Microcirculatory Dysfunction in Endotoxemic Bowel Anastomosis: The Pathogenetic Contribution of Microcirculatory Dysfunction to Endotoxemia-Induced Healing Impairment

Impact of postoperative NSAIDs administration on anastomotic leak after esophago-gastric surgery: systematic review and meta-analysis

Anastomotic leak (AL) is a feared complication of esophago-gastric surgery. Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to treat postoperative pain. Previous analyses conveyed heterogeneous data for colorectal surgery with a tendency toward high risk for AL after NSAIDs administration. In the setting of upper gastrointestinal (GI) surgery data are even more puzzled. The purpose of the present study was to assess whether an association exists between postoperative NSAIDs administration and AL after esophago-gastric surgery. PubMed, MEDLINE, Scopus, and Web of Science were searched up to November 2022. The included studies evaluated outcomes for NSAIDs vs. no NSAIDs administration after esophago-gastric surgery. The primary outcome was anastomotic leak (AL). Risk ratio (RR) and 95% confidence intervals (95% CI) were used to assess pooled effect size and relative inference. Six studies (43,784 patients) were included. The patient age ranged from 31 to 84 years, 82.4% were males and preoperative BMI ranged from 15 to 31 kg/m². Esophagectomy was performed in 95% of patients. NSAIDs were administered in 18,075 (41.3%) patients. The cumulative incidence of AL was similar for NSAIDs vs. no NSAIDs (13.6% vs. 13.4%). The risk for postoperative AL was similar for NSAIDs vs. no NSAIDs administration (RR 1.49; 95% CI 0.81-2.75; p = 0.19). The cumulative incidence of postoperative gastrointestinal bleeding (0.36% vs. 0.39%), acute kidney injury (0.62% vs. 0.71%), and in-hospital mortality (2.39% vs. 2.66%) were comparable. NSAIDs administration for postoperative analgesia seems not associated with an increased risk for AL after esophago-gastric surgery.

Updates of Risk Factors for Anastomotic Leakage after Colorectal Surgery

Anastomotic leakage is a potentially severe complication occurring after colorectal surgery and can lead to increased morbidity and mortality, permanent stoma formation, and cancer recurrence. Multiple risk factors for anastomotic leak have been identified, and these can allow for better prevention and an earlier diagnosis of this significant complication. There are nonmodifiable factors such as male gender, comorbidities and distance of tumor from anal verge, and modifiable risk factors, including smoking and alcohol consumption, obesity, preoperative radiotherapy and preoperative use of steroids or non-steroidal anti-inflammatory drugs. Perioperative blood transfusion was shown to be an important risk factor for anastomotic failure. Recent studies on the laparoscopic approach in colorectal surgery found no statistical difference in anastomotic leakage rate compared with open surgery. A diverting stoma at the time of primary surgery does not appear to reduce the leak rate but may reduce its clinical consequences and the need for additional surgery if anastomotic leakage does occur. It is still debatable if preoperative bowel preparation should be used, especially for left colon and rectal resections, but studies have shown similar incidence of postoperative leak rate.

Ketorolac and Other NSAIDs Increase the Risk of Anastomotic Leakage After Surgery for GEJ Cancers: a Cohort Study of 557 Patients

OBJECTIVE

The objective of this study is to investigate the impact of ketorolac and other nonsteroidal anti-inflammatory drugs on anastomotic leakage after surgery for gastro-esophageal-junction cancer. Within the last two decades, the incidence of gastro-esophageal-junction cancer has increased in the western world and surgery is the curative treatment modality of choice. Anastomotic leakage is a feared complication of gastro-esophageal surgery, as it increases recurrence, morbidity, and mortality. Nonsteroidal anti-inflammatory drugs are widely used for postoperative pain relief. Nonsteroidal anti-inflammatory drugs have, however, in colorectal surgery, been shown to increase the risk of anastomotic leakage.

METHOD

In a historical cohort study, we investigated the impact of nonsteroidal anti-inflammatory drugs on anastomotic leakage in 557 patients undergoing surgery for gastro-esophageal-junction cancer. Data were collected from a prospective maintained database, the Danish National Patient Registry, and patient medical records. Data were analyzed using univariate and multivariate statistical models and were stratified for theoretical confounders.

RESULTS

In univariate analysis, we did not observe any difference in age, gender, tobacco exposure, or comorbidity status between patients experiencing anastomotic leakage and those without. In multivariate analysis, gender, histology, and type of anastomosis proved to affect odds ratios for anastomotic leakage. After adjustment for possible confounders, we found an odds ratio of 6.05 (95% confidence interval 2.71; 13.5) for ketorolac use and of 5.24 (95% confidence interval 1.85; 14.8) for use of other nonsteroidal anti-inflammatory drugs for anastomotic leakage during the first seven postoperative days.

CONCLUSION

In the present study, we found a strong association between the postoperative use of ketorolac and other nonsteroidal anti-inflammatory drugs and the risk for anastomotic leakage after surgery for gastro-esophageal-junction cancers.

