الفهرس 
ESOPHAGEAL ATRESIAOnly 14 pages are availabe for public view
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Abstract
Various maneuvers have been described to overcome long gap esophageal atresia. It is well documented that during the first several months of life, the gap between the two ends of the esophagus tends to lessen because of spontaneous growth, which makes primary repair more feasible. As the infant grows, the blind esophageal segments grow and elongate. The process of esophageal elongationcan be monitored by imaging studies that use contrastmaterial, metallic probes, or bougies placed in the upperand lower esophageal segments.In addition, many preoperative mechanical techniques have been described as a means to facilitate narrowing of the esophageal gap. In 1965, Howard and Myers described upper pouch bougienage. In this technique, a bougie is passed through the mouth into the upper pouch, with forward pressure applied once or twice daily. Primary anastomosis is done when the esophageal pouches become close together. The use of preoperative upper and lower pouch bougienage to decrease gap length has also been described. Vogel et al used hydrostaticpressure to stimulate distal esophageal pouch growth. In 1975, Hendren and Hale reported using an electromagnetic field to pull together metallic ”bullets” placed in the two ends of the esophagus in order to shorten the gap. Oehlerking et al have designed a device that builds upon the use of internal permanent magnets to stretch the proximal and distal esophageal pouches together until anastomosis occurs. It can hydraulically actuate a magnet stack so as to control the distance between two sets of permanent magnets independent of the esophageal gap size maintaining a constant desired force between the esophageal pouches during the stretching process, reducing the risk of injury to the delicate esophageal tissue by excessive magnetic force.
Various innovative operative techniques designed to narrow the long gap before attempted surgical esophageal anastomosis have been advocated.In 1971, Rehbein and Schweder bridged the gap by introducing a silver prosthesis, to which both segments were attached. A fibrous canal developped around such a prosthesis which was dilated by repeated bouginage. Also they described the use of a perlon thread bridging the gap between the two ends of the esophagus which were approximated as far as possible by three sutures. Four weeks later, using the perlon thread, a silver olive was introduced within each lumen.The olives were pushed toward each other until the two ends of the esophagus were pressed together and a fistula was created. A canal may form around the perlon thread before introducing the metal olives. Shafer and David created a fistula between the two ends of the esophagus by connecting the two ends of the mobilized esophagus with a bridging silk suture. Most of the time, spontaneous fistulization will occur. If it doesn’t occur (the 2 esophageal ends are together but without communication), a fistula is created under fluoroscopy. Another method that facilitates esophageal lengthening is a multistaged extrathoracic elongation technique in which the upper part of the esophagus is mobilized and initially brought out as an end cervical esophagostomy. Every 2 to 3 months, the esophagus and its cutaneous stoma are surgically mobilized and translocated down the anterior chest wall until enough length is achieved to perform an end-to-end esophageal anastomosis. More recently, Foker has described a novel technique in which traction sutures on both the proximal and distal esophageal pouches exit through the chest wall and are serially pulled in opposite directions until the pouches approximate. The external traction technique is reported to expedite approximation of the pouches, thus allowing for earlier primary repair (10 to 14 days).
In addition to preoperative attempts to elongate the esophagus, many intraoperative techniques have been used to establish a primary esophageal anastomosis, either at an initial operation in the newborn period or at the time of a delayed operation after the elongation methods previously described have been used. In 1969, Livaditis et al described the technique of circular myotomy which can effectively lengthen the proximal esophagus. The use of balloon catheters inflated in the upper esophageal pouch to facilitate mobilization and subsequent circular myotomy is a useful modification of this method. Other technical modifications havebeen suggested including the use of a spiralupper pouch myotomy & short horizontal myotomies placed in rows. Several reports have suggested the use of adistal esophageal pouch circular myotomy in additionto proximal myotomy to achieve a primary esophagealanastomosis. Another method to elongate the upper pouch - described by Gough - involves the creation of a full-thickness anterior flap of theupper pouch wall, which when folded distally;it can be rolled into a tube and attached to thelower esophageal segment.Despite the long-held opinion that the blood supply to the distal esophagus is tenuous andmay be compromised by mobilization, many surgeonshave found that the distal esophagus can be mobilized to facilitate a primary anastomosis. With this approach, some of the fundusof the stomach can be brought up into the chest to facilitate anastomosis. Taking this concept further, Schärli described a combined abdominal and thoracic procedure in which distalesophageal elongation was achieved by ligation and division of the left gastric artery, diagonaldivision of the lesser curvature of the stomach, and mobilization of the gastric cardia and fundus into thechest to achieve primary esophageal anastomosis. A partial fundoplication is recommended to treat theanticipated GER. A Collis gastroplasty with Nissen fundoplication has also beendescribed as a means of lengthening the distal end of the esophagus. Rao et al treated 4 patients with long gap pure esophageal atresia after an initial gastrostomy and cervical esophagostomy at birth with fundal tube technique. The technique consisted of mobilization of the distal esophageal stump, division of the left gastric artery, mobilization of upper half of stomach, then both walls of the stomach were incised in the region of the fundus starting on the lesser curvature in such a way that a tube was created out mostly of the fundus, and the native esophageal stump appears to be an extension of this neoesophagus.
