Influence of preoperative feeding on the healing of colonic anastomoses in malnourished rats

Mechanobiological considerations in colorectal stapling: Implications for technology development

Technological advancements in minimally invasive surgery have led to significant improvements in patient outcomes. One such technology is surgical stapling, which has evolved into a key component of many operating rooms by facilitating ease and efficacy in resection and repair of diseased or otherwise compromised tissue. Despite such advancements, adverse post-operative outcomes such as anastomotic leak remain a persistent problem in surgical stapling and its correlates (i.e., hand-sewing), most notably in low colorectal or coloanal procedures. Many factors may drive anastomotic leaks, including tissue perfusion, microbiome composition, and patient factors such as pre-existing disease. Surgical intervention induces complex acute and chronic changes to the mechanical environment of the tissue; however, roles of mechanical forces in post-operative healing remain poorly characterized. It is well known that cells sense and respond to their local mechanical environment and that dysfunction of this "mechanosensing" phenomenon contributes to a myriad of diseases. Mechanosensing has been investigated in wound healing contexts such as dermal incisional and excisional wounds and development of pressure ulcers; however, reports investigating roles of mechanical forces in adverse post-operative gastrointestinal wound healing are lacking. To understand this relationship well, it is critical to understand: 1) the intraoperative material responses of tissue to surgical intervention, and 2) the post-operative mechanobiological response of the tissue to surgically imposed forces. In this review, we summarize the state of the field in each of these contexts while highlighting areas of opportunity for discovery and innovation which can positively impact patient outcomes in minimally invasive surgery.

Early Feeding after Colorectal Surgery in Children: Is it Safe?

Aim of the Study

The aim of this study is to assess the role of early feeding after elective colorectal surgery in children and compare the outcome of feeding practice early versus traditional feeding.

Study Design

A randomized controlled, single-center study was conducted over a period of 3 years (November 2015-October 2018) at a tertiary care center.

Materials and Methods

Patients (n = 147), after colostomy closure (as elective colorectal surgery), were randomly selected for postoperative feeding initiation and were divided into two groups, namely the control (traditional feeding) group and study group (early feeding). In early group, feeding was initiated on the postoperative day 1 after the removal of nasogastric tube (removed after 16 h of surgery). Postoperative hospital stay and complications were compared among them.

Statistical Analysis Used

Data were tabulated and analyzed in Microsoft Excel 2010.

Results

Among 147 patients (boys[70] and girls [77]), the average age of colostomy closure was 4.36 years. Forty-five patients had early feeding and 102 traditional feeding. Average postoperative hospital stay was noted 5.62 ± 1.11 days for "Study group" and 8.1 ± 1.04 days for "Control group." Postoperative complications were found in 17 patients; 11 (7.5%) superficial surgical site infection (9 [8.8%] in control and 2 [4.4%] in study group) and 6 (4%) minor fecal fistulae (5 [4.9%] in control group and 1 [2.2%] in study group). None required any further surgical intervention. No mortality was reported.

Conclusions

Early feeding initiation after elective colorectal surgery is safe, and postoperative hospital stay is significantly reduced. It is definitely a step forward in the era of fast track surgery in pediatric population.

Preoperative liver shrinking diet for bariatric surgery may impact wound healing: a randomized controlled trial

BACKGROUND

In bariatric surgery, preoperative very low-calorie diets (VLCD) may better meet the technical demands of surgery by shrinking the liver. However, diets may affect tissue healing and influence bowel anastomosis in an as-yet-undefined manner.

OBJECTIVE

This randomized controlled trial aimed to examine the effect on collagen deposition in wounds in patients on a 4-week VLCD before laparoscopic gastric bypass.

SETTING

University hospital.

METHODS

The trial was undertaken in patients undergoing laparoscopic Roux-en-Y gastric bypass, with a control group (n = 10) on normal diet and an intervention group (n = 10) on VLCD (800 kcal) for 4 weeks. The primary outcome measured was expression of collagen I and III in skin wounds, with biopsies taken before and after the diet and 7 days postoperatively as a surrogate of anastomotic healing. Secondary outcome measures included liver volume and fibrosis score, body composition, operating time, blood loss, hospital stay, and complications.

