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

Revisited Hyperoxia Pathophysiology in the Perioperative Setting: A Narrative Review

The widespread use of high-dose oxygen, to avoid perioperative hypoxemia along with WHO-recommended intraoperative hyperoxia to reduce surgical site infections, is an established clinical practice. However, growing pathophysiological evidence has demonstrated that hyperoxia exerts deleterious effects on many organs, mainly mediated by reactive oxygen species. The purpose of this narrative review was to present the pathophysiology of perioperative hyperoxia on surgical wound healing, on systemic macro and microcirculation, on the lungs, heart, brain, kidneys, gut, coagulation, and infections. We reported here that a high systemic oxygen supply could induce oxidative stress with inflammation, vasoconstriction, impaired microcirculation, activation of hemostasis, acute and chronic lung injury, coronary blood flow disturbances, cerebral ischemia, surgical anastomosis impairment, gut dysbiosis, and altered antibiotics susceptibility. Clinical studies have provided rather conflicting results on the definitions and outcomes of hyperoxic patients, often not speculating on the biological basis of their results, while this review highlighted what happens when supranormal PaO₂ values are reached in the surgical setting. Based on the assumptions analyzed in this study, we may suggest that the maintenance of PaO₂ within physiological ranges, avoiding unnecessary oxygen administration, may be the basis for good clinical practice.

Effect of preconditioning and postoperative hyperbaric oxygen therapy on colonic anastomosis healing with and without ischemia in rats

Purpose

To investigate the effect of hyperbaric oxygen therapy on colonic anastomosis healing with and without ischemia in rats.

Methods

Forty female rats underwent segmental resection of 1 cm of the left colon followed by end-to-end anastomosis. They were randomly assigned to four groups (n=10 each), a sham group; two groups were submitted to Hyperbaric Oxygen therapy (HBOT) with and without induced ischemia and the induced ischemia group without HBOT. The HBOT protocol evaluated was 100% O2 at 2.4 Atmosphere absolute pressure (ATA) for 60 minutes, two sessions before as a preconditioning protocol and three sessions after the operation. Clinical course and mortality were monitored during all experiment and on the day of euthanasia on the fourth day after laparotomy. Macroscopic appearance of the abdominal cavity were assessed and samples for breaking strength of the anastomosis and histopathological parameters were collected.

Results

There was no statistically significant difference in mortality or anastomosis leak between the four experimental groups. Anastomosis breaking strength was similar across groups.

Conclusion

The HBOT protocol tested herein at 2.4 ATA did not affect histopathological and biomechanical parameters of colonic anastomotic healing, neither the clinical outcomes death and anastomosis leak on the fourth day after laparotomy.

Systematic Review on the Influence of Tissue Oxygenation on Gut Microbiota and Anastomotic Healing

BACKGROUND

Anastomotic leak rates have not improved over several decades despite improvements in surgical techniques and patient care. The gut microbiome has been implicated in the development of leaks. The exact mechanisms by which tissue oxygenation affects gut microbial composition and anastomotic healing physiology are unclear. Also, commonly used carbon dioxide (CO₂) is a known vasodilator that improves tissue oxygen tension. We performed a systematic review to determine the influence of hyperoxia, hypoxia, and hypercapnia on the gut microbiome and anastomotic healing.

METHODS

A literature search was performed in MEDLINE, EMBASE, and COCHRANE to identify studies investigating the effects of hyperoxia, hypoxia, and hypercapnia on anastomotic healing and gut microbiota published between 1998 and 2018. Two reviewers screened the articles for eligibility and quality. Fifty-three articles underwent full text review, and a narrative synthesis was undertaken.

RESULTS

Hyperoxia is associated with better anastomotic healing, increased gastrointestinal oxygen tension, and may reduce gut anaerobes. Hypoxia is associated with poor healing and increased gut anaerobes. However, it is unclear if hypoxia is the most important predictor of anastomotic leaks. Low pressure CO₂ pneumoperitoneum and mild systemic hypercapnia are both associated with increased gastrointestinal oxygen tension and may improve anastomotic healing. We found no studies which investigated the effect of hypercapnia on gut microbiota in the context of anastomotic healing.

