Stimulation of the autonomic nervous system in colorectal surgery: a study protocol for a randomized controlled trial

Transcutaneous Auricular Vagal Nerve Stimulation in Healthy Non-Sedated Horses: A Feasibility Study

This study aimed to evaluate the feasibility of transcutaneous auricular vagal nerve stimulation (tAVNS) in healthy horses and its effect on heart rate variability (HRV). The study comprised three phases: the selection of mares, their acclimatization to the tAVNS, and the stimulation phase. Stimulation was performed with two electrodes positioned on the right pinna. The settings were 0.5 mA, 250 μs, and 25 Hz for pulse amplitude, pulse width, and pulse frequency, respectively. HRV was analysed before (B1), during (T), and after (B2) the tAVNS. From the 44 mares initially included, only 7 completed the three phases. In these mares, the heart rate (HR) was significantly lower, and frequency domain parameters showed an increased parasympathetic tone in B2 compared with B1. However, in 3/7 mares, the HR was significantly higher during T compared with B1 and B2, compatible with a decreased parasympathetic tone, while in 4/7 mares, the HR was significantly lower and the parasympathetic nervous system index was significantly higher during T and B2 compared with B1. The tAVNS is an economical and easy procedure to perform and has the potential to stimulate vagal activity; however, it was poorly tolerated in the mares included in this study.

Efficacy of Celiac Branch Preservation in Billroth-Ⅰ Reconstruction After Laparoscopy-Assisted Distal Gastrectomy

BACKGROUND

The goal of the present retrospective study was to elucidate the efficacy of conserving the celiac branch (CB), which can reduce the adverse reactions of Billroth-Ⅰ (B-Ⅰ) restoration after the laparoscopy-assisted distal gastrectomy (LADG).

METHODS

Two hundred thirty-three patients with gastric cancer underwent B-Ⅰ reconstruction after LADG with dissection 2 lymphadenectomy from July 2005 to July 2012 and were monitored for 5 y. The patients were separated into 2 groups: celiac branch preserved (P-CB) group (n = 98) and celiac branch resected (R-CB) group (n = 135). In addition to patient information, tumor features, and surgical details, short-term and long-term variables such as bowel condition, surgical complications, and endoscopy findings were evaluated.

RESULTS

In short-term efficacy, the time of first flatus and liquid ingestion were slightly shorter in the P-CB group than in the R-CB group (3.84 ± 0.74 versus 4.38 ± 0.71, P = 0.0001; 5.04 ± 1.07 versus 5.67 ± 1.10, P = 0.0001). For long-term efficacy, the incidences of chronic diarrhea, gastroparesis, residual food, bile reflux, and reflux esophagitis were less in the P-CB group compare with the R-CB group (6.1% versus 22.2%, P = 0.001; 5.1% versus 17.8%, P = 0.004; 4.1% versus 17.8%, P = 0.004; 8.2% versus 17.8%, P = 0.036; 8.2% versus 17.8%, P = 0.036). Other parameters such as postoperative ileus and gallstones had a better efficacy trend in the P-CB group but did not suggestively vary among the groups.

CONCLUSIONS

The CB has an imperative part in the gastrointestinal motility, and celiac preservation mainly exerts long-term efficacy in patients who underwent B-I surgery with LADG.

Neuronal regulation of intestinal immune functions in health and disease

BACKGROUND

Nerve-mucosa interactions control various elements of gastrointestinal functions, including mucosal host defense, gut barrier function, and epithelial cell growth and differentiation. In both intestinal and extra-intestinal diseases, alterations of autonomic nerve activity have been observed to be concurrent with the disease course, such as in inflammatory and functional bowel diseases, and neurodegenerative diseases. This is relevant as the extrinsic autonomic nervous system is increasingly recognized to modulate gut inflammatory responses. The molecular and cellular mechanisms through which the extrinsic and intrinsic nerve pathways may regulate digestive mucosal functions have been investigated in several pre-clinical and clinical studies.

PURPOSE

The present review focuses on the involvement of neural pathways in gastrointestinal disease, and addresses the current strategies to intervene with neuronal pathway as a means of treatment.

Nutritional interventions to improve recovery from postoperative ileus

PURPOSE OF REVIEW

Postoperative ileus (POI) is an important contributor to postoperative morbidity. However, postoperative outcomes have improved by enhanced recovery after surgery (ERAS) programs. Enteral nutrition is an essential part of ERAS and many studies suggest a therapeutic effect of nutrition on POI.

