Surgical treatment of caustic esophageal strictures
Alkali-induced injury – Ingestion of alkali (eg, ammonia or sodium hydroxide) acutely results in a penetrating injury called liquefactive necrosis. The injury extends rapidly (within seconds) through the mucosa and wall of the esophagus towards the mediastinum until tissue fluids buffer the alkali. Extensive transmural damage may result in esophageal perforation, mediastinitis, and death.
In the stomach, partial neutralization of the ingested alkali by gastric acid may result in more limited injur. Among patients with alkaline ingestions, gastric injury is most common in those who ingest relatively large volumes (200 to 300 mL). Duodenal injury is much less common as compared with the stomach and esophagus, occurring in 30 percent in one series, in contrast to 94 and 100 percent respectively.
The process of liquefactive necrosis usually lasts three to four days and is associated with vascular thrombosis and mucosal inflammation, resulting in focal or extensive sloughing and ulceration. Over the ensuing two weeks, the esophageal wall becomes progressively thinner because of sloughing and the development of granulation tissue and fibrosis. Re-epithelialization is usually complete one to three months later. The likelihood of stricture formation depends upon the depth of damage and degree of collagen deposition.
●Acid-induced injury – Acid solutions cause pain upon contact with the oropharynx, therefore the amount of acid ingested tends to be limited. Upper airway injuries are more common with ingestion of acid, perhaps related to their bad taste, which tends to stimulate gagging, choking, and attempts to spit out the ingested material. In contrast to alkaline solutions which are more viscous, acid preparations tend to pass quickly into the stomach, causing less esophageal damage.
As the acid flows along the lesser curvature of the stomach toward the pylorus, pylorospasm impairs emptying into the duodenum, producing stagnation and injury that is particularly prominent in the antrum. Food in the stomach tends to provide a protective effect. Acid ingestion typically produces a superficial coagulation necrosis that thromboses the underlying mucosal blood vessels and consolidates the connective tissue, thereby forming a protective eschar . Acid ingestion in sufficient concentration can cause esophageal and gastric perforation with peritonitis.
Esophageal squamous cell carcinoma
It is estimated that up to 30 percent of patients with caustic injuries develop esophageal cancer. In one study of 63 patients, the mean latency period for development of esophageal cancer was 41 years (range 13 to 71 years). Corrosive injury later in life was associated with a shorter latency period. Carcinoma at the site of previous lye stricture (scar carcinoma) has a better prognosis as compared with other causes of esophageal squamous cell carcinoma. This may be due to an earlier stage at diagnosis as the esophageal lumen at the level of the scarred esophagus is less distensible; as a result, dysphagia occurs earlier in the course of the disease. Scar tissue within the esophageal wall makes lymphatic spread and direct extension of the tumor less likely to occur before the onset of dysphagia. Scar carcinoma also responds better to combined surgical and radiation therapy.
CLASSIFICATION
Pathologic classification — Caustic injuries to the gastrointestinal tract are classified pathologically, similar to burns of the skin:
●First-degree injury – First-degree injury results from superficial mucosal damage and is characterized by focal or diffuse erythema, edema, and hemorrhage. The mucosal lining subsequently sloughs without scar formation.
●Second-degree injury – Second-degree injury is characterized by mucosal and sub-mucosal damage, ulcerations, exudates, and vesicle formation. Eventually, there is granulation tissue and then a fibroblastic reaction, producing a scar and possible stricture.
●Third-degree injury – Third-degree injury is transmural and is characterized by deep ulcers and black discoloration and perforation of the wall.
Severity grading
●Low-grade injuries – Endoscopy grade 1 to 2A or CT grade 1 injuries are considered low-grade injuries.
●High-grade injuries – Endoscopy grade 2B or 3 or CT grade 2 and 3 are considered high-grade injuries.
A simplified radiologic classification of CT findings and the corresponding endoscopic grade is as follows
•Grade 1 – Normal appearing organs. This usually corresponds to low grade 0 to 2a endoscopic burns
•Grade 2 – Wall edema, with surrounding soft tissue inflammatory change and increased post-contrast wall enhancement. This corresponds to more severe endoscopic burns.
•Grade 3 – Transmural necrosis as shown by the absence of post-contrast wall enhancement. This usually corresponds with grade 3b necrosis on endoscopy.
