Effects of circular myotomy on the healing of esophageal suture anastomosis: an experimental study

Critical Role of Pleural Wrap and Post-operative Neonatal Protocol in Long-gap Oesophageal Atresia: A Team Effort

BACKGROUND

The objectives of this study were to bring out the results of application of pleural wrap in primary repair of tracheo - esophageal fistula (TEF) with long-gap oesophageal atresia (LGEA) and also define the role of neonatologists and paediatric intensivists in post-operative management in these patients by laying down standard neonatal management protocol.

MATERIALS AND METHODS

This was a retrospective descriptive observational study conducted between March 2011 and April 2019 on 23 cases of LGEA with TEF. The study was conducted at two tertiary care paediatric surgery centres in Northern part of India wherein these newborn babies were operated by two paediatric surgeons with variable experience of 8-12 years. It also describes the neonatal management protocol used in post-operative period.

RESULTS

Out of 23 patients, 15 were boys and 8 were girls, with a mean age of 32.25 weeks and a mean birth weight of 2.02 kg. The mean hospital stay was 23.5 ± 8 days. Eleven cases had gap between 3 and 3.5 cm, 8 cases between 3.5 and 4 cm and 4 cases had gap more than 4 cm. The incidence of associated anomalies was 52%. Anastomotic leak rate was 8.69%, and 3 (13.04%) patients died in the post-operative period. All the operated patients were managed postoperatively as per strict neonatal management protocol exclusively by the team of neonatologists and neonatal intensivists.

CONCLUSION

Application of pleural wrap over anastomosis following primary repair of LGEA with TEF significantly reduced the incidence of anastomotic leak in our study. Apart from the pleural wrap, the key to successful outcome also is contributed by the little prolonged, controlled ventilation and patience and perseverance in post-operative feeds. This post-operative management protocol that has been followed by us in our study is easily reproducible and can be adopted by paediatric surgeons working alongside neonatologists as a team.

A new method of primary engineering of esophagus using orthotopic in-body tissue architecture

PURPOSE

Tissue engineering of esophagus is required for management of long-gap esophageal atresia (LGEA). Collagenous connective tissue membranes fabricated by in-body tissue architecture (iBTA), called biosheets, can repair esophageal defects and generate tissues similar to native esophagus. However, iBTA requires second-stage surgery because of heterotopic preparation of biosheets. Our aim was to develop orthotopic iBTA for primary engineering of the esophagus by interposing a tubular mold to the esophageal defect.

METHOD

The cervical esophagus of six rats was transected. An acrylic tube (internal diameter 2.6 mm, length 7.0 mm) was inserted and fixed between the ends of the upper and lower esophagus, and a 3 mm-long esophageal defect was created. Four weeks later, the rats were sacrificed for histological analysis.

RESULTS

Postoperatively the rats could intake liquid food. After four weeks, the esophageal defects were filled with regenerated tissues. Histologically the new esophageal walls stained positive for collagen type I. The inner surfaces were covered with stratified squamous epithelium that expressed pan-cytokeratin. In only one of six rats, regeneration of muscular-like tissue was suggested by positive immunohistochemical staining for desmin.

CONCLUSION

Orthotopic iBTA can regenerate a substitute esophagus with esophageal epithelium and collagenous wall. This technique may be a novel treatment for esophageal atresia with gaps of various lengths including LGEA.

A new esophageal elongation technique for long-gap esophageal atresia: in vitro comparison of myotomy techniques

BACKGROUND

Complications such as stricture, leakage, recurrent tracheoesophageal fistula and mucosal pouch are commonly seen in myotomy techniques used for long-gap esophageal atresia (LGEA) treatments. Therefore, we think that there is a clear need for other techniques which would enable us to create more robust and longer esophagus in such cases. In this study, we reviewed multiple V-myotomy (VM) technique and the differences of the said technique with Livaditis circular myotomy (LM) and Kimura spiral myotomy (KM) techniques using literature as an aid.

