. Tissue samples were obtained for analysis of hydroxyproline contents, nitrate/nitrite levels, and activities of oxidative and antioxidative enzymes. The plasma levels of proinflammatory cytokines and D-dimer were also measured.

RESULTS

Intestinal I/R led to significant decreases in colonic anastomotic bursting pressures, tissue hydroxyproline contents, and activities of antioxidative enzymes, along with increases in tissue nitrate/nitrite levels, activities of oxidative enzymes, and plasma levels of proinflammatory cytokines and D-dimer (P < .05). However, APC treatment led to significant increases in colonic anastomotic bursting pressures, tissue hydroxyproline contents, and activities of antioxidative enzymes, along with decreases in tissue nitrate/nitrite levels, activities of oxidative enzymes, and plasma levels of proinflammatory cytokines and D-dimer (P < .05).

CONCLUSION

This study clearly showed that APC treatment prevented the delaying effects of remote I/R injury on colonic anastomotic wound healing process. Further clinical studies are required to determine whether APC has a useful role in the enhancement of colonic anastomotic wound healing after particular operations in which I/R injury occurs.

The effects of hyperbaric oxygen therapy on colonic anastomosis in rats with peritonitis

The aim of this study is to investigate the healing effect of hyperbaric oxygen (HBO) on colonic anastomoses in the presence of experimentally induced peritonitis. Thirty-two rats were allocated randomly into short-term anastomosis (STA), short-term anastomosis + HBO treatment (STA+HBO), long-term anastomosis (LTA), and long-term anastomosis + HBO (LTA+HBO) treatment groups. The STA and LTA groups were administered fluid resuscitation and antibiotics for 3 and 7 days, respectively, whereas the HBO treatment groups received additional HBO therapy for 3 and 7 days, respectively. The rats were reoperated on the third and the seventh days of anostomoses for evaluation. The bursting pressures in STA+HBO and LTA+HBO therapy groups were significantly higher than those in groups with anastomoses alone (p < .001 and p < .01). HBO therapy did not affect the fibrotic index neither in STA nor in LTA groups (p > .05 for both); however, it was significantly higher in LTA+HBO group than that in STA+HBO group (p < .05). The hydroxyproline level was significantly higher in LTA group than in STA group (p < .05), yet HBO therapy did not affect the hydroxyproline levels in STA or LTA groups (p > .05 for both). It is concluded that hyperbaric oxygen treatment has positive effects on colonic anastomotic healing in case of peritonitis.

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.

Role of activated protein C on wound healing process in left colonic anastomoses in the presence of intra-abdominal sepsis induced by cecal ligation and puncture: an experimental study in the rat

BACKGROUND

Activated protein C (APC) is a serine protease with anticoagulant and anti-inflammatory activities. The delaying effects of intra-abdominal sepsis on wound healing process in colonic anastomoses have been previously demonstrated. This study was designed to investigate the role of APC on wound healing process in left colonic anastomoses in the presence of intra-abdominal sepsis.

METHODS

The left colonic anastomosis was performed in 48 rats that were divided into four groups: (1) sham-operated group, laparatomy plus cecal mobilization (n = 12); (2) sham + APC group, identical to group I except for APC treatment (n = 12); (3) CLP group, cecal ligation and puncture (n = 12); 4) CLP + APC-treated group, 100 microg/kg, 15 min before the construction of colonic anastomosis (n = 12). Anastomotic bursting pressures were measured in vivo on day 7. Tissue samples were obtained for analyses of hydroxyproline (HP) contents, myeloperoxidase (MPO) acivity, malondialdehyde (MDA), and nitrate/nitrite (NO3(-) /NO2(-)) levels. The plasma levels of tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-6, and D-dimer also were measured.

RESULTS

Intra-abdominal sepsis led to significant decreases in colonic anastomotic bursting pressures and tissue HP contents, along with increases in MPO activity, MDA and NO3(-) /NO2(-) levels, and also plasma levels of TNF-alpha, IL-6, and D-dimer (P < 0.05). However, APC treatment led to significant increases in anastomotic bursting pressures and tissue HP ontents, along with decreases in MPO activity, MDA and NO3(-) /NO2(-) levels, and also plasma levels of TNF-alpha, IL-6, and D-dimer (P < 0.05).

CONCLUSIONS

This study clearly showed that APC treatment prevented the delaying effects of intra-abdominal sepsis on colonic anastomotic wound healing process. Further clinical studies are required to determine whether APC has a useful role in the enhancement of anastomotic healing during particular surgeries in which sepsis-induced injury occurs.

Effects of Cholerella sp. microalgae extract on colonic anastomosis in rats with protein-energy malnutrition

OBJECTIVE

Algae, which are used as supplementary nutrients in various countries, are products rich in protein, vitamins and minerals. The aim of this study was to investigate the effects of algae extracts on the healing of colonic anastomosis in malnourished rats.

METHOD

Seventy-two rats were randomized to three groups. Group 1 was fed with standard diet for 15 days, before and after the colonic anastomosis. Groups 2 and 3 were fed with a malnutrition diet for 15 days prior to colonic anastomosis and then with the basic diet for 15 days there after. Group 3 also received an extract of algae derived from Cholerella sp. via oral gavage postoperatively, in addition to the basic diet. Rats were killed on the 3rd, 7th and 15th postoperative day. Blood samples were collected to evaluate prealbumin, transferring and albumin levels. Anastomotic bursting pressures (BPs), histopathology and tissue hydroxyproline levels were evaluated after killing.

RESULTS

In group 3, the prealbumin level on the 3rd postoperative day and transferrin and albumin levels on the 7th and 15th postoperative days were significantly increased compared with the other groups (P < 0.05). Tissue hydroxyproline levels and anastomotic BPs of group 3 were significantly higher than in group 2 on the 3rd, 7th and 15th postoperative days (P < 0.05). Histopathological examination of the anastomosis revealed significantly better healing patterns for group 3 than for groups 1 and 2 (P < 0.05).

CONCLUSION

Extract derived from Cholerella sp. microalgae has favourable effects on healing of experimental colon anastomoses.

Effect of mesalamine on healing in experimental colon anastomosis: a randomised experimental study

OBJECTIVE

We aimed to investigate the effect of mesalamine on healing of experimental colon anastomosis model.