RESULTS

Patients in both groups were similar in age, sex, body mass index (53.4 versus 52.8 kg/m²), co-morbidities, liver volume, and body composition. Expression of mature collagen type I was significantly decreased in diet patients compared with controls after 4 weeks of diet and 7 days after surgery. This was significant decrease in liver volume (23% versus 2%, P = .03) but no difference in operating times (129 versus 139 min, P = .16), blood loss, length of stay, or incidence of complications.

CONCLUSIONS

Preoperative diets shrink liver volume and decrease expression of mature collagen in wounds after surgery. Whether the latter has a detrimental effect on clinical outcomes requires further evaluation.

Enteral feeding with low-methoxyl pectin accelerates colonic anastomosis healing in rats

OBJECTIVE

Enteral feeding with pectin has proven beneficial for anastomosis healing in rats. The aim of this study was to investigate the effects of low-methoxyl pectin (LMP) or high-methoxyl pectin (HMP), on colonic anastomosis healing in rats.

METHODS

Male Sprague-Dawley rats (age 7 wk) were fed liquid diets containing LMP, HMP, or no pectin (pectin-free [PF]) for 14 d (n = 10/group). The rats underwent colonic anastomosis surgery on day 7 and were sacrificed on day 14. Bursting pressure, breaking strength, and salt-soluble hydroxyproline at the anastomosis site were used as indices of anastomosis healing. Short-chain fatty acids (SCFAs) in the cecal contents were analyzed.

RESULTS

Breaking strength was higher in the LMP group than in the other two groups (P < 0.001). The salt-soluble hydroxyproline content was higher in LMP group than in the PF group (P < 0.01). Bursting pressure did not differ among the three groups. The LMP group produced normal, formed stools, whereas watery stools were observed in HMP and PF groups throughout the experimental period. Cecal SCFAs were highest in LMP group.

CONCLUSIONS

These results suggest that LMP promotes healing of colonic anastomosis more effectively than HMP, which may be explained by the mechanical stresses generated by the movement of normally formed stool though the colon.

Influence of preoperative supplementation of omega-3 fatty acid in the healing of colonic anastomoses in malnourished rats receiving paclitaxel

OBJECTIVE

To evaluate the effect of preoperative supplementation of omega-3 fatty acids on the healing of colonic anastomoses in malnourished rats receiving paclitaxel.

METHODS

we studied 160 male Wistar rats, divided in two groups: one subjected to malnutrition by pair feeding (M) for four weeks, and another that received food ad libitum (W). In the fourth week, the groups were further divided into two subgroups that received omega-3 or olive oil by gavage. The animals were submitted to colonic transection and end-to-end anastomosis. After the operation, each of the four groups was divided into two subgroups that received intraperitoneal isovolumetric solutions of saline or paclitaxel.

RESULTS

mortality was 26.8% higher in the group of animals that received paclitaxel (p = 0.003). The complete rupture strength was greater in well-nourished-oil Paclitaxel group (WOP) compared with the the malnourished-oil Paclitaxel one (MOP). The collagen maturation index was higher in well-nourished-oil saline group (WOS) in relation to the malnutrition-oil-saline group (MOS), lower in malnourished-oil-saline group (MOS) in relation to malnourished-ômega3-saline one (M3S) and lower in the well-nourished-omega3-saline group (W3S) compared with the malnourished-omega3-saline (M3S). The blood vessel count was higher in the malnourished-oil-saline group (MOS) than in the malnourished-oil-paclitaxel group (MOP) and lower in the malnourished-oil-saline group (MOS) in relation to the malnourished-omega3-paclitaxel group (M3P).

CONCLUSION

supplementation with omega-3 fatty acids was associated with a significant increase in the production of mature collagen in malnourished animals, with a reversal of the harmful effects caused by malnutrition associated with the use of paclitaxel on the rupture strength, and with a stimulus to neoangiogenesis in the group receiving paclitaxel.