METHODS

21 esophagus samples from 21 male lambs aged 12 months were used in vitro for the study. All esophageal samples were matched to have a length of 120 mm. Samples were divided into 3 groups of 7 and VM, LM and KM techniques were used in each group, respectively. Post-op esophagus lengths, elongation amount with each incision and perforation pressures were measured.

RESULTS

Post-op esophageal lengths were measured as 227, 210 and 200 mm for VM, LM and KM, respectively. Elongation amount per incision was measured as 5.1, 4 and 3.34 mm, again in previous order of VM, LM, and KM. Finally, perforation pressure following VM, LM, and KM was measured as 460, 400, and 410 mmHg.

CONCLUSION

VM was found to significantly increase total esophagus length and elongation per incision over LM and KM. In addition, VM was also shown to have a higher perforation pressure. Although in vivo live animal studies are required, we can say that VM can be used to create longer and robust esophagus.

Isolation of esophageal stem cells with potential for therapy

PURPOSE

Long-gap esophageal atresia represents a significant challenge for pediatric surgeons and current surgical approaches are associated with significant morbidity. A tissue-engineered esophagus, comprising cells seeded onto a scaffold, represents a therapeutic alternative. In this study, we aimed to determine the optimal techniques for isolation and culture of mouse esophageal epithelial cells and to isolate CD34-positive esophageal epithelial stem cells from cadaveric mouse specimens.

METHODS

Primary epithelial cells were isolated from mouse esophagi by enzymatic dissociation from the mucosal layer (Dispase, Trypsin/EDTA) using three different protocols. In protocol A, isolated mucosa was minced and incubated with trypsin once. In protocol B, intact mucosal sheets underwent two trypsin incubations yielding a single-cell suspension. In protocol C, intact mucosa explants were plated epithelial side down. Epithelial cells were cultured on collagen-coated wells.

RESULTS

Initial findings showed that Protocol B gave the best results in terms of yield, viability, and least contamination with different cell types and microbes. Esophageal epithelial cells isolated using Protocol B were stained for CD34 and sorted using fluorescence-activated cell sorting (FACS). Of the total cells sorted, 8.3% (2-11.3) [%median (range)] were CD34 positive.

CONCLUSIONS

Our results demonstrate that mouse esophageal epithelial cells can be successfully isolated from fresh mouse esophagi using two consecutive trypsin incubations of intact mucosal sheets. Furthermore, the cells obtained using this method were successfully stained for CD34, a putative esophageal epithelial stem cell marker. Further research into the factors necessary for the successful proliferation of CD34 positive stem cell lines is needed to progress toward clinical application.

Repair of long-gap esophageal atresia: gastric conduits may improve outcome—a 20-year single center experience

INTRODUCTION

Treatment of long-gap esophageal atresia (LEA) is a major challenge. Options for reconstruction include native esophagus, or replacement with stomach, colon, or small intestine. However, debate continues regarding the optimal conduit for esophageal replacement.

METHODS

Medical records of patients with a diagnosis of esophageal atresia during a 20-year period were reviewed.

RESULTS

Twenty-eight cases of LEA were identified. Ten patients underwent primary anastomosis either after serial pouch dilations (9/10) and/or after a lengthening procedure (2/10). Nine received colonic interpositions, and the remainder were reconstructed with a gastric tube (n = 3), or gastric interposition (n = 2). One patient died prior to repair, and two await definitive treatment. Repeat esophageal reconstruction was required in four patients because of conduit ischemia. Two ischemic events occurred in the colonic interposition group, and two in the native esophageal repairs. All patients, except one who relocated, received long-term follow-up (mean 4.2 years: range 0.5-11.5 years).

CONCLUSIONS

Surgeon's expertise and patient's anatomy should be considered when selecting an appropriate operation for LEA. Although native esophagus is generally preferred, it is associated with a high rate of stricture. Although our study has a limited by numbers, we found that patients with gastric conduits had lower complication rates and no conduit ischemia. We suggest that gastric transposition may be favored as an initial reconstructive option.

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.