CONCLUSIONS

Tissue oxygenation influences gut anastomotic healing, but little evidence exists to demonstrate the influence on the gut microbiome in the context of healing. Further studies are needed to determine if anastomotic microbiome changes with altered tissue oxygenation and if this affects healing and leak rates. If confirmed, altering tissue oxygenation through hyperoxia or hypercapnia could be feasible means of altering the microbiome such that anastomotic leak rates reduce.

Assessment of Anastomotic Perfusion in Left-Sided Robotic Assisted Colorectal Resection by Indocyanine Green Fluorescence Angiography

Background

Indocyanine green fluorescent angiography (IcGA) has been used with success in guiding intraoperative management to prevent colorectal anastomotic complications. Prior studies in open and laparoscopic colorectal surgery, such as PILLAR II, have demonstrated a low anastomotic leak rate (1.4%). As the minimally invasive approach progresses from laparoscopic to robotic approach, the effect and safety of IcGA in assessing anastomotic perfusion in the latter deserve further investigation.

Methods

The objective of the study was to determine the safety of IcGA in guiding intraoperative management of robotic assisted colorectal resection via perfusion assessment. The design was single-surgeon, retrospective case-control study. 74 patients underwent left-sided robotic assisted colorectal resection and anastomosis with IcGA guidance. 30 historical controls underwent left-sided robotic assisted colorectal resection and anastomosis without IcGA. Clinical, demographic, operative, and outcome variables were tabulated.

Results

In the control group, 1 patient suffered a postoperative anastomotic stricture requiring no surgery, and 1 patient suffered an anastomotic dehiscence requiring return to the operating room. There were no anastomotic complications in the IcGA group, including 4 patients who underwent a change in the chosen level of anastomosis based on intraoperative IcGA.

Conclusion

IcGA is safe to use as demonstrated by the very low rate of complications in this case series. It is also safe to rely on to guide re-resection and recreation of an anastomosis intraoperatively by demonstration of blood flow. This may help offset the loss of tactile feedback and assessment of tension in the robotic platform.

Meta-analysis on the effect of hyperbaric oxygen as adjunctive therapy in the outcome of anastomotic healing of experimental colorectal resections in rats

BACKGROUND

Colorectal cancer is the third most common form of cancer and colorectal surgery is the treatment of choice in local disease. Anastomotic leakage following colorectal surgery is a major complication with a high incidence and mortality. Adjuvant hyperbaric oxygen treatment (HBOT) may be associated with reduction of anastomotic leakage. A systematic review was conducted regarding HBOT as an adjunctive therapy to colorectal surgery.

METHODS

Systematic review (1900-2017) using PubMed, Cochrane, EMBASE, Web of Science and EMCARE. All original published studies on the effect of HBOT as an adjunctive therapy for colorectal surgery with the creation of an anastomosis were considered.

RESULTS

Thirteen small animal trials were included for qualitative synthesis. We found no human trials. Eleven trials used bursting pressure whilst eight used hydroxyproline levels as a marker for collagen synthesis as primary outcome to assess the strength of the anastomosis. A meta-analysis performed for normal and ischaemic anastomoses showed that postoperative HBOT improves bursting pressure and hydroxyproline levels significantly in both normal (p ≤ 0.001 and p = 0.02) and ischaemic anastomoses (p ≤ 0.001 and p = 0.04).

CONCLUSION

Postoperative HBOT has a positive effect on colorectal anastomoses in rats. Further research should focus on a larger systematic animal study.

Therapeutic improvement of colonic anastomotic healing under complicated conditions: A systematic review

AIM: To identify therapeutic agents for the prophylaxis of gastrointestinal anastomotic leakage (AL) under complicated conditions.

METHODS: The PubMed and EMBASE databases were searched for English articles published between January 1975 and September 2014. Studies with the primary purpose of improving anastomotic healing in the colon or rectum under complicated preoperative and/or intraoperative conditions were included. We excluded studies investigating the adverse effects or risk assessment of an active intervention. Furthermore, investigations of biophysical materials, sealants, electrical stimulation and nutrients were excluded. The primary study outcome was biomechanical anastomotic strength or AL. The meta-analysis focused on therapeutic agents that were investigated in one animal model using the same outcome by at least three independent research groups.