The use of postoperativehead flexion, paralysis, and mechanical ventilatory support in long gap EA after a substantially tense anastomosis minimizesthe risk for anastomotic disruption & allows successful repair of the long gap.
Every effort should be made to conserve the native esophagus, as no other conduit can replace its function in transporting food from the oral cavity to the stomach satisfactorily. Despite the many methods and innovations developed to achieve esophageal continuity in infants with EA, the esophagus may need to be replaced. Numerous operative procedures have been described for esophageal replacement in infants with EA. The colon was the first conduit used as esophageal replacement. Other alternatives include the stomach, jejunum & ileum.
Whenever the surgeon uses the stomach as an esophageal substitute, either one of two techniques is performed: total gastric transposition or gastric tube esophagoplasty. The gastric transposition (or pull-up procedure) is performed by mobilizing the entire stomach on a vascular pedicle, relocating the entire stomach into the mediastinum, and creating an anastomosis to the cervical esophagus in the neck. A pyloroplasty or pyloromyotomy is added to prevent delayed gastric emptying. Laparoscopic techniques can be used for gastric pull-up procedures in children with long gap esophageal atresia.
Gastric tubes include a reversed gastric tube & an isoperistaltic gastric tube. They are constructed with a stapling device from the greater curve of the stomach. They are constructed from the antrum up with the blood supply based on the left gastroepiploic artery (reversed gastric tube) or from the fundus down with the blood supply based on the right gastroepiploic artery (isoperistaltic gastric tube).
The jejunum has been used in esophageal replacement. One option in using the jejunum is the use of a pedicled graft. The jejunum is transected distal to the ligament of Treitz, the proximal end of the loop is brought up through the thorax into the neck to join the esophagus, the distal end is anastomosed to the stomach and intestinal continuity is restored by a jejuno-jejunal anastomosis. Cusick et al have described the use of a pedicled graft supported by a microvascular anastomosis in the region of the proximal anastomosis in order to ensure a well- vascularised graft. Transfer of a free jejunal graft with microvascular anastomosis is also an option. It provides a tension-free graft and prevents loss of bowel in the preparation of a pedicled graft, but it is technically demanding and may result in a high failure rate.
Ileal pedicle graft interposition extends the armamentarium for esophageal replacement in children. Harvesting and esophageal interposition of a pedicle graft of terminal ileum is done. The terminal ileum is transected just proximal to the ileo-caecal valve. The right colon, appendix and ileo-caecal valve are removed and bowel continuity between the proximal ileum and left transverse colon is restored anterior to the vascular pedicle of the terminal ileum.
Colonic interposition represents the most commonly used technique for esophageal replacement. Either the right or left colon can be used. The graft is placed retrosternally, behind the hilum of the lung or in the posterior mediastinum. In the retrosternal technique, a retrosternal tunnel is developed, the graft is passed behind the stomach, esophago-colic anastomosis is done and the colon is fixated to the neck muscles. The gastro-colic anastomosis is performed to the anterior gastric wall with a wrap from the anterior gastric wall. The colon should be fixed to the edges of the tunnel. In the retrohilar technique, the left colon based on the ascending branch of the left colic artery is placed isoperistaltically or based on the middle colic artery is placed in an antiperistaltic manner. The colon graft is passed in a retro-gastric and retro-pancreatic direction and then through a separate lateral incision in the posterior diaphragm. The colon is passed behind the hilum of the left lung and into the neck. Esophago-colic anastomosis is done at the proximal end. The distal end is anastomosed either to the distal stump of esophagus or preferably to the posterior wall of the stomach. Freeman & Cass modified the procedure by placing the colon in the posterior mediastinum in the site of the normal esophagus. A gastro-colic anastomosis is performed at the cardia with 270° anti-reflux wrap of the stomach. The colon should be fixed to the edge of the hiatus. Pyloroplasty is done in all cases with posterior mediastinal replacement.