Functional capillary density in ischemic conditioning: implications for esophageal resection with the gastric conduit

Pilot Trial on Ischemic Conditioning of the Gastric Conduit in Esophageal Cancer: Feasibility and Impact on Anastomotic Leakage (TIGOAL-I)

Objective

To evaluate the feasibility, safety, and effectiveness of gastric conditioning using preoperative arterial embolization (PAE) before McKeown esophagectomy at a tertiary university hospital.

Background

Cervical anastomotic leakage (AL) is a common complication of esophagectomy. Limited clinical evidence suggests that gastric conditioning mitigates this risk.

Methods

This pilot randomized clinical trial was conducted between April 2016 and October 2021 at a single-center tertiary hospital. Eligible patients with resectable malignant esophageal tumors, suitable for cervical esophagogastrostomy, were randomized into 2 groups: one receiving PAE and the other standard treatment. The primary endpoints were PAE-related complications and incidence of cervical AL.

Results

The study enrolled 40 eligible patients. PAE-related morbidity was 10%, with no Clavien-Dindo grade III complications. Cervical AL rates were similar between the groups (35% vs 25%, P = 0.49), even when conduit necrosis was included (35% vs 35%, P = 1). However, AL severity, including conduit necrosis, was higher in the control group according to the Clavien-Dindo ≥IIIb (5% vs 30%, P = 0.029) and Comprehensive Complication Index (20.9 vs 33.7, P = 0.01). No significant differences were found in other postoperative complications, such as pneumonia or postoperative mortality.

Conclusions

PAE is a feasible and safe method for gastric conditioning before McKeown minimally invasive esophagectomy and shows promise for preventing severe AL. However, further studies are required to confirm its efficacy.

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.

Bladder augmentation from an insider's perspective: a review of the literature on microcirculatory studies

Augmentation cystoplasty is an exemplary multiorgan intervention in urology which is particularly associated with microvascular damage. Our aim was to review the available intravital imaging techniques and data obtained from clinical and experimental microcirculatory studies involving the most important donor organs applied in bladder augmentation. Although numerous direct or indirect methods are available to assess the condition of microvessels the implementation of microcirculatory diagnostic methods in humans is still challenging and the assessment of organ microcirculation in the operating theatre has limitations. Nevertheless, preclinical studies generally report good internal validity and although prospective human protocols with reduced variability are needed, a possible positive impact of microcirculatory diagnostics on the clinical outcomes of urologic surgery can be anticipated.

Ischaemic conditioning of the stomach previous to esophageal surgery

A gastric conduit is most frequently used for reconstruction in oesophageal surgery, and ischemia of the conduit is the most fragile aspect of the esophagogastric anastomosis with as consequence the anastomotic leakage. In order to avoid it, the concept of ischaemic conditioning of the stomach previous to surgery has been designed. The basis of ischemic conditioning is that interrupting vascularization of the stomach before making the anastomosis eases the gastric fundus adaptation to ischemic conditions. It consists of the interruption of the principal feeding arteries of the stomach (except the right gastroepiploic artery) weeks before esophagectomy. Previously published literature contemplates two different techniques: angiographic embolization or laparoscopic ligation or division of vessels. In this study, the anatomic and physio-pathologic background of ischemic preconditioning is described and the published current evidence is reviewed.

Case report: Gastric tube cancer after esophagectomy-Retrograde perfusion after proximal resection of right gastroepiploic artery

INTRODUCTION

We report a case of a 57-year-old patient with gastric tube cancer after subtotal esophagectomy and retrosternal gastric pull up.

CASE PRESENTATION

The patient developed gastric cancer 4 years after undergoing treatment for esophageal squamous cell cancer; the treatments included thoracoscopic subtotal esophagectomy, gastric pull-up reconstruction via a retrosternal route in salvage setting following definitive chemoradiation. Because the gastric tube cancer was located around the pylorus, transabdominal partial resection, which is much less invasive than total resection via sternotomy, was performed. During surgery, retrograde pulsation of the proximally resected right gastroepiploic artery was observed. Owing to an ample blood supply to the oral remnant of the gastric tube, vascular reconstruction of the right gastroepiploic artery was omitted. The postoperative recovery was eventless.