RESULTS: The 65 studies included were divided into 7 different complicated animal models: Bowel ischemia, ischemia/reperfusion, bowel obstruction, obstructive jaundice, peritonitis, chemotherapy and radiotherapy. In total, 48 different therapeutic compounds were examined. The majority of investigated agents (65%) were reported as beneficial for anastomotic healing. Twelve of the agents (25%) were tested more than once in the same model, whereas 13 (27%) of the agents were tested in two or more models of complicated healing. Two therapeutic agents met our inclusion criteria for the meta-analysis. Postoperative hyperbaric oxygen therapy significantly increased anastomotic bursting pressure in ischemic colon anastomoses by a mean of 28 mmHg (95%CI: 17 to 39 mmHg, P < 0.00001). Granulocyte macrophage-colony stimulating factor failed to show a significant increase in anastomotic bursting pressure (95%CI: -20 to 21 mmHg, P = 0.97) vs controls in experimental chemotherapeutic models.

CONCLUSION: This systematic review identified potential therapeutic agents, but more studies are needed before concluding that any of these are useful for AL prophylaxis.

Hyperbaric oxygen therapy improves colorectal anastomotic healing

PURPOSE

Hyperbaric oxygen treatment (HBOT) has been found to improve the healing of poorly oxygenated tissues. This study aimed to investigate the influence of HBOT on the healing in ischemic colorectal anastomosis.

METHODS

Forty Wistar rats were randomly divided into a treatment group that received HBOT for 10 consecutive days (7 days before and 3 days after surgery), or in a control group, which did not receive the therapy. Colectomy with an ischemic anastomosis was performed in all rats. In each group, the rats were followed for 3 or 7 days after surgery to determine the influence of HBOT on anastomotic healing.

RESULTS

Five rats from each group died during follow-up. No anastomotic dehiscence was seen in the HBOT group, compared to 37.5 % and 28.6 % dehiscence in the control group on postoperative day (POD) 3 and 7, respectively. The HBOT group had a significantly higher bursting pressure (130.9 ± 17.0 mmHg) than the control group (88.4 ± 46.7 mmHg; p = 0.03) on POD 3. On POD 3 and POD 7, the adhesion severity was significantly higher in the control groups than in the HBOT groups (p < 0.005). Kidney function (creatinine level) of the HBOT group was significantly better than of the control group on POD 7 (p = 0.001). Interestingly, a significantly higher number of CD206+ cells (marker for type 2 macrophages) was observed in the HBOT group at the anastomotic area on POD 3.

CONCLUSION

Hyperbaric oxygen enhanced the healing of ischemic anastomoses in rats and improved the postoperative kidney function.

Pharmacological interventions for improved colonic anastomotic healing: A meta-analysis

AIM: To identify pharmaceuticals for the prophylaxis of anastomotic leakage (AL), we systematically reviewed studies on anastomosis repair after colorectal surgery.

METHODS: We searched PubMed and EMBASE for articles published between January 1975 and December 2012. We included studies in English with the primary purpose of promoting healing of anastomoses made in the colon or rectum under uncomplicated conditions. We excluded studies on adverse events from interventions, nutritional interventions or in situ physical supporting biomaterials. The primary outcome was biomechanical strength or AL. We performed meta-analyses on therapeutic agents investigated by three or more independent research groups using the same outcome. The DerSimonian-Laird method for random effects was applied with P < 0.05.

RESULTS: Of the 56 different therapeutic agents assessed, 7 met our inclusion criteria for the meta-analysis. The prostacyclin analog iloprost increased the weighted mean of the early bursting pressure of colonic anastomoses in male rats by 60 mmHg (95%CI: 30-89) vs the controls, and the immunosuppressant tacrolimus increased this value by 29 mmHg (95%CI: 4-53) vs the controls. Erythropoietin showed an enhancement of bursting pressure by 45 mmHg (95%CI: 14-76). The anabolic compound growth hormone augmented the anastomotic strength by 21 mmHg (95%CI: 7-35), possibly via the up-regulation of insulin-like growth factor-1, as this growth factor increased the bursting pressure by 61 mmHg (95%CI: 43-79) via increased collagen deposition. Hyperbaric oxygen therapy increased the bursting pressure by 24 mmHg (95%CI: 13-34). Broad-spectrum matrix metalloproteinase inhibitors increased the bursting pressure by 48 mmHg (95%CI: 31-66) on postoperative days 3-4. In the only human study, the AL incidence was not significantly reduced in the 103 colorectal patients treated with aprotinin (11.7%) compared with the 113 placebo-treated patients (9.7%).

