Intraoperative measurement of colonic oxygenation during bowel resection

"It just wasn't right down there": Surgical treatment of small bowel evisceration after hysterectomy with indocyanine green angiography, a case report

This is a case of a 70-year-old female with small bowel evisceration through vaginal cuff dehiscence 14 months after hysterectomy. She presented with a loop of ileum herniated through the vagina. The bowel was irreducible and she was taken to the operating room for exploratory laparotomy, reduction of herniated bowel contents, and repair of vaginal cuff. During surgery, the eviscerated bowel had questionable viability and indocyanine green angiography was used to assess perfusion. After the repair of the vaginal cuff, indocyanine green angiography was performed and the bowel was saved from resection. In the discussion, light is shed upon the rarity of vaginal cuff dehiscence and the few cases of small bowel evisceration after a dehiscence. Possible causes of the evisceration, updates to technique, and recommendations for management are also discussed. The ultimate recommendation is for use of indocyanine green angiography in assessment of intestinal viability during surgical exploration for small bowel evisceration.

The Safe Values of Quantitative Perfusion Parameters of ICG Angiography Based on Tissue Oxygenation of Hyperspectral Imaging for Laparoscopic Colorectal Surgery: A Prospective Observational Study

BACKGROUND

Safe values for quantitative perfusion parameters of indocyanine green (ICG) angiography have not been fully defined, and interpretation remains at the surgeon's discretion. This prospective observational study aimed to establish the safe values for the quantitative perfusion parameters by comparing tissue oxygenation levels from HSI images in laparoscopic colorectal surgery.

METHODS

ICG angiography was performed using a laparoscopic near-infrared (NIR) camera system with ICG diluted in 10 mL of distilled water. For quantitative perfusion parameters, the changes in fluorescence intensity with perfusion times were analyzed to plot a time-fluorescence intensity graph. To assess real-time tissue oxygen saturation (StO2) in the colon, the TIVITA® Tissue System was utilized for hyperspectral imaging (HSI) acquisition. The StO2 levels were compared with the quantitative perfusion parameters derived from ICG angiography at corresponding points to define the safe range of ICG parameters reflecting good tissue oxygenation.

RESULTS

In the regression analysis, T1/2MAX, TMAX, slope, and NIR perfusion index were correlated with tissue oxygen saturation. Using this regression model, the cutoff values of quantitative perfusion parameters were calculated as T1/2MAX ≤ 10 s, TMAX ≤ 30 s, slope ≥ 5, and NIR perfusion index ≥50, which best reflected colon StO2 higher than 60%. Diagnostic values were analyzed to predict colon StO2 of 60% or more, and the ICG perfusion parameters T1/2MAX, TMAX, and perfusion TR showed high sensitivity values of 97% or more, indicating their ability to correctly identify cases with acceptable StO2.

CONCLUSION

The safe values for quantitative perfusion parameters derived from ICG angiography were T1/2MAX ≤ 10 s and TMAX ≤ 30 s, which were associated with colon tissue oxygenation levels higher than 60% in the laparoscopic colorectal surgery.

Novel Modality of Endoluminal Anastomotic Integrity Assessment with Fluoroangiography After Left-sided Colorectal Resections

BACKGROUND

Several methods have been described for the intraoperative evaluation of colorectal anastomotic integrity. Technological evolution has allowed to progress from basic mechanical methods to the use of more sophisticated techniques. This study describes a novel endoluminal modality of colorectal anastomotic assessment through the use of a Disposable Rigid Scope Introducer (DRSI) also allowing for intraoperative endoluminal perfusion evaluation by indocyanine green (ICG) fluoroangiography in patients undergoing left-sided colorectal resection.

METHODS

The DRSI consists of an endoluminal introducer device made up of an insertion tube and port connected to an insufflation bulb to manually insufflate the sigmoid and rectum and is compatible with any laparoscopic camera, also allowing for ICG fluoroangiography for perfusion purposes.

RESULTS

The DRSI was successfully used to assess anastomotic integrity after left-sided colorectal resections performed in 16 consecutive patients. The DRSI allowed to visualize by fluoroangiography the quality of tissue perfusion at the anastomotic site in all cases, contributing to the decision of avoiding loop ileostomies in low rectal resections. In 2 cases, the DRSI showed the presence of significant anastomotic bleeding which was successfully controlled by laparoscopic suture placement. No adverse event resulted from the use of this device.