DISCUSSION

The right gastroepiploic artery is considered essential for blood supply to the gastric tube. However, there was no sign of ischemia after proximal resection of this artery, which suggests the vasculature was altered after gastric tube construction.

CONCLUSION

This case shows that partial distal resection of the gastric tube can be performed safely without vascular reconstruction of the right gastroepiploic artery. Favorable long-term results after gastric tube reconstruction support the possibility of bilateral blood supply to the gastroepiploic arcade.

Neovascularization after ischemic conditioning of the stomach and the influence of follow-up neoadjuvant chemotherapy thereon

Introduction

Esophagectomy and reconstruction remain the optimal treatment for patients with resectable esophageal cancer. Neovascularization after ischemic conditioning of the stomach before esophagectomy is a laparoscopic procedure which may potentially reduce gastric conduit ischemia.

Aim

To investigate the influence of ischemic conditioning on neovascularization along the greater curvature of the stomach and to explore the effect of neoadjuvant chemotherapy on neovascularization after ischemic conditioning.

Material and methods

Staging laparoscopy was performed before the main resection procedure; during this procedure ischemic conditioning was performed. Samples taken from the human stomach were divided into 3 groups: group A – patients after ischemic conditioning with a delay of 30–45 days after left gastric artery (LGA) ligation (n = 4); group B – patients who were undergoing neoadjuvant chemotherapy with a delay of 90–140 days after left gastric artery ligation (n = 4); and control group C – patients without ischemic conditioning (n = 7).

Results

After ischemic conditioning with a delay of 30–45 days, the count of neovessels along the greater curvature of the stomach increased from 5.4 ±0.7 in the control group to 17.5 ±0.9 in a low-power field of view (LPF) in group A and increased still further on average to 19.8 ±10.4 in group B.

Conclusions

Left gastric artery ligation only is a sufficient procedure for ischemic conditioning of the stomach. Neovascularization along the greater curvature is a continuous process that depends on delay time. Neoadjuvant therapy has no influence on the effect of neovascularization.

Comparison of cervical anastomotic leak and stenosis after oesophagectomy for carcinoma according to the interval of the stomach ischaemic conditioning

Background Stomach preparation by ischaemic conditioning prior to oesophageal resection represents a potential method of reducing the risk of anastomotic complications. This study compares the results of the anastomotic complications of cervical anastomosis after oesophagectomy with a short interval after ischaemic conditioning (group S) and a long interval (group L). Methods Subjects undergoing oesophagectomy for carcinoma after ischaemic conditioning were divided into two groups. Group S had a median interval between ischaemic conditioning and resection of 20 days, while for group L the median interval was 49 days. Anastomotic leak and anastomotic stenosis in relation to the interval between ischaemic conditioning and actual resection were followed. Results After ischaemic conditioning, 33 subjects in total underwent surgery for carcinoma; 19 subjects in group S and 14 subjects in group L. Anastomotic leak incidence was comparable in both groups. Anastomotic stenosis occurred in 21% of cases in group S and 7% of cases in group L (not statistically significant). Conclusions A long interval between ischaemic conditioning and oesophagectomy does not adversely affect the postoperative complications. A lower incidence of anastomosis stenoses was found in subjects with a longer interval, however, given the size of our sample, the statistical significance was not demonstrated. Both groups seem comparable in surgical procedure course and postoperative complications.

Laparoscopic ischemic conditioning of the stomach increases neovascularization of the gastric conduit in patients undergoing esophagectomy for cancer

BACKGROUND AND OBJECTIVES

Gastric ischemic preconditioning has been proposed to improve blood flow and reduce the incidence of anastomotic complications following esophagectomy with gastric pull-up. This study aimed to evaluate the effect of prolonged ischemic preconditioning on the degree of neovascularization in the distal gastric conduit at the time of esophagectomy.