Nutritional Aspects of Gastrointestinal Wound Healing

Significance: Although the wound healing cascade is similar in many tissues, in the gastrointestinal tract mucosal healing is critical for processes such as inflammatory bowel disease and ulcers and healing of the mucosa, submucosa, and serosal layers is needed for surgical anastomoses and for enterocutaneous fistula. Failure of wound healing can result in complications including infection, prolonged hospitalization, critical illness, organ failure, readmission, new or worsening enterocutaneous fistula, and even death. Recent Advances: Recent advances are relevant for the role of specific micronutrients, such as vitamin D, trace elements, and the interplay between molecules with pro- and antioxidant properties. Our understanding of the role of other small molecules, genes, proteins, and macronutrients is also rapidly changing. Recent work has elucidated relationships between oxidative stress, nutritional supplementation, and glucose metabolism. Thresholds have also been established to define adequate preoperative nutritional status. Critical Issues: Further work is needed to establish standards and definitions for measuring the extent of wound healing, particularly for inflammatory bowel disease and ulcers. In addition, a mounting body of evidence has determined the need for adequate preoperative nutritional supplementation for elective surgical procedures. Future Directions: A large portion of current work is restricted to model systems in rodents. Therefore, additional clinical and translational research is needed in this area to promote gastrointestinal wound healing in humans, particularly those suffering from critical illness, patients with enterocutaneous fistula, inflammatory bowel disease, and ulcers, and those undergoing surgical procedures.

Preoperative vitamin C supplementation improves colorectal anastomotic healing and biochemical parameters in malnourished rats

PURPOSES

The objective of this study was to evaluate the effect of supplementation with vitamin C on intestinal anastomosis healing in malnourished rats.

METHODS

Male Wistar rats were divided into three groups: (1) sham, well-nourished rats that received vehicle; (2) FR+Veh, rats that were subjected to food restriction and received vehicle; and (3) FR+VC, rats that were subjected to food restriction and received vitamin C. Four days before surgery, the animals received vitamin C (100 mg/kg/day) via gavage and underwent colon resection with anastomosis in a single plane. The survival rate of rats was monitored until day 7 after surgery. Regarding anastomosis tissues, we examined intra-abdominal adhesion index, hydroxyproline content, collagen density, inflammatory parameters, and oxidative damage to proteins and lipids.

RESULTS

Malnutrition decreases body weight and increases mortality; the survival rate was 90 % in group 1, 60 % in group 2, and 80 % in group 3. Vitamin C was able to increase hydroxyproline concentration and density of collagen and decrease the intra-abdominal adhesion index, as well as the infiltration of neutrophils and oxidative damage to proteins in malnourished rats compared to group treated with vehicle.

CONCLUSIONS

Preoperative vitamin C supplementation can improve the intestinal anastomosis healing, biochemical alterations, and prolong survival in rats subjected to food restriction.

Effects of preoperative nutritional support on colonic anastomotic healing in malnourished rats

OBJECTIVE

It has been proven that malnutrition increases postoperative morbidity and mortality, and it may also negatively affect wound healing in the gastrointestinal tract. In the literature, there is only one study evaluating the effects of preoperative nutritional support on colonic anastomotic healing under malnourished conditions. In order to improve the data on this topic, an experimental study was planned to evaluate the effects of preoperative nutritional support on colonic anastomotic healing in malnourished rats.

MATERIAL AND METHODS

The study included 18 male Wistar albino rats divided into 3 groups. The control (C) group was fed ad libitum for 21 days. The malnutrition (M) group and preoperative nutrition (P) group were given 50% of the daily food consumed by the rats in Group C for 21 days to induce malnutrition. At the end of 21 days, Group P was fed ad libitum for 7 days (preoperative nutritional support). Colonic transection and end-to-end anastomosis was performed at 21 days in Group C and Group M and at 28 days in Group P. The rats were sacrificed at postoperative 4 days, anastomotic bursting pressure was measured, and samples were taken to analyze tissue hydroxyproline levels.

RESULTS

Anastomotic bursting pressure was significantly higher in Group C than in Group M and Group P (p<0.05), and it was significantly higher in Group P than in Group M (p<0.05). Tissue hydroxyproline levels in Group P were found to be significantly higher than those in Group M and Group C (p<0.05).

CONCLUSION

One week of preoperative nutritional support increases collagen synthesis in the colon and positively affects anastomotic healing under malnourished conditions.

A randomized controlled trial evaluating early versus traditional oral feeding after colorectal surgery

OBJECTIVE

This prospective randomized clinical study was conducted to evaluate the safety and tolerability of early oral feeding after colorectal operations.

