Tubed latissimus dorsi musculocutaneous flaps for thoracic esophageal replacement: an experimental study

Reconstruction of a partial esophageal defect using tunica vaginalis and buccal mucosa autograft: an experimental study in mongrel dogs

In veterinary clinics, esophageal reconstruction is essential in many clinical situations. In this study, two autografts, the tunica vaginalis (TV) and the buccal mucosa (BM), were proposed to reconstruct a semi-circumferential cervical esophageal defect in dogs. This study aimed to verify whether these two grafts could successfully patch esophageal defects. Twelve male mongrel dogs were divided into two groups. Following cervical esophagoplasty, the defective area was patched with either a TV or a BM graft. Comprehensive clinical, serum biochemical, and histological analyses were performed to evaluate the two grafts. Throughout the study (120 days), the dogs survived the procedure well with minor complications. The lumen of the patched areas was covered with mucosa, with slight scar retraction. Compared with that of the natural esophagus, the average relative luminal diameter was not significantly decreased. Importantly, the measured cortisol and inflammatory marker levels returned to the preoperative levels after 14 days. Although histological examination revealed that both grafts repaired the esophageal defect with complete re-epithelialization, the BM graft showed a histological structure similar to that of the natural esophagus. Both grafts effectively repaired the esophageal defect with minor complications; therefore, both are recommended as promising low-cost clinical alternatives for cervical esophagoplasty in dogs.

Surgical techniques for esophageal replacement in children

PURPOSE

Surgical techniques for esophageal replacement (ER) in children include colon interposition, gastric tube, gastric transposition, and jejunal interposition. This review evaluates the merits and demerits of each.

METHOD

Surgical techniques, complications, and outcome of ER are reviewed over last seven decades.

RESULTS

Colon interposition is the time-tested procedure with minimal and less serious complications. Long-term complications include reflux, halitosis, colonic segment dilatation, and anastomotic stricture, sometimes requiring surgical interventions especially for dilatation and reflux. Gastric tube is technically more risky, and associated with early serious complications like prolonged leak in neck or mediastinum, graft necrosis, and ischemia leading to stricture of the tube. Long-term results are good. Gastric transposition is much simpler, can be performed in emergency and in newborns. It involves a single anastomosis in the neck. Post-operative complications include gastric stasis, bile reflux, restricted growth, and decreased pulmonary functional capacity. Jejunal interposition has not been used extensively due to short mesentery but long-term results are good in expert hands.

CONCLUSION

Colon is the most preferred and safest organ for ER. Stomach is a vascular and muscular organ with lower risk of ischemia. Gastric tube is a demanding technique. Jejunum or ileum is alternative for redo cases.

Grafts of porcine intestinal submucosa for repair of cervical and abdominal esophageal defects in the rat

Porcine small intestinal submucosa (SIS) is a cell-free collagen matrix that has demonstrated its ability as scaffold material for constructive remodeling of damaged or missing tissue. The purpose of this study was to evaluate the morphology and function of esophagoplasty in rat using a porcine SIS scaffold for the repair of a semi-circumferential defect in the cervical or in the abdominal esophagus. Sixty-seven rats underwent surgical excision of the anterior wall either of the cervical or of the abdominal esophagus and subsequent repair of the defect with an SIS patch graft. Outcomes of weight gain, signs of dysphagia, hematological and serum chemistry parameters, and barium swallow studies were used to assess the progress of healing and function over a 150-day time period. The grafts were studied for gross changes and histology at predetermined time points. Ninety-four percent of the SIS-treated rats survived, showing no significant differences in survival rate between groups. The grafted animals did well, without signs of dysphagia, and gaining weight. Barium swallow studies showed no evidence of fistula, significant stenosis, or diverticula. No hematological or serum biochemistry abnormalities were found. By 150 days, the SIS graft was replaced with esophageal-derived tissues. Specimens were completely lined by keratinized stratified squamous epithelium and showed complete regeneration of muscle fibers and scarce immunoreactivity for nerve. In the rat model, a patch graft technique using porcine SIS appears to induce esophageal regrowth either in cervical and abdominal esophagus. The repair mechanism occurred through a regenerative healing process.

Esophageal replacement in rat using porcine intestinal submucosa as a patch or a tube-shaped graft

This study compares the efficacy of porcine intestinal submucosa (SIS) patch graft versus SIS-tube graft in esophageal replacement, using a novel esophageal regeneration model. Clinical function, as well as macroscopic and microscopic morphology were evaluated in both SIS-treated groups. We performed semi-circumferential esophageal excision followed by repair of the defect using either a SIS-patch graft (group I) or segmental esophageal excision followed by a SIS-tube interposition graft (group II) in rats. The 28-day survival rate was significantly different between the SIS-treated groups (100% in group I vs. 0% in group II). Unlike the rats in group II, which died within the first postoperative month due to esophageal dysfunction, all surviving animals in group I resumed a normal solid diet within a few days after surgery, without signs of esophageal dysfunction and gained weight. Barium swallow studies showed no evidence of fistula, significant stenosis or diverticula. No hematological or serum biochemistry abnormalities were found. By day 150 the SIS patch was replaced by esophageal-derived tissues. In the rat model, a patch graft technique using SIS appeared to induce esophageal regrowth and provided an initial and long-term satisfactory function, while a tube-shaped graft technique using SIS was unsuccessful.

Emprego de enxerto biológico na reconstrução de ferida experimental no esôfago cervical de ovinos

Dezoito ovelhas foram divididas em dois grupos (I e II) de nove animais, e cada grupo dividido em dois subgrupos (Ia, Ib e IIa, IIb) conforme o tempo de avaliação, de 45 dias para os subgrupos a e de 60 dias para os subgrupos b. Todos os animais tiveram um segmento esofágico retangular de 2,5×1,5cm removido. Os animais do grupo I receberam enxerto de aorta canina, enquanto os do grupo II receberam enxerto de fáscia lata canina. Todos os enxertos foram previamente conservados entre 30 e 90 dias em glicerina 98%. A integração dos enxertos foi avaliada por meio de exame clínico (inspeção da ferida cirúrgica, comportamento quanto ao apetite e sede, capacidade de deglutição e regurgitação), hemograma completo, esofagograma contrastado e análises macroscópica e histopatológica. Concluiu-se que os tecidos enxertados foram suficientes para suportar a pressão da passagem do alimento e para a vedação esofágica, oferecendo condições para a regeneração epitelial.

Tubed latissimus dorsi musculocutaneous flaps for esophageal replacement in puppies: long-term follow-up

PURPOSE

The aim of this study was to show that a tubed latissimus dorsi musculocutaneous flap (tubed LDMCF) may be useful for treating circumferential esophageal defects.

METHODS

A segment of esophagus 3 vertebrae long was excised through a right thoracotomy in each of 6 puppies, and a tubed LDMCF was interposed between the cut ends of esophagus. The puppies were sacrificed after a mean follow-up period of 6.6 years. The tubed LDMCF was examined histologically. Functional integrity was assessed using barium meal and endoscopy before sacrifice.

RESULTS

All puppies survived and grew normally on a normal diet, although 4 vomited occasionally. There was smooth passage of barium through the tubed LDMCF without stenosis, although endoscopy showed regrowth of hair. Histologically, no metaplasia, dysplasia, or malignancy was observed in any tubed LDMCF.

CONCLUSIONS

The tubed LDMCF is technically safe, obviates the necessity for laparotomy, and long-term follow-up would suggest that it is histologically stable. Thus, it could become an alternative procedure for bridging esophageal defects.