METHODS

A retrospective review of a prospectively maintained database identified 30 patients who underwent esophagectomy. The patients were divided into three groups: control (no preconditioning, n = 9), partial (short gastric vessel ligation only, n = 8), and complete ischemic preconditioning (left and short gastric vessel ligation, n = 13). Microvessel counts were assessed, using immunohistologic analysis to determine the degree of neovascularization at the distal gastric margin.

RESULTS

The groups did not differ in age, gender, BMI, pathologic stage, or cancer subtype. Ischemic preconditioning durations were 163 ± 156 days for partial ischemic preconditioning, compared to 95 ± 50 days for complete ischemic preconditioning (P = 0.2). Immunohistologic analysis demonstrated an increase in microvessel counts of 29% following partial ischemic preconditioning (P = 0.3) and 67% after complete ischemic preconditioning (P < 0.0001), compared to controls.

CONCLUSIONS

Our study indicates that prolonged ischemic preconditioning is safe and does not interfere with subsequent esophagectomy. Complete ischemic preconditioning increased neovascularization in the distal gastric conduit.

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.

Ischemic Conditioning of the Stomach in the Prevention of Esophagogastric Anastomotic Leakage After Esophagectomy

Esophagectomy with esophagogastric anastomosis is a major procedure, and its most feared complication is anastomotic leakage. Ischemic conditioning of the stomach is a method used with the aim of reducing the risk of leakage. It consists of partial gastric devascularization through embolization or laparoscopy followed by esophagectomy and anastomosis at a second stage, thus providing the time for the gastric conduit to adapt to the acute ischemia at the time of its formation. This review analyzes the information from all currently available experimental and clinical studies with the purpose of assessing the current role of the technique and to provide future recommendations.

The novel use of intraoperative laser-induced fluorescence of indocyanine green tissue angiography for evaluation of the gastric conduit in esophageal reconstructive surgery

BACKGROUND

Esophagectomy with reconstruction using a gastric conduit is associated with a relatively high rate of anastomotic leakage. We used indocyanine green tissue angiography to evaluate the gastric conduit intraoperatively before gastroesophageal anastomosis to identify ischemia.

METHODS

We performed an institutional review board-approved retrospective review of all esophagectomies performed from 2010 to the beginning of 2011. Patient histories and perioperative outcomes were reviewed retrospectively. Postoperative morbidity and 30-day mortality were determined.

RESULTS

Eleven patients had an esophagectomy performed using this technology. All had adequate perfusion on gross examination. All but 1 had good perfusion with tissue angiography, and there were 2 anastomotic leakages leaks including this patient. There were no mortalities at 30 days.

CONCLUSIONS

We report preliminary results using this imaging system in esophageal reconstructive surgery. Larger randomized controlled studies are needed to determine if surgical outcomes can be improved using this technology.

Randomized controlled trial of laparoscopic gastric ischemic conditioning prior to minimally invasive esophagectomy, the LOGIC trial

INTRODUCTION

Minimally invasive esophagectomy (MIE) is a viable alternative to open resection for the management of esophagogastric cancer. However, the technique may relate to a higher incidence of ischemia-related gastric conduit complications. Laparoscopic ischemic conditioning (LIC) by ligating the left gastric vessels 2 weeks before MIE may have a protective role, possibly through an improvement of conduit perfusion. This project was designed to evaluate whether LIC influenced ultimate conduit perfusion.

METHODS

A randomized controlled trial was designed to compare MIE with LIC (L) against MIE without (N). The project began in May 2009 and was offered to consecutive patients with the objective of recruiting 22 in each arm. Sample size calculations were based on data from previous clinical series. The main outcome measure was perfusion recorded by validated laser Doppler fluximetry, at the fundus (F) and greater curve (G); performed at routine staging laparoscopy and every stage of an MIE. A perfusion coefficient measured as ratio at stage of MIE over baseline was used for statistical analysis.

