64Cu-ATSM Hypoxia Positron Emission Tomography for Detection of Conduit Ischemia in an Experimental Rat Esophagectomy Model. PLoS One. 2015;10:e0131083. [PMID: 26098420 PMCID: PMC4476727 DOI: 10.1371/journal.pone.0131083]

Laparoscopic ischaemic conditioning of the gastric conduit prior to a hybrid mckeown oesophagectomy may not decrease the risk of anastomotic leak

Introduction

Morbidity associated with anastomotic leak after oesophagectomy is significant. Techniques to reduce this risk include ischaemic conditioning of the gastric conduit prior to oesophagectomy.

Aim

To quantify the rate of anastomotic leak after a hybrid minimally invasive McKeown oesophagectomy preceded by laparoscopic gastric devascularization (LGD).

Material and methods

We identified patients who had undergone neoadjuvant chemoradiotherapy followed by LGD and McKeown oesophagectomy and conducted a retrospective case series. The primary outcome was anastomotic leak, and secondary outcomes included common post-operative complications within 30 days.

Results

Eleven patients were identified. Seventy-three per cent were male, and 7 of 11 patients were age 70+ years. 91% of tumours were located in the lower oesophagus or gastroesophageal junction (GEJ), and 72% of the series had clinical stage of II–III. The median ischaemic conditioning time was 15 days. Eighteen per cent of patients developed an anastomotic leak, and all were managed non-operatively. One patient developed an anastomotic stricture. Three patients developed pneumonia. Three patients suffered wound infection at the site of the neck incision. One had respiratory failure requiring ventilator support. None required reoperation or readmission. There were no mortalities following either operation.

Conclusions

Laparoscopic ischaemic conditioning via LGD prior to a hybrid McKeown oesophagectomy for malignancy was associated with a leak rate similar to previously published data for a McKeown oesophagectomy without prior LGD.

Cellular Uptake of the ATSM-Cu(II) Complex under Hypoxic Conditions

The Cu(II)-diacetyl-bis (N4-methylthiosemicarbazone) complex (ATSM-Cu(II)) has been suggested as a promising positron emission tomography (PET) agent for hypoxia imaging. Several in-vivo studies have shown its potential to detect hypoxic tumors. However, its uptake mechanism and its specificity to various cancer cell lines have been less studied. Herein, we tested ATSM-Cu(II) toxicity, uptake, and reduction, using four different cell types: (1) mouse breast cancer cells (DA-3), (2) human embryonic kidney cells (HEK-293), (3) breast cancer cells (MCF-7), and (4) cervical cancer cells (Hela) under normoxic and hypoxic conditions. We showed that ATSM-Cu(II) is toxic to breast cancer cells under normoxic and hypoxic conditions; however, it is not toxic to normal HEK-293 non-cancer cells. We showed that the Cu(I) content in breast cancer cell after treatment with ATSM-Cu(II) under hypoxic conditions is higher than in normal cells, despite that the uptake of ATSM-Cu(II) is a bit higher in normal cells than in breast cancer cells. This study suggests that the redox potential of ATSM-Cu(II) is higher in breast cancer cells than in normal cells; thus, its toxicity to cancer cells is increased.

Using simple interrupted suture anastomoses may impair translatability of experimental rodent oesophageal surgery

Background/purpose: Irreproducibility and missing translatability are major drawbacks in experimental animal studies. Hand-sewn anastomoses in oesophageal surgery are usually continuous, whereas those in experimental oesophageal surgery are widely performed using the simple interrupted technique. It has been implicated to be inferior in tolerating anastomotic tension, which we aimed to test in rats due to their importance as an animal model in oesophageal surgery.Methods: We determined linear breaking strengths for the native oesophagus (n = 10), the simple interrupted suture anastomosis (n = 11), and the simple stitch (n = 9) in 8-week old Sprague-Dawley rats. Experiments were powered to a margin of error of 10% around the results of exploratory investigations. The comparison of anastomotic resilience between native organ and simple interrupted suture anastomosis was a priori powered to 99%.Results: Native oesophagi sustained traction forces of 4.25 N (95% CI: 4.03-4.58 N), but the simple interrupted suture anastomosis had only 38.6% (Δ= -2.78 N, 95% CI: -2.46 to -3.11 N, p < .0001) of the resilience of native oesophagi.Conclusions: Oesophageal division and re-anastomosis markedly decreases resilience to traction forces compared to the native organ. This effect is even more pronounced in rats compared to other species and might impair transferability of results.

Early detection of complications: anastomotic leakage

Anastomotic leakage (AL) is one of the most critical and detrimental complications in esophageal surgery. Early diagnosis and timely therapeutic action are necessary if patients are to avoid AL-related problems. However, there is no gold standard or consensus for early diagnosis. In this review, we focus on summarizing the definition and types of AL and modalities for early diagnosis of AL after esophagectomy.