CONCLUSION: This systematic review identified only one randomized clinical trial and seven therapeutic agents from pre-clinical models that could be explored further for the prophylaxis of AL after colorectal surgery.

The effects of hyperbaric oxygen therapy on experimental colon anastomosis after preoperative chemoradiotherapy

The aim of the present study was to investigate the effect of hyperbaric oxygen therapy (HBOT) on colon anastomosis after chemoradiotherapy (CRT). Sixty female Wistar-Albino rats were divided into 5 groups and underwent left colon resection and end-to-end anastomosis. CRT simulation was performed on 2 sham groups before the anastomosis, and 1 of these groups was administered additional postoperative HBOT. Two groups were administered CRT before the anastomosis, and 1 of them received additional postoperative HBOT. On postoperative day 5, all groups underwent relaparotomy; burst pressure was measured and samples were obtained for histopathologic and biochemical analysis. There was a significant weight loss in the CRT groups and postoperative HBOT had an improving effect. Significantly decreased burst pressure values increased up to the levels of the controls after HBOT. Hydroxyproline levels were elevated in all groups compared to the control group. Hydroxyproline levels decreased with HBOT after CRT. No significant difference was observed between the groups regarding fibrosis formation at the anastomosis site. However, regression was observed in fibrosis in the group receiving HBOT after CRT. Preoperative CRT affected anastomosis and wound healing unfavorably. These unfavorable effects were alleviated by postoperative HBOT. HBOT improved the mechanical and biochemical parameters of colon anastomosis in rats.

Complications of colorectal anastomoses: leaks, strictures, and bleeding

Intestinal anastomosis is an essential part of surgical practice, and with it comes the inherent risk of complications including leaks, strictures, and bleeding, which result in significant morbidity and occasional mortality. Understanding the myriad of risk factors and the strength of the data helps guide a surgeon as to the safety of undertaking an operation in which a primary anastomosis is to be considered. This article reviews the risk factors, management, and outcomes associated with anastomotic complications.

Hyperbaric oxygen therapy and mechanical resistence of the colonics anastomosis in rats with peritonitis

PURPOSE

To analyze the effects of hyperbaric oxygen therapy (HBO) on the mechanical resistance of anastomosis performed in rats' distal colon presenting peritonitis induced by ligature and cecal punction using the Total Energy Rupture biomechanical test (ETR).

METHODS

It was used 45 rats divided into three groups of 15 animals each. In Control Group (CG), it was performed anastomosis in distal colon without peritonitis. In Peritonitis Group (PG), it was performed anastomosis six hours after the induction of peritonitis by ligature and cecal punction. In Hyperbaric Chamber Group (HCG), it was performed six hours after the induction of peritonitis by ligature and cecal punction. The animals on CG and PG were kept at place air while the animals on HCG were placed on an experimental hyperbaric chamber in order to inhale oxygen at 100%, two absolute atmospheres, for 120 minutes, for four consecutive days. Euthanasia took place on the fifth day of the experiment. All the animals underwent to Total Energy Rupture Biomechanical Resistance test (ETR). Total Energy Rupture was defined as the necessary internal energy stored up to promote the colon rupture after an external traction force imposition.

RESULTS

The Peritonitis Group presents smaller average ETR than Control Group. There was no statistical difference between Peritonitis Group and Hyberbaric Chamber Group.

CONCLUSION

Hyperbaric oxygen therapy did not alter the mechanical resistance of anastomosis performed in distal colon of rats under the presence of peritonitis induced by ligature and cecal puncture.

Temperature control and the role of supplemental oxygen

Unrecognized and untreated intraoperative hypothermia remains a common avoidable scenario in the modern operating room. Failure to properly address this seemingly small aspect of the total operative care has been shown to have profound negative patient consequences including increased incidence of postoperative discomfort, surgical bleeding, requirement of allogenic blood transfusion, wound infections, and morbid cardiac events. All of these ultimately lead to longer hospitalizations and higher mortality. To avoid such problems, simple methods can be employed by the surgeon, anesthesiologist, and ancillary personnel to ensure euthermia. Similarly, another effortless method to potentially improve surgical outcomes is the liberal use of supplemental oxygen. Promising preliminary data suggests that high-concentration oxygen during and after surgery may decrease the rate of surgical site infections and gastrointestinal anastomotic failure. The precise role of supplemental oxygen in the perioperative period represents an exciting area of potential research that awaits further validation and analysis. In this article, the authors explore the data regarding both temperature regulation and supplemental oxygen use in an attempt to define further their emerging role in the perioperative care of patients undergoing colorectal surgery.