MATERIAL/METHODS

Forty adult male Wistar albino rats were performed segmentary colonic resection and end-to-end anastomosis. Animals were randomly divided into four groups: group I, anastomosis group, received no treatment (GI, n=8); group II, anastomosis+oral mesalamine group (100mg/kg/day); group III, anastomosis+rectal mesalamine (2mL) group, (GIII, n=8); group IV, anastomosis+oral mesalamine+rectal mesalamine (GIV, n=8) group. A sham group (n=8) was constituted and was performed laparotomy. Bursting pressure, hydroxyproline levels and histopathological characteristics of the anastomosis were analyzed.

RESULTS

Although it was not statistically significant, there was an increase in the burst pressure of the mesalamine group. When hydroxyproline measurements were compared there were statistically significant difference between the non-treated colon and all groups. There were significant differences between GI and GIII-GIV, GII and GIV. The differences between group I and II and group II and III were not statistically significant. When we compared the median amount of the histopathological changes, we found significant difference between the anastomosis and the mesalamine groups (P<0.05). But when mesalamine groups were compared with each other we did not observe a significant difference.

CONCLUSION

Mesalamine had positive effects which were not statistically significant on bursting pressure and statistically different significant effects on hydroxyproline (HP) levels based on the way of administration and statistically significant positive effects on histopathologic anastomotic healing in experimental anastomosis model.

Anastomotic leakage, the search for a reliable biomarker. A review of the literature

BACKGROUND

Colorectal anastomotic leakage (AL) is a severe complication leading to severe infection, sepsis and sometimes death. At present the diagnosis is made clinically, usually at 6-8 days after surgery. An objective biomarker reflecting the intra-abdominal milieu surrounding the anastomosis would be a useful additional diagnostic tool to make the diagnosis of AL before its clinical presentation. This review aims to assess the current status of the search for such a biomarker in peritoneal fluid.

METHOD

A literature search was carried out, using MEDLINE, PubMed and the Cochrane library, for all publications concerning human peritoneal fluid in relation to postoperative complications in general, and, more specific, anastomotic leakage after colorectal surgery.

RESULTS

Analysis of several immune parameters, tissue repair parameters, parameters for ischaemia and microbiological composition of peritoneal fluid show that these can be determined reliably in the fluid, albeit with a large variance. Furthermore the data show that changes in concentration of these parameters precede AL and other postoperative complications by several days.

CONCLUSION

The results of the review demonstrate that it is possible to distinguish between patients with and without AL by measuring biomarkers in fluid from the peritoneal drain. Prospective studies with larger numbers of patients should, however, be performed and additional biomarkers should be studied to explore the full diagnostic potential of this approach.

The effects of local and sustained release of fibroblast growth factor on wound healing in esophageal anastomoses

BACKGROUND/PURPOSE

Postsurgical complications, such as anastomotic leaks in patients with esophageal atresia, have remained unchanged during the last 3 decades. Growth factors enhance healing in several wound-healing models. Therefore, an experimental study was used to evaluate the effects of local and sustained release of basic fibroblast growth factor (FGF) on wound healing in esophageal anastomoses.

MATERIALS AND METHODS

Twenty-four male Wistar albino rats, which were subjected to a 1-cm segmental resection of the abdominal esophagus followed by end-to-end anastomosis, were allocated into 3 groups. Group I, the control group, had no gelatin film applied to the anastomosis. In group II (gelatin film without FGF) and group III (gelatin film with FGF), anastomoses were covered with unloaded and 2.55 mug FGF-loaded gelatin films, respectively. On postoperative day 7, bursting pressures, histopathologic collagen deposition, and tissue hydroxyproline concentrations of the anastomoses were then analyzed and compared.

RESULTS

Mean bursting pressures, mean submucosal and muscular collagen deposition scores, and mean tissue hydroxyproline concentrations differed significantly between groups. Mean bursting pressures were 22.5 +/- 3.1 mm Hg in group I, 29 +/- 1.6 mm Hg in group II, and 63.2 +/- 6.8 mm Hg in group III (P < .001). Mean submucosal collagen deposition scores (group I: 0.7 +/- 0.2, group II: 0.7 +/- 0.1, group III: 1.5 +/- 0.2; P = .02) and mean muscular collagen deposition scores (group I: 0.8 +/- 0.2, group II: 0.8 +/- 0.1, group III: 1.8 +/- 0.1; P = .01) were significantly higher in FGF animals than the other in the other 2 groups. Mean tissue hydroxyproline concentrations were 2.4 +/- 0.5 microg/mg in group I, 3.9 +/- 0.4 microg/mg in group II, and 6.0 +/- 1.0 microg/mg in group III (P = .007).

CONCLUSION

Local and sustained release of FGF enhanced wound healing in esophageal anastomoses in this animal model.

Effect of propolis on healing in experimental colon anastomosis in rats

INTRODUCTION

Propolis is the generic name for the resinous substance collected by honeybees, which is known to have antioxidant, anti-inflammatory, apoptosis-inducible effects. Anastomotic dehiscence after colorectal surgery is an important cause of morbidity and mortality. We aimed to assess the effect of propolis on healing in an experimental colon anastomosis in rats.

METHODS

Forty adult male Wistar albino rats were randomly assigned into 5 treatment groups with 8 rats in each: Group I, anastomosis+no treatment; Group II, anastomosis+oral propolis (600 mg/kg/d); Group III, anastomosis+oral ethyl alcohol (1 cc/d); Group IV, anastomosis+rectal propolis (600 mg/kg/d); Group V, anastomosis+rectal ethyl alcohol (1 cc/d). The bursting pressures, hydroxiproline levels and histopathological changes in each group were measured.

RESULTS

When bursting pressures were compared between groups, we observed that they were increased in the groups treated with propolis in contrast to all other groups. Hydroxiproline levels in the propolis groups were also significantly increased in contrast to the other groups. There was also a statistically significant difference in histopathological changes between the treatment types. When propolis administration methods were compared, we did not observe a statistically significant difference.

CONCLUSION

Propolis has a significantly favourable effect on healing in experimental colon anastomosis, independent from the method of administration.

Pilot study on one-stage colonic resection without lavage in obstructed left colon in children in an emergency setting

Classically, left-sided colon obstruction is managed by a multi-staged resection and defunctioning colostomy. The purpose of this study was to examine the feasibility of single-stage resection and anastomosis without intraoperative colonic lavage for acute left-sided colonic obstruction in children. Between October 2000 and May 2006, nine consecutive patients who had a one-stage left-sided colon resection without preceding colonic lavage were evaluated. The main outcome measures were anastomotic leakage, wound infection and death. There were nine patients: six were males and three were females (M:F = 2:1). Their ages ranged from 2-10 years (mean age 6 years). The obstruction was due to irreducible colo-colic intussusceptions in two patients and colo-colic intussusceptions with colonic perforation in four patients, and colo-colic intussusceptions with gangrene in three. All the patients had resection and primary anastomosis without on-table colonic lavage. There were no anastomotic leakages or deaths. Postoperative complications included superficial wound infections in two patients and dry cough in four other patients. Three patients were lost to follow up after 3 years of follow up, but the remaining six are presently doing well. Primary anastomosis without colonic lavage is safe for resection of the left colon in children in an emergency setting.