RECENT FINDINGS

Early postoperative enteral nutrition has been shown to reduce various complications, including POI, although studies are heterogeneous. Experimental studies suggest that composition and timing of the enteral feed is important for the potential beneficial effects: lipid-enriched nutrition given just before, during, and directly after surgery was most effective in reducing POI in an experimental setting. In a clinical study in patients undergoing advanced rectal cancer surgery, direct start of enteral tube feeding reduced POI. Conversely, perioperative lipid-enriched enteral nutrition did not reduce POI in patients undergoing colorectal surgery with an ERAS protocol.

SUMMARY

POI is common and remains an important determinant of postoperative recovery following colorectal surgery. Nutrition is a potential therapeutic means to reduce POI. Timing and composition of the enteral feed have been shown to be essential for the beneficial effects of enteral nutrition in an experimental setup. However perioperative lipid-enriched nutrition does not reduce POI in patients undergoing colorectal surgery with an ERAS protocol.

The Effect of Myopenia on the Inflammatory Response Early after Colorectal Surgery

BACKGROUND

Myopenia (low skeletal muscle mass) is associated with an increased risk of complications following colorectal surgery, however, the underlying mechanism is poorly understood. This study investigates the effect of myopenia on the early postoperative systemic inflammatory response.

MATERIALS AND METHODS

In 78 patients undergoing colorectal surgery, the presence of myopenia was preoperatively assessed using computed tomography images of the third lumbar vertebra. Interleukin-8 (IL-8) and soluble tumor necrosis factor receptor-1 (TNFRSF1A) were measured in plasma before and 4 h after start of surgery as part of a randomized controlled trial investigating the effect of perioperative gum chewing on the inflammatory response. Multivariable linear regression analysis was performed to assess the effect of myopenia on inflammatory markers while correcting for possible confounders.

RESULTS

Four hours after start of surgery, IL-8 was higher in patients with myopenia than in patients without myopenia (352 ± 268 vs. 239 ± 211 pg/ml, P = 0.048), while TNFRSF1A was similar between groups. After adjusting for sex and the intervention with perioperative gum chewing, myopenia remained associated with higher postoperative IL-8 concentrations (P = 0.047).

CONCLUSION

Myopenia may affect IL-8 early after colorectal surgery. However, more studies are needed to validate these findings.

Relation between postoperative ileus and anastomotic leakage after colorectal resection: a post hoc analysis of a prospective randomized controlled trial

AIM

Anastomotic leakage (AL) following abdominal surgery is a critical determinant of postoperative recovery, of which the aetiology is largely unknown. Interestingly, interventions aimed at reducing the inflammatory response and postoperative ileus (POI) have an unexpected effect on AL. The aim of this study was to investigate the relation of POI with inflammation and AL after colorectal resection.

METHOD

A post hoc analysis of a prospective randomized controlled trial in which patients underwent a colorectal resection was performed. Patients undergoing a colorectal resection were stratified into having or not having POI. The incidence of AL and other clinical parameters was registered prospectively. Intestinal fatty acid binding protein (I-FABP, a marker for tissue damage) and the inflammatory response in plasma and colon tissue were determined.

RESULTS

AL was present in nine of 43 patients in the POI group, and in one of 65 in the group without POI (P < 0.001). There was a significant association between POI and AL (OR 12.57, 95% CI: 2.73-120.65; P = 0.0005). Patients with POI had significantly higher plasma levels of soluble tumour necrosis factor receptor 1 (TNFRSF1A) at 4 h postoperatively (0.89 ng/l, interquartile range 0.56) than patients without POI (0.80 ng/l, interquartile range 0.37; P = 0.04) and higher plasma levels of C-reactive protein on the second day postoperatively (234 ± 77 vs 163 ± 86 mg/l; P = 0.001). Patients who developed AL had significantly higher plasma levels of I-FABP compared with patients without AL at 24 h after onset of surgery.

CONCLUSION

POI is associated with a higher prevalence of AL and an increased inflammatory response.