Perioperative blood transfusions increases the risk of anastomotic leakage after surgery for GEJ-cancer

OBJECTIVE

To investigate the effect of blood transfusions on the risk of anastomotic leakage (AL) in patients with gastro-esophageal-junction (GEJ) cancer.

BACKGROUND

The incidence of GEJ cancer is increasing in the western world. Surgery is the curative treatment of choice. AL increases mortality and morbidity, and increases the risk cancer reoccurrence. In colo-rectal surgery a relation between AL and blood transfusions have been demonstrated.

METHOD

The risk of AL in relation to blood transfusions was investigated in a cohort study. 253 consecutive patients undergoing surgery for GEJ cancer was included. Data was based on a prospective maintained database and analyzed using logistic regressions models adjusting for multiple confounders.

RESULTS

We found an increased risk of AL when blood was transfused OR: 3.47, (1.51; 7.99). This relation was consistent after adjustment for multiple confounders OR: 4.60, (1.29; 16.4). Increasing number of blood units did not increase risk of AL further.

CONCLUSION

We present data demonstrating a strong correlation between receiving blood transfusions and the risk of AL after surgery in GEJ cancers patients.

Sidestream dark field imaging of the serosal microcirculation during gastrointestinal surgery

AIM

The study aimed to describe the serosal microcirculation of the human bowel using sidestream dark field imaging, a microscopic technique using polarized light to visualize erythrocytes through capillaries. We also compared its feasibility to the current practice of sublingual microcirculatory assessment.

METHOD

In 17 patients sidestream dark field measurements were performed during gastrointestinal surgery. Microcirculatory parameters like microvascular flow index (MFI), proportion of perfused vessels (PPV), perfused vessel density (PVD) and total vessel density (TVD) were determined for every patient, sublingually and on the bowel serosa.

RESULTS

Sixty measurements were done on the bowel of which eight (13%) were excluded, five owing to too much bowel peristalsis and three because of pressure artefacts. Image stability was in favour of sublingual measurements [pixel loss per image, bowel 145 (95% CI 126-164) vs sublingual 55 (95% CI 41-68); P < 0.001] and time to acquire a stable image [bowel 96 s (95% CI 63-129) vs. sublingual 46 s (95% CI 29-64); P = 0.013]. No difference in the MFI was observed [bowel 2.9 (interquartile range 2.87-2.95) vs sublingual 3.0 (interquartile range 2.91-3.0); P = 0.081]. There was a difference in the PPV [bowel 95% (95% CI 94-96) vs sublingual 97% (95% CI 97-99); P < 0.001], PVD [bowel 12.9 mm/mm2 (95% CI 11.1-14.8) vs sublingual 17.4 mm/mm2 (95% CI 15.6-19.1); P = 0.003] and the TVD [bowel 13.6 mm/mm2 (95% CI 11.6-15.6) vs sublingual 17.7 mm/mm2 (95% CI 16.0-19.4); P = 0.008].

CONCLUSION

Sidestream dark field imaging is a very promising technique for bowel microcirculatory visualization and assessment. It is comparable to sublingual assessment and the analysis produces a similar outcome with slightly differing anatomical features.

Sepsis is associated with altered cerebral microcirculation and tissue hypoxia in experimental peritonitis

OBJECTIVE

Alterations in cerebral microvascular blood flow may develop during sepsis, but the consequences of these abnormalities on tissue oxygenation and metabolism are not well defined. We studied the evolution of microvascular blood flow, brain oxygen tension (PbO2), and metabolism in a clinically relevant animal model of septic shock.

DESIGN

Prospective randomized animal study.

SETTING

University hospital research laboratory.

SUBJECTS

Fifteen invasively monitored and mechanically ventilated female sheep.

INTERVENTIONS

The sheep were randomized to fecal peritonitis (n = 10) or a sham procedure (n = 5), and craniectomies were performed to enable evaluation of cerebral microvascular blood flow, PbO2, and metabolism. The microvascular network of the left frontal cortex was evaluated (at baseline, 6, 12, and 18 hr) using sidestream dark-field videomicroscopy. Using an off-line semiquantitative method, functional capillary density and the proportion of small perfused vessels were calculated. PbO2 was measured hourly by a parenchymal Clark electrode, and cerebral metabolism was assessed by the lactate/pyruvate ratio using brain microdialysis; both these systems were placed in the right frontal cortex.

MEASUREMENT AND MAIN RESULTS

In septic animals, cerebral functional capillary density (from 3.1 ± 0.5 to 1.9 ± 0.4 n/mm, p < 0.001) and proportion of small perfused vessels (from 98% ± 2% to 84% ± 7%, p = 0.004) decreased over the 18-hour study period. Concomitantly, PbO2 decreased (61 ± 5 to 41 ± 7 mm Hg, p < 0.001) and lactate/pyruvate ratio increased (23 ± 5 to 36 ± 19, p < 0.001). At 18 hours, when shock was present, animals with a mean arterial pressure less than 65 mm Hg (n = 6) had similar functional capillary density, proportion of small perfused vessels, and PbO2 values but significantly higher lactate/pyruvate ratio (46 ± 18 vs 20 ± 4, p = 0.009) compared with animals with an mean arterial pressure of 65-70 mm Hg (n = 4).