Effects of platelet rich plasma on colonic anastomosis

PURPOSE

To investigate the effect of platelet-rich plasma (PRP) on tissue maturation and wound healing in experimental colonic anastomosis.

MATERIALS AND METHODS

Thirty Sprague Dawley rats were divided into three groups of 10 rats each. Group I (control group) was subjected to colon anastomosis only. Group II (PRP group) was subjected to colon anastomosis and topical PRP was applied. Group III (Bioglue group) was subjected to colon anastomosis and topical tissue sealant was applied (Bioglue; Cryolife, Kennesaw, GA). The rats were sacrificed on postoperative day 7, and the bursting pressure of the anastomosis and tissue hydroxyproline levels were measured; histopathological changes on the anastomosis line were also examined.

RESULTS

The bursting pressure was statistically higher in the PRP group than in the control and Bioglue groups (P < 0.05). The hydroxyproline levels were also statistically higher in the PRP group than in the control and Bioglue groups (P < 0.05). Histopathologically, there was less inflammatory cell infiltration, intensive fibroblast development, and rich collagen production in the PRP group.

CONCLUSION

PRP may be used in colon anastomosis, especially in patients with impaired wound healing, to obtain a better anastomotic strength.

[Extract of Passiflora edulis in the healing process of gastric sutures in rats: a morphological and tensiometric study]

INTRODUCTION

Many substances of vegetable origin have been used since the beginning of civilization with the purpose of improving the healing process. Among them, dry leaves extract from Passiflora edulis have been shown to have an anti-inflammatory effect in rats.

PURPOSE

To analyze the effect of dry leaves extract from Passiflora edulis in the healing of gastric sutures in rats.

METHODS

Forty male adult Wistar rats were divided into two groups of 20 rats, called Passiflora group (GP) and Control group (GC) which were divided into two groups of 10 according to moment of death, on day 3 or day 7 after the operation. All animals were submitted to a midline incision and a gastrotomy was performed on the anterior wall of the stomach followed by gastric suture with polypropylene 6.0 using four stitches on a single layer. Rats from GP were given, before closure of the abdominal wall, a solution of Passiflora edulis extract, 250 mg/kg/weight, while rats from the GC were given an isovolumetric isotonic saline solution. Macroscopic evaluation included the adhesion index proposed by Knightly. Bursting pressure was measure by an electronic device. Microscopic analysis was performed including inflammation parameters.

RESULTS

All animals presented adequate healing of the abdominal wall with no clinical signs of infections or dehiscence. The adherence index was similar in both groups both on day 3 (p=0.734) and on day 7 (p=1.000). The gastric sutures presented leak with smaller insufflation pressure on the 3rd P.O. day in both groups as compared to the 3rd P.O. day. There was no significant difference of bursting pressure among the subgroups on the 3rd P.O. day (GC3=41.1 +/- 22.1 mmHg versus GP3=59.2 +/- 20.4 mmHg; p=0.074). On the 7th P.O. day, there was an increased mean bursting pressure in both groups, but there was no statistically significant difference between the two groups (p=0.850). Histologic parameters were similar in both groups, on P.O. days 3 and day 7, except for the fibroblastic proliferation, which was greater on the 7th day in GP (p=0.002).

CONCLUSION

The intraperitoneal use of Passiflora edulis extract influences favorably the healing of gastric sutures in rats because of the increase in the fibroblastic proliferation on the 7th P.O. day.

Stable gastric pentadecapeptide BPC 157 in trials for inflammatory bowel disease (PL-10, PLD-116, PL14736, Pliva, Croatia) heals ileoileal anastomosis in the rat

PURPOSE

Gastric pentadecapeptide BPC 157 (BPC 157), which has been shown to be safe in clinical trials for inflammatory bowel disease (PL-10, PLD-116, PL14736, Pliva, Croatia), may be able to cure intestinal anastomosis dehiscence. This antiulcer peptide shows no toxicity, is limit test negative, and a lethal dose is not achieved. It is stable in human gastric juice. In comparison with other standard treatments it is more effective for ulcers and various wounds, and can be used without a carrier needed for other peptides, both locally and systemically (i.e., perorally, parenterally). We studied the effectiveness of BPC 157 for ileoileal anastomosis healing in rats.

METHODS

We assessed ileoileal anastomosis dehiscence macroscopically, histologically, and biomechanically (volume [ml] infused through a syringe-perfusion pump system (1 ml/10 s), and pressure [mmHg] to leak induction [catheter connected to a chamber and a monitor, at 10 cm proximal to anastomosis]), at 1, 2, 3, 4, 5, 6, 7, and 14 days. BPC 157 (10 microg, 10 ng, 10 pg/kg i.p. (or saline [5 ml/kg]) was first administered after surgery, while it was last given 24 h before either assessment or sacrifice.

RESULTS

Throughout the experiment, both higher doses of BPC 157 were shown to improve all parameters of anastomotic wound healing. The formation of adhesions remained slight, the blood vessels were filled with blood, and a mild intestinal passage obstruction was only temporarily observed. Anastomosis without leakage induces markedly higher volume and pressure values, with a continuous increase toward healthy values. From day 1, edema was markedly attenuated and the number of granulocytes decreased, while from days 4 or 5 necrosis decreased and granulation tissue, reticulin, and collagen formation substantially increased, thus resulting in increased epithelization.

CONCLUSION

This study showed BPC 157 to have a beneficial effect on ileoileal anastomosis healing in the rat.

Effects of a membrane-permeable radical scavenger, Tempol, on healing of colonic anastomoses in the cecal ligation and puncture model of polymicrobial sepsis in rats

BACKGROUND

Tempol (Sigma-Aldrich, Steinheim, Germany) is a stable piperidine nitroxide of low molecular weight that permeates biologic membranes and scavenges superoxide anions in vitro. In recent animal studies, the delaying effect of intraperitoneal sepsis on the healing of colonic anastomoses has been shown. In this study we aimed to investigate the effects of Tempol on the healing of colonic anastomoses in the presence of polymicrobial sepsis.