RESULTS

Sixteen patients were recruited before an interim analysis of the trial data. At staging laparoscopy perfusion at F was higher than at G (p = 0.016). In the L cohort, an apparent rise in perfusion at G is observed post intervention (p = 0.176). At MIE, baseline perfusion is comparable for both arms; however, a significant drop is observed at both locations once the stomach is mobilized and exteriorized (p = 0.001). Once delivered at the neck, perfusion coefficient is approximately 38% of baseline levels. However, there was no discernible difference between the L (38.3 ± 12) and N (37.7 ± 16.8) cohorts (p = 0.798).

CONCLUSIONS

LIC does not translate into an improved perfusion of the gastric conduit tip. The benefits reported from published clinical series suggest that the resistance of the conduit to ischemia occurs through alternative possibly microcellular mechanisms.

Vascular conditioning of the stomach before esophageal reconstruction by gastric interposition

Gastric interposition with intrathoracic or cervical esophagogastrostomy is currently the preferred operation for reconstruction after esophagectomy. Anastomotic leaks however result from poor vascular supply to the proximal stomach. They are responsible for significant morbidity and mortality. 'Ischemic conditioning' of the interposed stomach has been proposed as a technique where the 'delay phenomenon' aims at improving the microcirculation of the gastric conduit and preventing anastomotic leakage. Experimental observations and clinical studies have been conducted to document the immediate effects and results of this approach. The aim of this work is to review the principles, pathophysiology, experimental, and clinical evidence related to vascular conditioning of the stomach prior to esophagectomy with gastric interposition and esophagogastric anastomosis. MEDLINE and PubMed were searched to identify articles related to vascular conditioning of the stomach. Cross references were added and reviewed to complete the reference list. The anatomic basis of ischemic conditioning, the prevalence of ischemic events on the gastric conduit, the methodology to assess the microcirculation before and after gastric devascularization, animal experiments, and clinical studies reported on this approach were reviewed. Ten experimental works, eleven clinical observations, four reviews, and two editorial commentaries addressing ischemic conditioning of the stomach were identified and reviewed. Experimental observations document improved microcirculation to the proximal stomach following partial gastric devascularization. Clinical reports show the feasibility and relative safety of gastric ischemic conditioning. Preliminary observations suggest potential improvements to the gastric microcirculation resulting from gastric ischemic conditioning. This approach may help prevent complications at the esophagogastric anastomosis. The actual level of evidence however cannot promote its use outside of clinical research protocols.

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.

Delayed esophagogastrostomy: a safe strategy for management of patients with ischemic gastric conduit at time of esophagectomy

BACKGROUND

Ischemia of the gastric conduit remains an important complication of esophagectomy and is associated with an increased risk of anastomotic leak and sepsis. We report a group of patients with multiple comorbid conditions and an ischemic gastric conduit that was successfully managed by a delayed esophagogastrostomy.

STUDY DESIGN

Between 2000 and 2007, esophagectomy with gastric pullup was performed in 554 patients. In 37 patients (7%), the combination of an ischemic graft and substantial comorbid conditions prompted delayed reconstruction to avoid an immediate esophagogastrostomy. In these patients, the gastric conduit was brought up and secured in the neck, and a cervical esophagostomy was constructed. Subsequently, a delayed esophagogastrostomy was performed through neck incision. Outcomes were analyzed at a median of 22 months (interquartile range [IQR], 13 to 30 months).

RESULTS

There were 29 male and 8 female patients, with a median age of 65 years (IQR, 58 to 75 years). Thirty-one patients had malignant disease; 12 received neoadjuvant therapy. All 37 patients recovered from their esophagectomy without evidence of ischemic necrosis or fistula from their gastric conduit. In 35 patients, a delayed esophagogastrostomy was performed at a median of 98 days (IQR, 89 to 110 days). At the time of reconstruction, all had well-perfused gastric conduits, and the anastomoses healed without leak, wound infection, or sepsis. A stricture developed in three patients and was treated with dilation. Delayed esophagogastrostomy was never performed in two patients because of development of recurrent malignant disease.

CONCLUSIONS

Delayed esophagogastrostomy is a safe strategy for management of patients with comorbidities and an ischemic gastric conduit at the time of esophagectomy.