CONCLUSIONS

The DRSI combines direct endoluminal visualization of the anastomosis together with real-time evaluation of its blood flow. This device holds great potential for prompt intraoperative detection of anastomotic alterations, possibly reducing the risk of postoperative anastomotic bleeding or leaks related to mechanical construction/perfusion issues. Potential advantages of this device warrant larger cohort studies and prospective randomized trials.

Assessment of Intestinal Ischemia-Reperfusion Injury Using Diffuse Reflectance VIS-NIR Spectroscopy and Histology

A porcine model was used to investigate the feasibility of using VIS-NIR spectroscopy to differentiate between degrees of ischemia-reperfusion injury in the small intestine. Ten pigs were used in this study and four segments were created in the small intestine of each pig: (1) control, (2) full arterial and venous mesenteric occlusion for 8 h, (3) arterial and venous mesenteric occlusion for 2 h followed by reperfusion for 6 h, and (4) arterial and venous mesenteric occlusion for 4 h followed by reperfusion for 4 h. Two models were built using partial least square discriminant analysis. The first model was able to differentiate between the control, ischemic, and reperfused intestinal segments with an average accuracy of 99.2% with 10-fold cross-validation, and the second model was able to discriminate between the viable versus non-viable intestinal segments with an average accuracy of 96.0% using 10-fold cross-validation. Moreover, histopathology was used to investigate the borderline between viable and non-viable intestinal segments. The VIS-NIR spectroscopy method together with a PLS-DA model showed promising results and appears to be well-suited as a potentially real-time intraoperative method for assessing intestinal ischemia-reperfusion injury, due to its easy-to-use and non-invasive nature.

The use of fluorescence angiography to assess bowel viability in the acute setting: an international, multi-centre case series

Introduction

Assessing bowel viability can be challenging during acute surgical procedures, especially regarding mesenteric ischaemia. Intraoperative fluorescence angiography (FA) may be a valuable tool for the surgeon to determine whether bowel resection is necessary and to define the most appropriate resection margins. The aim of this study is to report on FA use in the acute setting and to judge its impact on intraoperative decision making.

Materials and methods

This is a multi-centre, retrospective case series of patients undergoing emergency abdominal surgery between February 2016 and 2021 in three general/colorectal units where intraoperative FA was performed to assess bowel viability. Primary endpoint was change of management after the FA assessment.

Results

A total of 93 patients (50 males, 66.6 ± 19.2 years, ASA score ≥ III in 85%) were identified and studied. Initial surgical approach was laparotomy in 66 (71%) patients and laparoscopy in 27 (29% and seven, 26% conversions). The most common aetiologies were mesenteric ischaemia (n = 42, 45%) and adhesional/herniae-related strangulation (n = 41, 44%). In 50 patients a bowel resection was performed. Overall rates of anastomosis after resection, reoperation and 30-day mortality were 48% (n = 24/50, one leak), 12% and 18%, respectively. FA changed management in 27 (29%) patients. In four patients (4% overall), resection was avoided and in 21 (23%) extra bowel length was preserved (median 50 cm of bowel saved, IQR 28–98) although three patients developed further ischaemia. FA prompted extended resection (median of 20 cm, IQR 10–50 extra bowel) in six (6%) patients.

Conclusion

Intraoperative use of FA impacts surgical decisions regarding bowel resection for intestinal ischaemia, potentially enabling bowel preservation in approximately one out of four patients. Prospective studies are needed to optimize the best use of this technology for this indication and to determine standards for the interpretation of FA images and the potential subsequent need for second-look surgeries.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-022-09136-7.