METHODS

Anastomosis of the left colon was performed on the day after cecal ligation and puncture (CLP) in 30 rats that were divided into 3 groups: sham-operated control (laparotomy and cecal mobilization, group I, n = 10), CLP (group II, n = 10), Tempol-treated group (30 mg/kg intravenously before the construction of colonic anastomosis, group III, n = 10). On postoperative day 6, all animals were killed and anastomotic bursting pressures were measured in vivo. Tissue samples were obtained for further investigation of anastomotic hydroxyproline (HP) contents, perianastomotic myeloperoxidase (MPO) activity, malondialdehyde (MDA), and glutathione (GSH) levels.

RESULTS

There was a statistically significant increase in MPO activity and MDA levels in the CLP group (group II), along with a decrease in GSH levels, anastomotic HP contents, and bursting pressure values when compared with controls (group I). However, Tempol treatment led to a statistically significant increase in anastomotic bursting pressure values, tissue HP contents, and GSH levels, along with a decrease in MPO activity and MDA levels in group III (P < .05).

CONCLUSIONS

This study showed that Tempol treatment significantly prevented the delaying effect of CLP-induced polymicrobial sepsis on anastomotic healing in the left colon. Further clinical studies are needed to clarify whether Tempol may be a useful therapeutic agent to increase the safety of the anastomosis during particular surgeries in which sepsis-induced organ injury occurs.

Perioperative Vasopressors Are Associated with an Increased Risk of Gastrointestinal Anastomotic Leakage

BACKGROUND

The purpose of this study was to investigate the effect of vasopressors on gastrointestinal (GI) anastomotic leaks. Vasopressors are commonly used in surgical patients admitted to the intensive care unit (ICU) and their effects on GI anastomotic integrity are unknown.

PATIENTS AND METHODS

Surgical patients admitted to the ICU in our tertiary university hospital following the creation of a GI anastomosis were studied by a retrospective chart analysis for anastomotic leaks and complications

RESULTS

A total of 223 patients with 259 GI anastomoses, mostly for cancer, were admitted to the ICU immediately after surgery. Twenty-two patients developed anastomotic leaks (9.9%). The two groups (leak versus no-leak) had similar demographics, surgery type and indication, type of anastomosis, co-morbidities, cancer, steroid use, blood transfusion, drains, and epidural catheters. Vasopressor use was associated with increased anastomotic leakage (p = 0.02, OR 3.25). Multiple vasopressors and prolonged exposure caused even higher leaking rates. This effect was independent of the medical status and operative morbidity (APACHE II, POSSUM). Blood pressure preceding vasopressor use was similar in both groups. Vasopressors might have been occasionally used to treat hypovolemia. Patients with leaks had higher reoperation rates (41% versus 1%, p < 0.0001) and mortality (21% versus 4%, p = 0.002).

CONCLUSIONS

Vasopressors appear to increase anastomotic leaks threefold, independent of clinical/surgical status or hypotension. Evidence-based guidelines are warranted for the optimal use of vasopressors in postoperative patients admitted to the ICU.

Strength of Esophageal Closure Techniques With and Without Tissue Reinforcement

OBJECTIVES

The purpose of this study was to investigate the effects of esophagotomy closure techniques on the esophageal bursting pressure.

MATERIALS AND METHODS

Altogether, 122 freshly dead sheep esophagi received from the local slaughterhouse were prepared for manual closure. After esophagotomy, the specimens were divided into four groups. An interrupted mucosal suture pattern (n = 30), an interrupted mucosal-submucosal suture pattern (n = 30), an interrupted mucosal-submucosal + over-over continuous muscular suture pattern (n = 32), and an interrupted mucosal-submucosal + reinforcement with a diaphragmatic part with full-thickness interrupted U suture pattern (n = 30) were used for esophagotomy closure; 4-0 silk was used in all specimens. Bursting pressures were measured with a sphygmomanometer.

RESULTS

We found a statistically significant difference among the bursting pressures of all groups (p < 0.001). The bursting pressure values gradually increased from group 1 to group 4 (47.6 +/- 22.7, 86.2 +/- 49.5, 185.4 +/- 53.5, and 226.8 +/- 62.4 mmHg, respectively). Reinforcing the esophageal suture line with tissue significantly increased the bursting pressure compared to the other groups.

CONCLUSIONS

Each layer of the esophagus significantly contributes to strengthening esophageal wall tension with primary esophageal closure, and reinforcement of the esophageal suture with tissue provides an additional significant increase in the bursting pressure of the esophagus.

The effect of erythropoietin on healing of obstructive vs nonobstructive left colonic anastomosis: an experimental study

Background

Anastomotic leakage is an important problem following primary resection in the left colon and is even more prominent when obstruction is present. We aimed to evaluate the possible effects of erythropoietin on the healing of anastomosis under both obstructive and non-obstructive states.

Methods

Forty male Wistar albino rats were divided into four groups. In group I, two cm left colonic resection and primary anastomosis were done. In group II, left colon were completely ligated and 24 hours later animals were re-operated for segmental resection. The same procedures were performed for rats in group III and IV in respect to group I and II and, 500 IU/kg a day erythropoietin were given in the latter two groups for seven days. For the quantative description of anastomotic healing mechanical, biochemical and histopathological parameters were employed on the seventh day and the animals were sacrificied.

Results

Although erythropoietin had positive effects on bursting pressure in group IV when compared to group II, it has no effect in group III. Despite the increased tissue hydroxyproline levels in group IV, erythropoietin failed to show any effects in group III.

Erythropoietin had positive effects on neovascularization, fibroblast proliferiation and storage of collagen in group IV.

Conclusion

We failed to find any direct and evident effects of erythropoietin on healing of left colonic anastomosis. On the other hand, erythropoietin might prevent negative effects of obstruction on healing.

Preparar el colon para la cirugía. ¿Necesidad real o nada más (y nada menos) que el peso de la tradición?

Mechanical bowel preparation is a traditional procedure for preparing patients for colorectal surgery. This practice aims to reduce the risk of postoperative infectious complications since colonic fecal content has classically been related to stool spillage during surgery and anastomotic disruption. However, increasing evidence against its routine use can be found in experimental studies, clinical observations, prospective studies, and meta-analyses. We performed a review of the literature on mechanical bowel preparation and its consequences. There is no clear evidence that preoperative bowel cleansing reduces the septic complications of surgery and routine use of this procedure may increase anastomotic leaks and morbidity. Therefore, the results suggest that mechanical preparation is not required in elective colon and rectal surgery and that its use should be restricted to specific indications such as small nonpalpable tumors to aid their localization during laparoscopic procedures or to enable intraoperative colonoscopy. The role of mechanical bowel preparation in rectal surgery is not well defined and further trials with a larger number of patients are required.