Effect of hyperbaric oxygen therapy on esophagojejunal anastomosis healing in rats

PURPOSE

To evaluate hyperbaric oxygen therapy (HBO) after esophagojejunal anastomosis in a rat experimental model and the effect of HBO on the healing of esophagojejunal anastomosis in gastrectomized rats.

METHODS

Forty adult male Wistar rats, weighing 322 g to 506 g, were divided into two random groups. In group A (control group), 20 rats were subjected to total gastrectomy. In group B, 20 rats were similarly gastrectomized, but also received postoperative HBO treatment for 90 minutes/day for seven days. All rats were sacrificed on the eighth postoperative day and evaluated according to the following study variables: a) presence of anastomotic fistula; b) evaluation of esophagojejunal anastomosis healing by measuring the breaking strength at the suture line as per Hendriks & Mastboom; and c) determining the collagen concentration in the anastomosis, as per Kovács criteria. For the comparative statistical analysis between groups, Student's "t" test was used. A value of p<0.05 was considered significant.

RESULTS

There was a 20% mortality rate. There were five deaths in group A and three in group B (p=N.S.). There was only one anastomotic fistula in each group, and neither caused any morbidity or death. Breaking strength measured at the suture line (p=0.528) and collagen concentration determined at the esophagojejunal anastomosis (p=0.89) were not significantly different between Groups A and B.

CONCLUSION

Hyperbaric oxygen therapy did not affect the healing process of esophagojejunal anastomosis.

Effects of platelet-rich plasma on intestinal wound healing in pigs

Anastomotic dehiscence and leakage remain a major problem in gastrointestinal surgery. Recently, attention has been focused on cellular acceleration of the wound healing process using platelet-rich plasma (PRP) and this study reports the effects of PRP on intestinal wound healing in pigs. Autologous PRP was obtained from 35 pigs that were then subjected to two intestinal anastomosis procedures. Activated PRP was applied at one of the anastomosis sites, while the other site served as control. After 24, 48, 72 and 96 h and then at 7 days, histology was performed and wound breaking strength was measured at 72 h and 7 days. PRP application appeared to increase granulation tissue and fibrosis, but did not influence anastomotic breaking strength.

Supplementation with High-Dose Ascorbic Acid Improves Intestinal Anastomotic Healing

BACKGROUND/AIM

Ascorbic acid modulates tissue healing but the value of ascorbic acid supplementation during anastomotic healing remains unclear. We examined the role of ascorbic acid treatment in experimental intestinal resection.

METHODS

Male Wistar albino rats (n = 30) were divided into three groups: sham treatment (group 1), and daily ascorbic acid treatment with 100 mg/kg (group 2) or 200 mg/kg (group 3) via the intramuscular route. Following sacrifice on the 7th postoperative day, bursting pressure of the anastomoses was measured. Hydroxyproline assessment and histological analysis were carried out.

RESULTS

The bursting pressure values of groups 2 (171.4 +/- 4.3 mm Hg) and 3 (196.4 +/- 2.2 mm Hg) were higher than that of group 1 (139.1 +/- 4.1 mm Hg; p < 0.05). In addition, the hydroxyproline level of group 3 (249.2 +/- 25.1 microg/mg) was higher than that of groups 1 (157.9 +/- 14.9 microg/mg) and 2 (187.9 +/- 14.8 microg/mg; p < 0.05). The histopathological scores indicated improved healing in groups 3 (6.0 +/- 0.2) and 2 (4.4 +/- 0.4), compared to group 1 (2.7 +/- 0.3; p < 0.05).

CONCLUSION

In the present study, supraphysiologic doses of ascorbic acid improved anastomotic healing. Therefore, vitamin C supplementation poses as a beneficial treatment in the context of collagen accumulation, inflammatory response, and anastomotic strength. However, the clinical value of high-dose ascorbic acid supplementation in the clinical setting is yet to be established.