Intraoperative colon perfusion assessment using multispectral imaging

In colorectal surgery an anastomosis performed using poorly-perfused, ischaemic bowel segments may result in a leak and consequent morbidity. Traditional measures of perfusion assessment rely on clinical judgement and are mainly subjective, based on tissue appearance, leading to variability between clinicians. This paper describes a multispectral imaging (MSI) laparoscope that can derive quantitative measures of tissue oxygen saturation (SO₂ ). The system uses a xenon surgical light source and fast filter wheel camera to capture eight narrow waveband images across the visible range in approximately 0.3 s. Spectral validation measurements were performed by imaging standardised colour tiles and comparing reflectance with ground truth spectrometer data. Tissue spectra were decomposed into individual contributions from haemoglobin, adipose tissue and scattering, using a previously-developed regression approach. Initial clinical results from seven patients undergoing colorectal surgery are presented and used to characterise measurement stability and reproducibility in vivo. Strategies to improve signal-to-noise ratio and correct for motion are described. Images of healthy bowel tissue (in vivo) indicate that baseline SO₂ is approximately 75 ± 6%. The SO₂ profile along a bowel segment following ligation of the inferior mesenteric artery (IMA) shows a decrease from the proximal to distal end. In the clinical cases shown, imaging results concurred with clinical judgements of the location of well-perfused tissue. Adipose tissue, visibly yellow in the RGB images, is shown to surround the mesentery and cover some of the serosa. SO₂ in this tissue is consistently high, with mean value of 90%. These results show that MSI is a potential intraoperative guidance tool for assessment of perfusion. Mapping of SO₂ in the colon could be used by surgeons to guide choice of transection points and ensure that well-perfused tissue is used to form an anastomosis. The observation of high mesenteric SO₂ agrees with work in the literature and warrants further exploration. Larger studies incorporating with a wider cohort of clinicians will help to provide retrospective evidence of how this imaging technique may be able to reduce inter-operator variability.

Simultaneous computer-assisted assessment of mucosal and serosal perfusion in a model of segmental colonic ischemia

BACKGROUND

Fluorescence-based enhanced reality (FLER) enables the quantification of fluorescence signal dynamics, which can be superimposed onto real-time laparoscopic images by using a virtual perfusion cartogram. The current practice of perfusion assessment relies on visualizing the bowel serosa. The aim of this experimental study was to quantify potential differences in mucosal and serosal perfusion levels in an ischemic colon segment.

METHODS

An ischemic colon segment was created in 12 pigs. Simultaneous quantitative mucosal and serosal fluorescence imaging was obtained via intravenous indocyanine green injection (0.2 mg/kg), using two near-infrared camera systems, and computer-assisted FLER analysis. Lactate levels were measured in capillary blood of the colonic wall at seven regions of interest (ROIs) as determined with FLER perfusion cartography: the ischemic zone (I), the proximal and distal vascularized areas (PV, DV), and the 50% perfusion threshold proximally and distally at the mucosal and serosal side (P50M, P50S, D50M, D50S).

RESULTS

The mean ischemic zone as measured (mm) for the mucosal side was significantly larger than the serosal one (56.3 ± 21.3 vs. 40.8 ± 14.9, p = 0.001) with significantly lower lactate values at the mucosal ROIs. There was a significant weak inverse correlation between lactate and slope values for the defined ROIs (r = - 0.2452, p = 0.0246).

CONCLUSIONS

Mucosal ischemic zones were larger than serosal zones. These results suggest that an assessment of bowel perfusion from the serosal side only can underestimate the extent of ischemia. Further studies are required to predict the optimal resection margin and anastomotic site.

Does intra-operative flexible endoscopy reduce anastomotic complications following left-sided colonic resections? A systematic review and meta-analysis

AIM

Postoperative anastomotic leakage (AL) or bleeding (AB) significantly impacts on patient outcome following colorectal resection. To minimize such complications, surgeons can utilize different techniques perioperatively to assess anastomotic integrity. We aim to assess published anastomotic complication rates following left-sided colonic resection, comparing the use of intra-operative flexible endoscopy (FE) against conventional tests used to assess anastomotic integrity.

METHODS

PubMed/MEDLINE and Embase online databases were searched for non-randomized and randomized case-control studies that investigated postoperative AL and/or AB rates in left-sided colonic resections, comparing intra-operative FE against conventional tests. Data from eligible studies were pooled, and a meta-analysis using Review Manager 5.3 software was performed to assess for differences in AL and AB rates.

RESULTS

Data from six studies were analysed to assess the impact of FE on postoperative AL and AB rates (1084 and 751 patients respectively). Use of FE was associated with reduced postoperative AL and AB rates, from 6.9% to 3.5% and 5.8% to 2.4% respectively. Odds ratios favoured intra-operative FE: 0.37 (95% CI 0.21-0.68, P = 0.001) for AL and 0.35 (95% CI 0.15-0.82, P = 0.02) for AB.

CONCLUSION

This meta-analysis showed that the use of intra-operative FE is associated with a reduced rate of postoperative AL and AB, compared to conventional anastomotic testing methods.

Dexamethasone protects the glycocalyx on the kidney microvascular endothelium during severe acute pancreatitis

OBJECTIVE

This study demonstrated that dexamethasone (DEX) protects the endothelial glycocalyx from damage induced by the inflammatory stimulus tumor necrosis factor-α (TNF-α) during severe acute pancreatitis (SAP), and improves the renal microcirculation.