Assessment of graft perfusion and oxygenation for improved outcome in esophageal cancer surgery: Protocol for a single-center prospective observational study

INTRODUCTION

The main cause of anastomotic leakage (AL) is tissue hypoxia, which results from impaired perfusion of the pedicle stomach graft after esophageal reconstruction. Clinical judgment is unreliable in determining graft perfusion. Therefore, an objective, validated, and reproducible method is urgently needed. Near infrared fluorescence perfusion imaging using indocyanine green (ICG) is an emerging and promising modality. This study's objectives are to evaluate the feasibility of quantification of ICG angiography (ICGA) to assess graft perfusion and to validate ICGA by comparison with hemodynamic parameters, blood and tissue expression of hypoxia-induced markers, and tissue mitochondrial respiration rates. And, second, to evaluate its ability to predict AL in patients after minimally invasive esophagectomy (MIE).

METHODS

Patients (N = 70) with resectable esophageal cancer will be recruited for standard MIE. ICGA will be performed after graft creation and thoracic pull-up. Dynamic digital images will be obtained starting after intravenous bolus administration of ICG. The resulting images will be subjected to curve analysis and to compartmental analysis based on the adiabatic approximation to tissue homogeneity kinetic model. The calculated perfusion parameters will be compared to intraoperative hemodynamic data to evaluate the effects of patient hemodynamics. To verify whether graft perfusion represents tissue oxygenation, ICGA perfusion parameters will be compared with systemic and serosa lactate from the stomach graft. In addition, perfusion parameters will be compared to tissue expression of hypoxia-related markers and mitochondrial chain respiratory rate. Finally, the ability of functional, histological, and cellular perfusion and oxygenation parameters to predict AL and postoperative morbidity in general will be evaluated using the appropriate univariate and multivariate statistical analyses.

DISCUSSION

The results of this project may lead to a novel, reproducible, and minimally invasive method to objectively assess perioperative anastomotic perfusion during MIE, potentially reducing the incidence of AL and its associated severe morbidity and mortality.

TRIAL REGISTRATION

Clinicaltrials.gov registration number is NCT03587532. The study was approved by the ethical committee of the Ghent University, Belgium (B670201836427).

Esophagogastric anastomosis in rats: Improved healing by BPC 157 and L-arginine, aggravated by L-NAME

AIM

To cure typically life-threatening esophagogastric anastomosis in rats, lacking anastomosis healing and sphincter function rescue, in particular.

METHODS

Because we assume esophagogastric fistulas represent a particular NO-system disability, we attempt to identify the benefits of anti-ulcer stable gastric pentadecapeptide BPC 157, which was in trials for ulcerative colitis and currently for multiple sclerosis, in rats with esophagocutaneous fistulas. Previously, BPC 157 therapies have promoted the healing of intestinal anastomosis and fistulas, and esophagitis and gastric lesions, along with rescued sphincter function. Additionally, BPC 157 particularly interacts with the NO-system. In the 4 d after esophagogastric anastomosis creation, rats received medication (/kg intraperitoneally once daily: BPC 157 (10 μg, 10 ng), L-NAME (5 mg), or L-arginine (100 mg) alone and/or combined or BPC 157 (10 μg, 10 ng) in drinking water). For rats underwent esophagogastric anastomosis, daily assessment included progressive stomach damage (sum of the longest diameters, mm), esophagitis (scored 0-5), weak anastomosis (mL H₂O before leak), low pressure in esophagus at anastomosis and in the pyloric sphincter (cm H₂O), progressive weight loss (g) and mortality. Immediate effect assessed blood vessels disappearance (scored 0-5) at the stomach surface immediately after anastomosis creation.

RESULTS

BPC 157 (all regimens) fully counteracted the perilous disease course from the very beginning (i.e., with the BPC 157 bath, blood vessels remained present at the gastric surface after anastomosis creation) and eliminated mortality. Additionally, BPC 157 treatment in combination with L-NAME nullified any effect of L-NAME that otherwise intensified the regular course. Consistently, with worsening (with L-NAME administration) and amelioration (with L-arginine), either L-arginine amelioration prevails (attenuated esophageal and gastric lesions) or they counteract each other (L-NAME + L-arginine); with the addition of BPC 157 (L-NAME + L-arginine + BPC 157), there was a marked beneficial effect. BPC 157 treatment for esophagogastric anastomosis, along with NOS-blocker L-NAME and/or NOS substrate L-arginine, demonstrated an innate NO-system disability (as observed with L-arginine effectiveness). BPC 157 distinctively affected corresponding events: worsening (obtained with L-NAME administration that was counteracted); or amelioration (L-arginine + BPC 157-rats correspond to BPC 157-rats).

CONCLUSION

Innate NO-system disability for esophagogastric anastomoses, including L-NAME-worsening, suggests that these effects could be corrected by L-arginine and almost completely eliminated by BPC 157 therapy.