CONCLUSIONS

Impaired cerebral microcirculation during sepsis is associated with progressive impairment in PbO2 and brain metabolism. Development of severe hypotension was responsible for a further increase in anaerobic metabolism. These alterations may play an important role in the pathogenesis of brain dysfunction during sepsis.

Comparison of intestinal microcirculation and wound healing in a rat model

PURPOSE

If a colonic or small bowel lesion is not accessible for endoscopic mucosal resection, enterotomy is a possible although rarely performed surgical technique. It has never been compared to circular anastomosis regarding leakage rate, bowel wall perfusion, and wound healing. Thus, the aim of this basic experimental scientific study was to investigate perianastomotic microcirculation and wound healing.

METHODS

Forty rats were divided into four groups (1 jejunal anastomosis, 2 jejunal enterotomy, 3 colonic anastomosis, and 4 colonic enterotomy). Following anastomosis and enterotomy, the intestinal perfusion was measured using laser fluorescence angiography (IC-View). On postoperative day 7, the surface of the mucosal villi, expression of matrix metalloproteinases (MMP) 2, 8, 9, and 13, and the number of proliferating cells (Ki67) as well as the collagen types I/III ratio were analyzed.

RESULTS

The perianastomotic microperfusion was significantly reduced in all groups compared to the reference region. The perianastomotic perfusion index was significantly reduced in group 1 compared with group 2, whereas the perfusion index in group 3 was slightly but not significantly reduced in comparison to group 4. Ki67 was elevated in both circular anastomosis groups. Surface of the mucosal villi, MMP expression, and collagen type I/III ratio revealed no significant differences.

CONCLUSIONS

Our study affirms the theoretical consideration of a better microperfusion of the bowel wall following an antimesenterial enterotomy and demonstrates that enterotomy is not inferior compared to circular anastomosis. Even though enterotomy is a rarely used surgical technique, it should be regarded as a possible alternative in particular situations.

Effects of eritoran tetrasodium, a toll-like receptor 4 antagonist, on intestinal microcirculation in endotoxemic rats

Lipopolysaccharide (LPS) or endotoxin can induce Toll-like receptor 4 signaling and cause microcirculatory dysfunction, which can lead to multiple organ dysfunction. The goal of this study was to investigate whether Toll-like receptor 4 antagonist, eritoran tetrasodium, can attenuate microcirculatory dysfunction in endotoxemic rats. Seventy-two male Wistar rats were divided into three groups as follows: control, LPS, and eritoran + LPS. These rats received laparotomy to exteriorize a segment of terminal ileum for microcirculation examination on intestinal mucosa, muscle, and Peyer patch. The rats in the eritoran + LPS group received 10 mg kg⁻¹ eritoran intravenously. The rats in the LPS and eritoran + LPS groups received 15 mg kg⁻¹ LPS intravenously. Microcirculatory blood flow intensity was measured by full-field laser perfusion imager. Total and perfused small-vessel densities, microvascular flow index, and heterogeneity index were investigated by sidestream dark-field video microscope. Our results revealed that eritoran restored the mean arterial pressure. At 240 min, the microcirculatory blood flow intensity was higher in the eritoran + LPS group than in the LPS group as follows: mucosa (1,094 [SD, 398] vs. 543 [SD, 163] perfusion unit [PU]; P < 0.001), muscle (752 [SD, 124] vs. 357 [SD, 208] PU; P < 0.001), and Peyer patch (961 [SD, 162] vs. 480 [SD, 201] PU; P < 0.001). Eritoran also attenuated endotoxin-induced elevation in the serum level of D-dimer. In conclusion, we have established a promising rat protocol to investigate the intestinal microcirculation in endotoxemia. Our data indicate that eritoran can reduce microcirculatory dysfunction in endotoxemic rats.

Correlation between early sublingual small vessel density and late blood lactate level in critically ill surgical patients

BACKGROUND

Surgical stress may cause excessive inflammation and lead to microcirculatory dysfunction. The hypothesis of this study was that early microcirculatory dysfunction may result in anaerobic glycolysis and lead to elevated blood lactate levels in patients admitted to surgical intensive care units.

METHODS

This prospective observational study enrolled adult patients admitted to surgical intensive care units after general surgery or thoracic surgery. We measured blood lactate levels before the operation and at 1 h and 24 h after the operation. We obtained images of sublingual microcirculation using a sidestream dark field video microscope and analyzed them employing automated analysis software.

RESULTS

A total of 31 patients completed the study. Perioperative total and perfused small vessel densities were lower in patients with a blood lactate level ≥3 mmol/L. We observed a significant correlation between the total small vessel density at 1 h and the blood lactate level at 24 h (r = -0.573; P = 0.001). In addition, we saw a significant correlation between the perfused small vessel density at 1 h and the blood lactate level at 24 h (r = -0.476; P = 0.008).

CONCLUSIONS

Early total and perfused small vessel density may be used as an early predictor or therapeutic goal for critically ill surgical patients in further studies.