METHODS

Ninety mice were evenly divided into 3 groups (Sham, SAP, and SAP+DEX). The SAP mice model was established by ligature of pancreatic duct and intraperitoneal injection of cerulein. Renal perfusion and function, and morphological changes of the glycocalyx were evaluated by laser Doppler velocimetry, electron microscopy, and histopathology (hematoxylin and eosin (H&E) staining), respectively. Serum levels of syndecan-1 and TNF-α were assessed by enzyme-linked immunosorbent assay (ELISA). The protective effects of dexamethasone on the glycocalyx and renal microcirculation were evaluated.

RESULTS

Significantly high levels of serum TNF-α were detected 3 h after the onset of SAP. These levels might induce degradation of the glycocalyx and kidney hypoperfusion, resulting in kidney microcirculation dysfunction. The application of dexamethasone reduced the degradation of the glycocalyx and improved perfusion of kidney.

CONCLUSIONS

Dexamethasone protects the endothelial glycocalyx from inflammatory degradation possibly initiated by TNF-α during SAP. This is might be a significant discovery that helps to prevent tissue edema and hypoperfusion in the future.

Indocyanine Green Tissue Angiography Can Reduce Extended Bowel Resections in Acute Mesenteric Ischemia

PURPOSE

Surgical exploration and bowel resection are frequently required for treating non-occlusive mesenteric ischemia. Intraoperative evaluation of intestinal perfusion is subjective and challenging. In this feasibility study, ICG fluorescence angiography was performed in order to evaluate intestinal perfusion in patients with acute mesenteric ischemia.

METHODS

This is a retrospective analysis of 52 patients who were operated for acute mesenteric ischemia using ICG fluorescence angiography. Patients with occlusive disease requiring recanalization were excluded. The SPY and PinPoint imaging systems were used for open and laparoscopic surgery, respectively. Intraoperative macroscopic assessment of perfusion was compared with the ICG angiography results.

RESULTS

Surgical exploration was performed for ischemia of the colon (n = 12), the small bowel (n = 23), or both (n = 16). One patient had ischemia of the esophagus and stomach. All patients had a preoperative CT angiography to rule out stenosis or occlusion of the mesenteric vessels. In 18 cases (34.6%), ICG fluorescence angiography provided information that was supplemental to macroscopic evaluation, but most patients did not survive the postoperative course. However, in six of those cases (11.5%), ICG angiography led to a major change in operative strategy resulting in a significant clinical benefit for those patients. For two cases, ICG fluorescence produced false negative results.

DISCUSSION

ICG tissue angiography is feasible and technically reliable for evaluating intestinal perfusion in acute mesenteric ischemia and led to a significant clinical benefit in 11% of our patients. A relevant discrepancy between surgical visual assessment and fluorescence angiography was found in 35% of the cases, which may help to define resection margins more accurately and thus support surgical decision-making.

Can sidestream dark field (SDF) imaging identify subtle microvascular changes of the bowel during colorectal surgery?

BACKGROUND

Recognition of a non-viable bowel during colorectal surgery is a challenging task for surgeons. Identifying the turning point in serosal microcirculatory deterioration leading up to a non-viable bowel is crucial. The aim of the present study was to determine whether sidestream darkfield (SDF) imaging can detect subtle changes in serosal microcirculation of the sigmoid after vascular transection during colorectal surgery.

METHODS

A prospective observational clinical study was performed at a single medical centre. All eligible participants underwent laparoscopic sigmoid resection and measurements were taken during the extra-abdominal phase. Microcirculation was measured at the transected bowel and 20 cm proximal to this point. Microcirculatory parameters such as Microvascular Flow Index (MFI), proportion of perfused vessels (PPV), perfused vessel density (PVD), total vessel density (TVD) and the Heterogeneity Index were determined. Data are presented as median (interquartile range) or mean ± standard deviation.

RESULTS

A total of 60 SDF images were acquired for 10 patients. Perfusion parameters and perfused vessel density were significantly lower at the transected bowel compared with the non-transected measurements [MFI 2.29 (1.96-2.63) vs 2.96 (2.73-3.00), p = 0.007; PPV 74% (55-83) vs 94% (86-97), p = 0.007; and PVD 7.61 ± 2.99 mm/mm² versus 10.67 ± 1.48 mm/mm², p = 0.009]. Total vessel density was similar between the measurement locations.