Early glutamine-enriched enteral feeding facilitates colonic anastomosis healing: light microscopic and immunohistochemical evaluation

Problems related to colonic anastomosis healing constitute the major morbidity in colorectal surgery. Patients without appropriate nutritional support are at higher risk of postsurgical complications, mainly due to reduced wound healing. Therefore, we investigated the effect of early and late postoperative total enteral nutrition (TEN) and glutamine addition on colon anastomosis healing using light microscopy and immunohistochemistry (IGF-I immunolabelling). In this study, 40 Wistar-albino rats underwent distal left colonic transection and anastomosis. The rats were then divided into four groups given different diets: delayed total enteral nutrition (dTEN; beginning 3 days postoperatively), delayed TEN with added glutamine (dTEN+Glutamine), early TEN (eTEN; beginning within 6h postoperatively), and early TEN with added glutamine (eTEN+Glutamine). Colon segments, including the anastomosis, were excised 7 days postoperatively and evaluated histopathologically for inflammation, mucosal healing, submucosal-muscular layer repair, the amounts of necrosis and vascularisation and immunohistochemically for IGF-I labelling. The inflammation and necrosis scores in the dTEN and dTEN+Glutamine groups were significantly greater than in the eTEN and eTEN+Glutamine groups. The IGF-I immunoreactivity increased in the eTEN, eTEN+Glutamine, and dTEN+Glutamine groups compared to dTEN (p<0.05). We concluded that early TEN and glutamine enrichment in the postoperative period improve anastomosis healing via IGF-I.

The effect of purified micronized flavonoid fraction on the healing of anastomoses in the colon in rats

PURPOSE

Anastomotic leakage of colonic and rectal anastomoses is a major complication after large intestine surgery. Many factors influence the healing of colon anastomoses. Flavonoids have been recognized for centuries as physiologically active constituents that are used to treat human diseases. We studied the effects of a clinically used, micronized, purified flavonoid fraction on the healing of colonic anastomosis in rats.

METHODS

Male Sprague-Dawley rats were used. The flavonoid group of rats received 100 mg/kg per day of Daflon for 14 days until surgery. Thereafter, a resection and anastomosis were performed. The bursting pressure of the anastomoses and the hydroxyproline levels of the perianastomotic tissue were determined to evaluate the healing on the third and seventh days of surgery for both flavonoid and control groups.

RESULTS

The bursting pressure of the flavonoid group was higher on the seventh day. The hydroxyproline levels of the flavonoid group were significantly higher than in the control group on both the third and seventh days after surgery.

CONCLUSIONS

Although the micronized purified flavonoid fraction has some inhibitory properties on the healing of the anastomosis, its net effect was to obtain a better anastomotic healing of the colon in rats.

Effect of pentoxifylline on the healing of ischemic colorectal anastomoses

PURPOSE

The aim of this study was to evaluate the effect of pentoxifylline on the healing of experimental ischemic colorectal anastomoses.

METHODS

Ninety-three Wistar rats were randomized into three groups (n = 31) and underwent resection of a colonic segment at the colorectal junction. Group A rats received standard end-to-end anastomoses. Ischemic anastomoses were performed in Groups B and C rats by coagulating mesocolon vessels 2 cm along each anastomotic end. Group C rats were treated with intraperitoneal injection of pentoxifylline. Wound complications, intra-abdominal abscesses, intraperitoneal adhesions, and anastomotic leaks and stenosis were recorded. Bursting pressure and tension were calculated. Histologic examination of the anastomosis was also performed.

RESULTS

Ischemia increased wound and intra-abdominal infections, adhesion formation, and anastomotic stenosis. Anastomotic leakage was significantly higher in Group B (45.2 percent) than in Group A (9.7 percent). Bursting pressure and tension were significantly lower in Group B (118.19 mmHg and 48.43 N/m) than in Group A (191.84 mmHg and 86.82 N/m). There was evidence for decreased perianastomotic fibrosis and neutrophils presence after induced ischemia and a strong tendency to reduced neovascularization. Pentoxifylline administration ameliorated the effects of ischemia, reducing wound and intra-abdominal infections, adhesion formation, and leaks (16.1 percent). Anastomotic strength increased (bursting pressure and tension of 205.55 mmHg and 87.68 N/m, respectively). Treated Group C had significantly higher neutrophils infiltration and fibrosis formation and a strong tendency to increased neovascularization compared with Group B.

CONCLUSIONS

Selective anastomotic devascularization induces ischemia and impairs experimental anastomotic healing, increasing leakage rate. These effects may be ameliorated by pentoxifylline administration.

Effects of pyrrolidine dithiocarbamate on healing of colonic anastomoses in the cecal ligation and puncture model of intraperitoneal sepsis in rats

INTRODUCTION

Pyrrolidine dithiocarbamate (PDTC) is a low-molecular thiol antioxidant and potent inhibitor of nuclear factor-kappaB (NF-kappaB) activation. In recent animal studies, the delaying effect of intraperitoneal sepsis on healing of colonic anastomoses has been demonstrated. In this study, we aimed to investigate the effects of PDTC on healing of colonic anastomoses in the presence of intraperitoneal sepsis induced by a rodent model of cecal ligation and puncture (CLP).

METHODS

Anastomosis of the left colon was performed on the day following CLP in 30 rats that were divided into three groups: sham-operated control (laparotomy and cecal mobilization, group I, n =10), cecal ligation and puncture (CLP) (group II, n = 10), PDTC-treated group (100 mg/kg IV before construction of the colonic anastomosis) (group III, n = 10). On postoperative day 6, all animals were sacrificed, and anastomotic bursting pressures were measured in vivo. Tissue samples were obtained for further investigation of colonic anastomotic hydroxyproline (HP) contents, perianastomotic myeloperoxidase (MPO) activity, and malondialdehyde (MDA) and glutathione (GSH) levels.

RESULTS

There was a statistically significant increase in the activity of MPO and MDA levels in the CLP group (group II) along with a decrease in GSH levels, colonic anastomotic HP contents, and bursting pressure values when compared to controls (group I). However, PDTC treatment led to a statistically significant increase in the tissue HP contents, GSH levels, and colonic anastomotic bursting pressure values, along with a decrease in MPO activity and MDA levels in group III (p < 0.05).