An exclusively intraabdominal distal esophageal segment prevents primary delayed anastomosis in children with pure esophageal atresia

PURPOSE

The aim of this study was to evaluate the outcome of children with pure esophageal atresia (EA) managed by the strategy of delayed primary anastomosis and to find parameters to identify which of these children will have satisfactory esophageal growth to permit a successful primary esophageal anastomosis.

METHODS

Sixteen children with pure EA were treated by delayed anastomosis strategy from June 1992 to May 2001 at the Instituto da Criança-University of São Paulo Medical School. The treatment consisted of creating an early feeding gastrostomy, continuous upper pouch suction, and periodic radiologic/endoscopic assessments of the gap between the superior and inferior esophageal pouches. The first assessment was done 4 weeks after the initial gastrostomy. Subsequent assessments were done, when necessary, 4 to 10 weeks after the first one. Children with the gap between the pouches corresponding to 2 vertebral bodies or less were considered for primary repair.

RESULTS

The waiting period ranged from 8 to 14 weeks. Five children were considered for primary repair (31.3%). All of them had an end-to-end esophageal anastomosis performed without tension. Eleven children (68.7%) did not show significant esophageal growth after the waiting period and were not considered for primary esophageal anastomosis. Eight of them (50%) showed an entirely intraabdominal distal pouch at the first assessment.

CONCLUSIONS

(1) Infants with an exclusively intraabdominal distal pouch at the first evaluation will not reach sufficient elongation of the pouches and should be considered early as a candidate for esophageal replacement. (2) Combined radiologic/endoscopic assessment and the measurement of the gap in terms of vertebral bodies is a practical and reliable method to predict the feasibility of primary anastomosis. (3) Using these criteria, primary anastomosis could be accomplished in less than a third of cases.

Significance of the clinical course and early upper gastrointestinal studies in predicting complications associated with repair of esophageal atresia

BACKGROUND/PURPOSE

In many centers, use of upper gastrointestinal (UGI) contrast studies in the early postoperative period after esophageal atresia (EA) repair is considered routine. Indications for this are many, including searching for existing problems and predicting future complications. However, most major complications, both early and late, usually are identified clinically before any radiologic studies. The purpose of this study was to investigate factors that may anticipate the development of postoperative complications after EA repair, looking particularly at the predictive value of routine early postoperative UGI studies.

METHODS

A total of 111 consecutive cases of EA were identified retrospectively over a 10-year period from 2 major Canadian pediatric health centers. One hundred one were associated with a distal tracheoesophageal fistula (TEF), of which, 90 had repairs. Ninety-seven percent of these had a UGI study at a median of 9.1 postoperative days (range, 2 to 23) before consideration of oral feeding. Charts were reviewed looking at patient variables, surgical factors, early UGI findings, and postoperative courses. Complications that required intervention were noted, including anastomotic leaks, gastroesophageal reflux (GER), strictures, and recurrent and missed fistulae. All initial UGI studies were reexamined by 1 of 2 pediatric radiologists. Logistic regression was used to examine relationships between these clinical and radiologic variables and outcomes.

RESULTS

Of the variables analyzed, univariate analysis showed clinically significant leaks to be associated with intraoperative factors (subjective degree of anastomotic tension, and the use of myotomies) and early postoperative clinical evidence suggesting a leak. In a multivariate model, all remained independently significant except for the use of myotomies. Later development of clinically significant GER also was associated with the degree of tension. It had no relationship, however, with findings of dysmotility, esophageal shortening, or reflux at the initial UGI study. Development of a stricture requiring dilatations or resection was associated with a history of clinically evident GER only; no relationships were seen with a history of an anastomotic leak or any other clinical, operative, or radiographic variables. Missed or recurrent fistulae were all suspected clinically before radiologic confirmation.

CONCLUSIONS

Early and late complications after repair of EA can be identified and potentially anticipated based on clinical findings at the time of repair and during the postoperative period. The use of early "routine" UGI studies, with no suspicion of a problem, has little value in terms of predicting complications or future clinical course.