CONCLUSIONS

SDF imaging can identify changes of the bowel serosal microcirculation. Significantly lower serosal microcirculatory parameters of the vascular transected bowel was seen compared with the non-transected bowel. The ability of SDF imaging to detect subtle differences holds promise for future research on microvascular cut-off values leading to a non-viable bowel.

Fluorescence in robotic surgery

Currently, there are several clinical applications for intraoperative ICG, such as identification of vascular and biliary anatomy, assessment of organ and tissue perfusion, lymph node mapping, and real-time identification of lesions. In this paper we present a review of the available literature related to the use of ICG fluorescence in robotic surgery in order to provide a better understanding of the current applications, show the rapid growth of this technique, and demonstrate the potential future applications.

Intraoperative assessment of colorectal anastomotic integrity: a systematic review

BACKGROUND

Surgeons have attempted to minimize postoperative anastomotic complications by employing intraoperative tests and manoeuvres to assess colorectal anastomotic integrity. These have evolved over time with improvement in operative technology and techniques. This systematic review aims to examine the impact of such intraoperative assessments.

METHODS

A systematic review of studies assessing intraoperative anastomotic assessments and their impact on postoperative anastomotic complications was performed. Intraoperative measures undertaken as a result of intraoperative assessments and postoperative anastomotic complications were analysed.

RESULTS

37 Studies were identified. 13 studies evaluated basic mechanical patency tests, ten studies evaluated endoscopic visualisation techniques and 14 studies evaluated microperfusion techniques. Postoperative anastomotic complications were significantly lower in patients tested with basic mechanical patency tests compared to those untested (non-RCT: 4.1 vs. 8.1 %, p = 0.03, RCTs: 5.8 vs. 16.0 %, p = 0.024). There were no differences in postoperative anastomotic complications between tested and non-tested cohorts in non-randomised cohort studies evaluating endoscopic visualisation techniques. However, intraoperative measures taken after abnormal intraoperative tests may have reduced the number of postoperative complications. Perfusion analysis techniques are not in routine widespread clinical practice as yet, but newer techniques such as fluorescent dyes and imaging under near infrared light show technical feasibility.

CONCLUSIONS

Intraoperative colorectal anastomotic assessment has evolved together with advancement of technology in the surgical setting. Moderate benefit in terms of lower postoperative anastomotic complications has been shown with basic mechanical patency testing and more recently with intraoperative endoscopic visualisation of colorectal anastomoses. The next advance and possible introduction into routine practice may include the use of microperfusion techniques. The latest in this group of techniques, which utilise autofluorescent dyes such as Indocyanine green, hold great potential. Well-planned controlled studies or ideally, randomised controlled trials need to be conducted to further assess the benefit of these latest techniques.

Proximal bowel necrosis after high ligation of the inferior mesenteric artery in colorectal surgery

BACKGROUND AND AIMS

High ligation of the inferior mesenteric artery may jeopardize blood supply to the proximal bowel. We undertook this study to review the clinical features and outcomes of patients who developed proximal bowel necrosis after high ligation of the inferior mesenteric artery, and to assess the incidence and the risk factors for this complication.

MATERIALS AND METHODS

A retrospective analysis of patients undergoing high or low ligation for sigmoid colon and rectal cancer with a primary anastomosis between April 2004 and March 2009 was performed. Patient and tumor characteristics and the incidence of bowel necrosis were reviewed.

RESULTS

Four hundred and nine patients were included to the analysis. Six out of 302 patients (2.0%) with high ligation developed proximal bowel necrosis, while the remaining 107 patients with low ligation did not suffer from this complication. All patients who developed proximal bowel necrosis underwent secondary surgery with resection of necrotic bowel. The pathological examination of the resected specimen revealed mucosal to transmural ischemic necrosis without the evidence of vascular thrombosis or embolic occlusion. Univariate analysis revealed that advanced age, cerebrovascular disease, and hypertension were significantly associated with proximal bowel necrosis. Multivariate analysis demonstrated that cerebrovascular disease was an independent predictor of this complication. Of these six patients, two died from associated complications.

CONCLUSIONS

Proximal bowel necrosis after high ligation is potentially fatal, and this report provides a warning in clinical settings where high ligation is indicated. Further studies are warranted to evaluate its distinct relationship with high ligation and to clarify whether low ligation would be a safeguard.