CONCLUSIONS

This study showed that PDTC treatment significantly prevented the delaying effect of CLP-induced intraperitoneal sepsis on anastomotic healing in the colon. Further clinical studies are needed to clarify whether PDTC may be a useful therapeutic agent to increase the safety of the anastomosis during particular operations where sepsis-induced injury occurs.

Use of intraluminal protection in colonic anastomosis in dogs

PURPOSE: To test the use of intraluminal protection in colonic anastomosis without intestinal cleansing. The intraluminal liner was fashioned from porcine submucosa preserved in glycerin and then fixed 10 cm anteriorly to the anastomotic site. This technique was compared with the one used in termino-terminal colonic anastomosis without intraluminal protection. METHODS: Twenty-eight dogs were divided into two groups of fourteen animals each. Clinical and histopathological tests were performed on the fourth and twenty-first postoperative days. RESULTS: The morbidity and mortality rates were higher in animals that did not receive the intraluminal liner. Histopathological examinations in animals in which the intraluminal liner was used showed better healing, characterized by milder inflammation and increased amount of collagen. CONCLUSION: It can be concluded that the use of intraluminal protection decreases complication rates in colonic anastomosis and promotes better healing.

Efficacy of Bioactive Polypeptides on Bleeding and Intra-Abdominal Adhesions

BACKGROUND

Perioperative bleeding and postoperative adhesions are two problems encountered in abdominal surgery. Commercial products are available that decrease both bleeding and development of abdominal adhesions, but no products are effective in both situations. The combination of differently charged bioactive polypeptides, administered intraperitoneally, has previously been shown effective in decreasing postoperative adhesions. The present study is a pilot examination of the effects on perioperative bleeding and postoperative adhesions, applying the polypeptide concept.

METHODS

Standardized wounds in the liver and spleen were induced in 52 NMRI mice. The amounts of bleeding and postoperative adhesions were measured after 1 and 7 days, respectively. Separate animals were examined after 8 weeks for long-term healing of the parenchymal wounds.

RESULTS

Both parenchymal bleeding and the extent of adhesions significantly decreased (p = 0.001 and p = 0.029, respectively) as compared to controls. Histology after 8 weeks showed no clear signs of impaired or altered healing.

CONCLUSION

Intraperitoneal administration of differently charged polypeptides significantly decreased postoperative bleeding and postoperative adhesions. Bioactive polypeptides appear promising in the promotion of peritoneal healing and merits further studies.

The effect of Bosentan on healing of colonic anastomosis

Background

Ischemia is the most important factor compromises wound healing in colonic anastomosis. Mesenteric vessels are ligated at first while performing colonic resection and following anastomosis. Therefore blood supply of the related segments of colon temporarily interrupted and ischemia can easily occur. This study was carried out to explore whether Bosentan, an endothelin-receptor antagonist, can eliminate vasoconstruction, increase blood flow in the splanchnic area and anastomotic region and therefore possibly facilitate wound healing and prevent intra-abdominal adhesion formation.

Metods

Study is conducted on 30 female Wistar-Albino rats weighing 180–240 gr. Rats were allocated into three groups. Group 1 (n = 10) recevied full-thickness resection of the left colon and end-to-end anastomosis. In Groups 2 (n = 10) and 3 (n = 10), vessels of 2–3 cm segment of the left colon were ligated, indications of necrosis of that segment were expected, followed by resection and end-to-end anastomosis. Two milliliter of saline and 5 mg/kg Bosentan was given intraperitoneally in Group 2 and 3, respectively. On postoperativ day 6, intra-abdominal adhesions were scored. Healing of anastomosis, anastomotic bursting pressures, tissue hydroxyproline levels and histopatologically healing scores were assessed.

Results

Macroscopic adhesion score in Group 3 was lower than the remained groups (p < 0.05). Tissue hydroxyproline levels were significantly higher in Group 3 compared to the Groups 1 and 2 (p < 0.001). Mean anastomotic bursting pressures were 200 mmHg, 164 mmHg and 240 mmHg in Groups 1, 2 an 3, respectively (p < 0.05 between Groups 1 and 3; p < 0.001 between Groups 2 and 3). Histopathologically, healing scores of Group 1 were significantly higher than the other groups (p < 0.05 group 1–3, group 2–3).

Conclusion

Bosentan increases anastomotic healing of ischemic colonic anastomosis and decreases intra-abdominal adhesion formation.

Preoperative and postoperative administration of hyperbaric oxygen improves biochemical and mechanical parameters on ischemic and normal colonic anastomoses

Colonic anastomotic leaks are a major postoperative complication, causing increased mortality and morbidity. Tissue ischemia is one of the most important factors that disrupt anastomotic healing. It is possible to reverse inadequate tissue oxygenation by using increased atmospheric pressure and hyperoxia, which are obtained from hyperbaric oxygen treatment (HBO). Our aim was to investigate the effects of preoperative and postoperative HBO treatment on normal and ischemic colonic anastomoses in rats. Eighty male Wistar Albino rats, weighing between 180 and 240 g, were divided into 8 equal groups. A 1-cm segment of left colon was resected 3 cm proximal to the peritoneal reflection in all groups and colonic anastomosis was performed. In groups 2, 4, 6 and 8, colonic ischemia was established by ligating 2 cm of mesocolon on either side of the anastomosis. Control groups (1 and 2) received no HBO. HBO treatment was given preoperatively in groups 3 and 4, postoperatively in groups 5 and 6, and both preoperatively and postoperatively in groups 7 and 8. HBO treatment was applied for 2 days in the preoperative period and 4 days in the postoperative period. Relaparotomy was performed on postoperative day 5 and a perianastomotic colon segment 2 cm in length was excised for detection of biochemical and mechanical parameters of anastomotic healing and histopathological evaluation. HBO treatment increased tissue hydroxyproline levels in all groups, and this difference was significant in normal anastomosis groups receiving preoperative HBO compared to controls (p = .013 for group 1 vs. group 3; p = .023 for group 1 vs. group 5). This improvement was more evident in ischemic and normal groups treated by administration of combined pre- and postoperative HBO (p = .021 and p = .013). HBO treatment also increased the mean bursting pressure values in all groups, and again, a statistically significant increase was noted in the ischemic groups compared to controls (p = .002 for group 2 vs. group 6; p = .001 for group 2 vs. group 8). Histopathological evaluation of anastomotic line fibrosis was not found to show significant differences between the groups. Adequate tissue oxygenation is the main factor in wound and anastomosis healing. HBO treatment has a positive effect on biochemical and mechanical parameters of ischemic and normal colon anastomoses in rats. It is possible to see this effect more clearly with combined HBO treatment applied before and after ischemic anastomosis.