METHODS

A total of 199 patients underwent colorectal surgery and were randomly assigned to early feeding (n = 99) or a regular diet (n = 100). Patients' characteristics, diagnoses, surgical procedures, comorbidity, bowel movements, defecation, nasogastric tube reinsertion, time of tolerance of solid diet, complications, and length of hospitalization were assessed.

RESULTS

The two groups were similar in terms of gender, age, diagnosis, surgical procedures, and comorbidity. In the early feeding group, 85.9% of patients tolerated the early feeding schedule. Bowel movements (1.7±0.89 vs. 3.27±1.3), defecation (3.4±0.77 vs. 4.38±1.18) and time of tolerance of solid diet (2.48±0.85 vs. 4.77±1.81) were significantly earlier in the early feeding group. There was no change between the groups in terms of nasogastric tube reinsertion, overall complication or anastomotic leakage. Hospitalization (5.55±2.35 vs. 9.0±6.5) was shorter in the early feeding group.

CONCLUSIONS

The present study indicated that early oral feeding after elective colorectal surgery was not only well tolerated by patients but also affected the postoperative outcomes positively. Early postoperative feeding is safe and leads to the early recovery of gastrointestinal functions.

Intraoperative laser fluorescence angiography in colorectal surgery: a noninvasive analysis to reduce the rate of anastomotic leakage

PURPOSE

Up to 19% of all colorectal resections develop clinically apparent insufficiencies. Insufficient perfusion of the anastomosis is recognized as an important risk factor. As tissue perfusion can be objectified intraoperatively using laser fluorescence angiography (LFA), its effect on the rate of anastomotic complications was evaluated in a retrospective matched-pairs analysis.

METHODS

Between 2003 and 2008, all anastomosis or resection margins in colorectal cancer resections were investigated intraoperatively using LFA (LFA group). Patients with colorectal cancer resections between 1998 and 2003 without LFA served as the control group. Four hundred two patients were matched for age, T-stage, type of resection and anastomosis, defunctioning stoma, administration of blood, emergency conditions, and body mass index. Statistical analysis was performed using the Fisher and the Wilcoxon tests.

RESULTS

Twenty-two surgical revisions were necessary due to anastomotic leakage, seven (3.5%) in the LFA group and 15 (7.5%) in the control group. Subgroup analysis revealed that in elective resections the rate of revision was 3.1% (LFA group) and 7.7% (control group) (p = 0.04, risk of revision (ROR) reduced by 60%). In patients older than 70 years, the rate of revision was 4.3% (LFA group) compared to 11.9% (control group) (p = 0.04, ROR reduced by 64%). After hand-sewn anastomosis, the rate of revision was 1.2% (LFA group) and 8.5% (control group) (p = 0.03, ROR reduced by 84%). Hospital stay was significantly reduced in the LFA group (Wilcoxon test; p = 0.01).

CONCLUSION

There was an overall reduction in the absolute revision rate of 4% in the LFA group and a significantly reduced rate of revision in the subgroup analysis of patients undergoing elective colorectal resections, in patients older than 70 years and in patients with hand-sewn anastomosis. This demonstrates that LFA is a method that may significantly reduce not only the rate of severe complications in colorectal surgery but also the hospital length of stay.

Nutrition management of pressure ulcers

Despite our knowledge of how to prevent pressure ulcers, and improvements in treatment, pressure ulcers remain prevalent and impose a significant burden on financial and labor resources in the healthcare industry. Although there is no known role for specific nutrients in the prevention of pressure ulcers, undernutrition is a risk factor, and nutrition therapy plays a crucial role in pressure ulcer treatment. Limitations in research make it difficult to develop evidence-based nutrition guidelines, so it is important that clinicians conduct a comprehensive assessment that includes weight and intake history, biochemical data, and comorbidities as well as symptoms that may affect the intake, absorption, or excretion of nutrients. These data, combined with clinical judgment, must be used to estimate energy and protein needs, considering the size and severity of the pressure ulcer. Micronutriture is difficult to assess; usual intake, comorbidities and disease symptoms must be considered in addition to biochemical data. Micronutrients should be replaced if depleted, but routine supplementation of vitamins and minerals in all pressure ulcer patients is not warranted.