Postoperative ileus: Pathophysiology, incidence, and prevention

Postoperative ileus (POI) is a major focus of concern for surgeons because it increases duration of hospitalization, cost of care, and postoperative morbidity. The definition of POI is relatively consensual albeit with a variable definition of interval to resolution ranging from 2 to 7 days for different authors. This variation, however, leads to non-reproducibility of studies and difficulties in interpreting the results. Certain risk factors for POI, such as male gender, advanced age and major blood loss, have been repeatedly described in the literature. Understanding of the pathophysiology of POI has helped combat and prevent its occurrence. But despite preventive and therapeutic efforts arising from such knowledge, 10 to 30% of patients still develop POI after abdominal surgery. In France, pharmacological prevention is limited by the unavailability of effective drugs. Perioperative nutrition is very important, as well as limitation of preoperative fasting to 6 hours for solid food and 2 hours for liquids, and virtually no fasting in the postoperative period. Coffee and chewing gum also play a preventive role for POI. The advent of laparoscopy has led to a significant improvement in the recovery of gastrointestinal function. Enhanced recovery programs, grouping together all measures for prevention or cure of POI by addressing the mechanisms of POI, has reduced the duration of hospitalization, morbidity and interval to resumption of transit.

Effect of gum chewing on reducing postoperative ileus and recovery after colorectal surgery: A randomised controlled trial

AIM

This study aimed to determine the effect of gum chewing on the reduction of postoperative ileus and recovery after surgery.

METHODS

This study was conducted a randomized controlled trial in 60 patients who underwent colorectal surgery between November 2011 and December 2012. Patients in the experimental group chewed gum three times a day. The time of flatus and defecation, the time to start feeding, pain levels and time of discharge were monitored.

RESULTS

Post-surgery results for gum-chewing were first flatus and defecation times and the time to start feeding was shorter; pain levels were lower on the 3rd - 5th days; patients were discharged in a shorter time post-surgery.

CONCLUSIONS

Chewing gum is a simple intervention for reducing postoperative ileus after colorectal surgery. Further studies that examine the effectiveness of gum chewing on other surgical interventions in which the development risk of postoperative ileus should be performed.

Randomized clinical trial of the effect of gum chewing on postoperative ileus and inflammation in colorectal surgery

BACKGROUND

Postoperative ileus (POI) is a common complication following colorectal surgery that delays recovery and increases length of hospital stay. Gum chewing may reduce POI and therefore enhance recovery after surgery. The aim of the study was to evaluate the effect of gum chewing on POI, length of hospital stay and inflammatory parameters.

METHODS

Patients undergoing elective colorectal surgery in one of two centres were randomized to either chewing gum or a dermal patch (control). Chewing gum was started before surgery and stopped when oral intake was resumed. Primary endpoints were POI and length of stay. Secondary endpoints were systemic and local inflammation, and surgical complications. Gastric emptying was measured by ultrasonography. Soluble tumour necrosis factor receptor 1 (TNFRSF1A) and interleukin (IL) 8 levels were measured by enzyme-linked immunosorbent assay.

RESULTS

Between May 2009 and September 2012, 120 patients were randomized to chewing gum (58) or dermal patch (control group; 62). Mean(s.d.) length of hospital stay was shorter in the chewing gum group than in controls, but this difference was not significant: 9·5(4·9) versus 14·0(14·5) days respectively. Some 14 (27 per cent) of 52 analysed patients allocated to chewing gum developed POI compared with 29 (48 per cent) of 60 patients in the control group (P = 0·020). More patients in the chewing gum group first defaecated within 4 days of surgery (85 versus 57 per cent; P = 0·006) and passed first flatus within 48 h (65 versus 50 per cent; P = 0·044). The decrease in antral area measured by ultrasonography following a standard meal was significantly greater among patients who chewed gum: median 25 (range -36 to 54) per cent compared with 10 (range -152 to 54) per cent in controls (P = 0·004). Levels of IL-8 (133 versus 288 pg/ml; P = 0·045) and TNFRSF1A (0·74 versus 0·92 ng/ml; P = 0·043) were lower among patients in the chewing gum group. Fewer patients in this group developed a grade IIIb complication (2 of 58 versus 10 of 62; P = 0·031).

CONCLUSION

Gum chewing is a safe and simple treatment to reduce POI, and is associated with a reduction in systemic inflammatory markers and complications.

REGISTRATION NUMBER

NTR2867 (http://www.trialregister.nl).

Facilitating return of bowel function after colorectal surgery: alvimopan and gum chewing

Postoperative ileus is common after colorectal surgery, and has a huge impact on hospital LOS. With the impeding cost crisis in the United States, safely reducing length of stay is essential. Chewing gum and pharmacological treatment with alvimopan are safe, simple tools to reduce postoperative ileus and its associated costs. Future research will determine if integrating these tools with laparoscopic procedures and enhanced recovery pathways is a best practice in colorectal surgery.