The management of 38 anastomotic leaks after 1,684 intestinal resections

PURPOSE

This study was designed to evaluate the management of anastomotic leaks and assess the impact of outpatient leak presentation on clinical outcome.

METHODS

Thirty-eight patients with clinical anastomotic leaks from 1,684 adult patients undergoing large and small intestinal anastomosis in a tertiary referral center between January 1, 2003 and September 1, 2005 were studied. All pediatric patients and adult patients with esophageal and gastric leaks were excluded. Charts were reviewed for information on anastomotic leak management, discharge status before leak presentation, length of stay, readmissions, and mortality.

RESULTS

The overall leak rate was 2.3 percent. Eighty-seven percent of patients (n = 33) were managed operatively. Forty-two percent of patients (n = 16) were discharged after initial operation and presented as outpatients with anastomotic leak. The discharge and inpatient groups were comparable in respect to total length of stay (26.9 vs. 33.4 days) and number of readmissions (2 vs. 1.5). The overall mortality of 5 percent (n = 2) originated from the discharge group. A greater percentage of discharge patients required intensive care unit stays for more than two weeks (25 vs. 14 percent) and very long hospital admissions lasting more than two months (31 vs. 9 percent). A smaller percentage of the discharge group patients had their ostomies reversed (31 vs. 50 percent).

CONCLUSIONS

The primary management of clinical anastomotic leak remains intestinal diversion. Although length of stay was shorter in the discharge group, the number of patients who experienced significant intensive care unit stays and very long hospital stays was greater. Within the discharge group, mortality was higher and fewer patients had their ostomies reversed.

Mycophenolate Mofetil Impairs the Integrity of Colonic Anastomosis

BACKGROUND

The aim of this experimental study was to investigate the effect of mycophenolate mofetil (MMF) during the three phases of colonic anastomosis healing and specifically to check the effect of MMF on the expression of transforming growth factor-beta1 (TGF-beta1), one of the most important growth factors contributing to mechanical stability of colonic anastomosis.

MATERIALS AND METHODS

Sixty male Wistar rats underwent colonic resection and end-to-end anastomosis. The animals were divided into two groups, a study group given MMF 40 mg/kg, intraduodenally and a control group given vehicle. The rats were sacrificed at 3, 7, and 14 days (10 animals in each group). The anastomoses were tested by measuring bursting pressure and hydroxyproline content. Histological examination and immunohistochemical expression of TGF-beta1 also were assessed.

RESULTS

The mean bursting pressure in the study group was significantly lower on day 3 and 7, but there was no statistical significance on day 14. The mean hydroxyproline content was lower in the study group on days 3, 7, and 14. Histology showed decreased number of macrophages and fibroblasts on days 3 and 7 but no difference on day 14. The expression of TGF-beta1 was significantly reduced in the study group, with the difference being more pronounced on days 3 and 7.

CONCLUSION

MMF weakens the integrity of colonic anastomosis, and this effect is more significant during the inflammatory phase of healing. MMF has a negative effect on macrophages and TGF-beta1 expression, resulting in decreased collagen accumulation at the anastomosis.

Effects of unfractionated heparin and low-molecular-weight heparin on colonic anastomoses in the presence of experimental peritonitis

BACKGROUND

We aimed at investigating the effects of unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) on the healing process of colonic anastomoses in the presence of peritonitis which is known to adversely affect the healing process.

STUDY DESIGN

Three groups of Wistar albino rats (n = 15 in each group) with experimental fecal peritonitis were studied. A 1-cm colonic segment was resected, and an end-to-end anastomosis was performed. The control group (group 1) was given no treatment; group 2 animals received 50 IU/kg s.c. UFH twice a day, and group 3 rats received LMWH at a dose of 1.5 mg/kg daily for 7 days postoperatively. Relaparotomy was done on day 7 in the surviving rats. The rats were sacrificed by resection of the colonic segment. The anastomosis bursting pressures were measured and the tissue samples from anastomosis lines were histopathologically examined.

RESULTS

The bursting pressures were significantly higher in UFH and LMWH groups as compared with the controls (p = 0.021 and p < 0.001, respectively), while there was no statistically significant difference between UFH and LMWH groups. Positive bacterial culture results were more common in controls (90%) than in the other two groups (p = 0.029 and p = 0.002, respectively). Also the polymorphonuclear leukocyte counts were higher (p = 0.005) and the fibrin formation more common (p = 0.007) in the controls. On the other hand, the number of fibroblasts was higher (p = 0.002) and collagen formation and revascularization more frequent (p = 0.001 and p = 0.001, respectively) in the UFH and LMWH groups.

CONCLUSION

UFH and LMWH may have positive effects on the healing process of colonic anastomoses in the presence of peritonitis.

A concomitant review of the effects of diabetes mellitus and hypothyroidism in wound healing

This paper reviews the negative impact of diabetes mellitus or hypothyroidism on wound healing, both in experimental and clinical settings. Since both are metabolic disorders of great clinical importance, special attention is given, not only to their pathophysiology, but also to their biochemical and histological effects on tissue integrity and regeneration. Also, special focus is awarded on wound healing of the gastrointestinal tract, i.e. in intestinal anastomosis, and how these disorders can lead to wound dehiscence. Since diabetes mellitus and hypothyroidism can coexist in clinical settings, more research must be directed on their influence on wound healing, considering them as one clinical entity.

Ischemia and prolonged reperfusion before anastomotic construction do not reduce wound strength in the rat intestine

BACKGROUND

Under certain conditions, transient intestinal ischemia can reduce anastomotic strength. Preliminary findings suggest that prolonged reperfusion time, before anastomotic construction, results in reduced wound strength. The purpose of this study is to determine if wound strength indeed decreases with increasing duration of the interval between an ischemic period and construction of an anastomosis.

METHODS

In male Wistar rats, ischemia was induced by crossclamping the superior mesenteric artery (SMA) for 40 minutes. In control groups, the SMA was exposed but not clamped. Resection and anastomosis in both ileum and colon were performed immediately after release of the clamp or after 90 minutes or 24 hours. Both the anastomotic bursting pressure and breaking strength were measured after 3 or 5 days, together with hydroxyproline levels.