How to assess intestinal viability during surgery: A review of techniques

Objective and quantitative intraoperative methods of bowel viability assessment are essential in gastrointestinal surgery. Exact determination of the borderline of the viable bowel with the help of an objective test could result in a decrease of postoperative ischemic complications. An accurate, reproducible and cost effective method is desirable in every operating theater dealing with abdominal operations. Numerous techniques assessing various parameters of intestinal viability are described by the studies. However, there is no consensus about their clinical use. To evaluate the available methods, a systematic search of the English literature was performed. Virtues and drawbacks of the techniques and possibilities of clinical application are reviewed. Valuable parameters related to postoperative intestinal anastomotic or stoma complications are analyzed. Important issues in the measurement and interpretation of bowel viability are discussed. To date, only a few methods are applicable in surgical practice. Further studies are needed to determine the limiting values of intestinal tissue oxygenation and flow indicative of ischemic complications and to standardize the methods.

Decreased conduit perfusion measured by spectroscopy is associated with anastomotic complications

BACKGROUND

Gastric conduit ischemia during esophagectomy likely contributes to high anastomotic complication rates, yet we lack a reliable method to assess gastric conduit perfusion. We hypothesize that optical fiber spectroscopy (OFS) can reliably assess conduit perfusion and that the degree of intraoperative gastric ischemia is associated with subsequent anastomotic complications.

METHODS

During esophagectomy, OFS was used to measure oxygen saturation (SaO(2)) and blood volume fraction (BVF) in the distal gastric conduit at baseline and after gastric devascularization, conduit formation, and transposition. The SaO(2) and BVF readings were correlated to clinical outcomes.

RESULTS

The OFS measurements were obtained in 23 patients during esophagectomy, four of whom previously underwent gastric ischemic conditioning. Eight patients developed anastomotic complications. Compared with baseline, conduit creation produced a 29.4% reduction in SaO(2) (p < 0.01), while BVF increased by 28% (p = 0.06). Patients with subsequent anastomotic complications demonstrated a 52.5% decrease in SaO(2) upon conduit creation compared with 15.1% in patients without complications (p = 0.01). Patients who underwent ischemic conditioning did not develop significant changes in SaO(2) (p = 0.72) or BVF (p = 0.5) upon gastric conduit creation.

CONCLUSIONS

Intraoperative OFS demonstrates significant alterations in gastric conduit oxygenation during esophageal replacement, which may be tempered by gastric ischemic conditioning. The degree of intraoperative gastric ischemia resulting from gastric conduit creation is associated with the development of anastomotic complications, suggesting that OFS is useful for assessing changes in conduit oxygenation during esophagectomy. Further studies are needed to refine this technology and investigate the clinical utility of intraoperative conduit oxygenation data.

Gut oxygenation and oxidative damage during and after laparoscopic and open left-sided colon resection: a prospective, randomized, controlled clinical trial

BACKGROUND

Pneumoperitoneum (PP), established for laparoscopic (LPS) operation, has been associated with potential detrimental effects, such as mesenteric ischemia-reperfusion injury. The objective of the trial was to measure intestinal tissue oxygen pressure (PtiO2) and oxidative damage during laparoscopic (LPS) and open colon surgery and during the postoperative course.

METHODS

Forty patients candidate to left-sided colectomy were randomized to undergo open or LPS resection (20 patients/group). During the operation, PtiO2 was measured at established changes of PP pressure (from 0-15 mmHg) and for 6 days postoperatively. PtiO2 was determined by a polarographic microprobe implanted in the colon wall. Ischemia-reperfusion injury was assessed by plasma malondialdehyde (MDA). ClinicalTrial.gov registration number: NCT01040013.

RESULTS

LPS was associated with a higher PtiO2 at the beginning of surgery (73.9±9.4 vs. 64.3±6.4 in open; P=0.04) and at the end of the operation (57.7±7.9 vs. 53.1±4.7 in open; P=0.03). PtiO2 decreased significantly during mesentery traction vs. beginning in both groups (respectively 58.7±13.2 vs. 73.9±9.4 in LPS and 55.3±6.4 vs. 64.3±6.4 in open group; minimum P=0.02). During LPS, there was a significant decrease of PtiO2 only when PP was increased to 15 mmHg (63.2±7.5 vs. 76.6±10.7 at 10 mmHg; P=0.03). PtiO2 also was significantly better in the LPS group during the first 3 days after operation (minimum P=0.04 vs. open). MDA significantly increased in both groups after mesentery traction and at the end of operation vs. baseline levels with no difference between techniques.

CONCLUSIONS

LPS seems to be associated with a better intra- and postoperative PtiO2. High-pressure PP may impair PtiO2.