RESULTS

Neither bursting pressure nor breaking strength, either in ileum or in colon, changed significantly when the time between the end of ischemia and anastomotic construction increased. Similar values were obtained in all experimental and corresponding control groups. In the group in which anastomoses were constructed after 24-hour reperfusion, mechanical strength increased significantly from day 3 to day 5 and at the same rate as in the control group. No differences in anastomotic hydroxyproline levels were found between experimental and control groups analyzed at day 5.

CONCLUSIONS

A prolonged interval between intestinal ischemia and anastomotic construction does not affect development of early wound strength. Therefore, delayed anastomosis after transient ischemia is not likely to increase the risk of anastomotic complications.

Early prediction of anastomotic leak in colorectal cancer surgery by intramucosal pH

PURPOSE

Adequate oxygenation is necessary for anastomotic healing, and ischemia has been found to be one of the most important factors in anastomotic leakage. This study was designed to assess the value of early postoperative intramucosal pH measurements for the prediction of anastomotic leakage in patients with colorectal anastomosis.

METHODS

A prospective study of 90 patients with rectal or sigmoid cancer with primary anastomosis was conducted. In all patients intramucosal pH was determined by using tonometry at the anastomotic and gastric levels during the first 24 and 48 hours postoperatively. Seven other variables also were tested by univariate and multivariate analysis for any association with anastomotic leakage.

RESULTS

The rate of clinical anastomotic leakage was 6.6 percent. Multivariate analysis showed that only the intramucosal pH at the anastomosis was an independent factor for the development of anastomotic leakage. The risk of leakage was 22 times higher in patients with an anastomotic intramucosal pH < 7.28 in the first 24 hours after surgery.

CONCLUSIONS

Measurement of anastomotic intramucosal pH in the early postoperative period can more accurately predict the risk of anastomotic leakage and benefit those patients who would need additional measures to improve the viability of the anastomosis.

Effects of hyperbaric oxygen and Pgg-glucan on ischemic colon anastomosis

AIM: In colorectal surgery, anastomotic failure is still a problem in ischemia. Here, we analyzed the effects of hyperbaric oxygen and beta-glucan on colon anastomoses in ischemic condition.

METHODS: Colonic resection and anastomosis in rectosigmoid region were done in forty Wistar-Albino rats of four groups of equal number. Colon mesentery was ligated to induce ischemia. The first group was the control group. The subjects of second group were treated with hyperbaric oxygen; the third group with glucan and the forth group were treated with both. At the forth day, rats were sacrificed, anastomotic segment was resected and burst pressures and hydroxyproline levels of anastomotic line were measured.

RESULTS: The burst pressure difference of second and third groups from the control group were meaningful (P < 0.01); the forth group differed significantly from the control (P < 0.001). There was no difference between the treated groups on burst pressure level (P > 0.05). The hydroxyproline levels in all treated groups were different from the control group significantly (P < 0.001). Hydroxyproline levels in the forth group were higher than those of the second and the third groups (P < 0.001). There were no significant differences between the second and the fourth groups in burst pressure and hydroxyproline levels (P > 0.05).

CONCLUSION: Hyperbaric oxygen and glucan improve healing in ischemic colon anastomoses by anti-microbic, immune stimulating properties and seem to act synergistically when combined together.

Effect of Temporary Abdominal Closure on Colonic Anastomosis and Postoperative Adhesions in Experimental Secondary Peritonitis

BACKGROUND

The effect of relaparotomies and temporary abdominal closure on colonic anastomoses and postoperative adhesions is under debate.

METHODS

In the experiments reported here, colonic anastomosis was constructed 24 hours after cecal ligation and puncture in rats that were divided into three groups of eight animals each. The abdomen was closed primarily in groups I and II, and a Bogota bag was used for abdominal closure in group III. At 24 hours following anastomosis, relaparotomy was performed only in group II and III rats, and the abdomen was closed directly in group II; after removal of the Bogota bag in group III animals, the abdomen was closed directly. On the fifth day of anastomotic construction, bursting pressures and tissue hydroxyproline content of the anastomoses, along with peritoneal adhesions, were assessed and compared.

RESULTS

Mean anastomotic bursting pressures and hydroxyproline contents did not differ among the groups. Median adhesion scores were significantly higher in group III than the other two groups.

CONCLUSIONS

Relaparotomy and the type of temporary closure have no negative effect on anastomotic healing in rats with peritonitis. Temporary abdominal closure with a Bogota bag caused a significantly high rate of adhesions.

Effect of pantoprazole administered subcutaneously on the healing of sutured gastric incisions in rats

BACKGROUND

The properties of proton pump inhibitors most investigated are related to peptic diseases and upper gastrointestinal bleeding, but their influence on the healing of sutured gastric incisions has not been assessed. In the present study we evaluated the effect of subcutaneously administered pantoprazole on the healing of sutured gastric incisions in rats.

METHODS

Sixty rats were divided into a pantoprazole group and a control group. All rats were submitted to gastric suture in the gastric body and in the gastric fundus and had their gastric pH measured. The pantoprazole group received 20 mg/kg pantoprazole and the control group received 0.9% isotonic NaCl, both subcutaneously t.i.d. Healing analysis was carried out using collagen picrosirius red F3BA staining, and breaking strength was measured on the 4th and 7th postoperative days in all groups.

RESULTS

Gastric pH was higher in the pantoprazole group. In the fundus, the pantoprazole group had a higher measurement of breaking strength and a higher proportion of type-I over type-III collagen on the 7th postoperative day. In the body, the pantoprazole group had a higher proportion of type-I over type-III collagen on the 4th and 7th postoperative days.

CONCLUSIONS

Pantoprazole given subcutaneously promoted a reduction in gastric acid secretion and was associated with improved healing of the sutured gastric incision in the fundus (squamous epithelium) of rats. These findings suggest that pantoprazole has healing properties in sutured gastric incisions with potential benefits in gastric surgery.

Clinical review: Healing in gastrointestinal anastomoses, Part I

Gastrointestinal healing is a topic rarely reviewed in the literature, yet it is of paramount importance to the surgeon. Failure of anastomotic healing may lead to life-threatening complications, additional surgical procedures, increased length of stay, increased cost, long-term disability, and reduced quality of life for the patient. The goal of this article is to review the biological response to wounded tissue, to outline discrete differences between skin and gastrointestinal healing, to discuss local and systemic factors important to gastrointestinal healing, and to compare methods of measuring collagen content and strength of the newly formed anastomosis. Part II of this review will focus on techniques and therapies available to optimize anastomotic healing.