Zargar classification and its corresponding endoscopic description
| Zargar classification | Description |
| Grade 0 | Normal mucosa |
| Grade I | Edema and erythema of the mucosa |
| Grade IIA | Hemorrhage, erosions, blisters, superficial ulcers |
| Grade IIB | Circumferential lesions |
| Grade IIIA | Focal deep gray or brownish-black ulcers |
| Grade IIIB | Extensive deep gray or brownish-black ulcers |
| Grade IV | Perforation |
Esophageal stricture is one of the most common sequelae of caustic injury. Up to 70% of patients with grade IIB and more than 90% of patients with grade III injury are likely to develop esophageal stricture.
Peak development of strictures commonly starts on the 8th week post-ingestion, although it has been reported to occur as early as 3 wk. The timing of management is crucial in achieving long-term functional effects.
Non-surgical treatment of caustic esophageal stricture is
Endoscopic dilatation --> Bougie dilatation (Savary-Gilliard)
Esophageal stents -->
Surgical treatment of caustic esophageal strictures
Esophageal damage was primarily concentrated on the middle and 1/3 distal esophagus with a mean length of 5.2 cm.
Reason why esophageal injury frequently affects the distal part of the esophagus may be explained by lower esophageal sphincter activity, esophageal motor function, and anatomical specifications. On the other hand, this location provides the surgeon easier access for dissection and safe anastomosis to the proximal esophagus, which is usually unaffected by injury.
After esophagectomy, the best way to reestablish intestinal continuity is by colonic repositioning or gastric pull-up. Lesser anatomical changes and a single anastomosis requirement are the advantages of gastric pull-up.
Caustic liquid ingestion does not usually result in anatomical alteration in gastric structures and does not result in gastric perforation. Nevertheless, before surgery, it is important to examine the gastric anatomy by a contrasted X-ray study or other means (i.e., CT, endoscopy) to make sure the stomach is available for pull-up. Additionally, if the stomach is judged as ready for pull-up, the final decision should be given on surgery.
Esophagectomy can be performed via a transhiatal or transthoracic approach. The transhiatal approach is advantageous since it is not necessary to use a thoracic incision.
Surgical reconstruction – Patients with multiple failed attempts at endoscopic dilatations should be evaluated for reconstructive surgery which, in severe cases, may involve elective esophageal resection with esophagogastric anastomosis or colonic interposition. Most experts recommend delaying surgical reconstruction for six months to stabilize the injury.
The conduit is primarily stomach or colon. In the absence of significant gastric injury, a gastric transposition (pull-up) can often be performed. In experienced hands, minimally invasive esophagectomy through a combined thoracoscopic and laparoscopic approach may be preferred because it is associated with a decreased hospital stay and more rapid return to normal activities compared with standard esophagectomy. Although it is associated with high anastomotic stenosis rates, transhiatal esophagectomy and gastric pull-up with cervical anastomosis is a safe procedure that can be performed for the treatment of corrosive esophageal stricture.
If there is significant gastric injury, a colonic interposition can be used to create a new conduit. Either the right or left colon can be used as the conduit with comparable results; the choice should be based on the pattern of blood supply. The colonic conduit is most commonly placed in a retrosternal location (esophagocoloplasty). Whether to resect or bypass the native strictured esophagus in such cases is controversial. Risks of bypassing the native esophagus, which include esophageal cancer and a mucocele in the retained esophagus, must be weighed against the operative risk of esophagectomy in the presence of mediastinal scarring.
Right ileocolon as the esophageal substitute. The stomach of a lye-injured patient can be used as an alternative esophageal substitute if it has not sustained corrosive injury. In an acid-injured patient whose Right ileocolon lacked an adequate blood supply, the jejunum was used as an esophageal substitute. Lately, we have chosen the transverse and left colon as the esophageal substitute.
After resection for ingestion of a corrosive agent, the substernal route was favored for colon bypass. The posterior mediastinal route was not considered because of severe fibrosis. Patients with chronic severe esophageal strictures required bypass of the entire esophagus or replacement of the resected esophagus. In the bypass procedure, the thoracic esophagus was left in continuity with the stomach. The occurrence of mucocele and of cancer after corrosive stricture of the esophagus is rare. To decrease the risk of postoperative bleeding and to save time, esophagectomy was not routinely done. However, when there was a severe gastric stricture or esophagorespiratory fistula, esophagectomy was indicated.
Complication:
Pleural injury is the most common intraoperative complication of the transhiatal esophagectomy. It is commonly caused by a blunt dissection of the thoracic esophagus. Pleural integrity should be visually checked intraoperatively and an air bubble test performed via filling the operation field with water. Thoracic tube drainage.
Anastomotic leakage.
fistula formations and sepsis.
Anastomotic stenosis/stricture --> prevent by oblique and hand sewn noncontinuous anastomosis.
May need Colonic transposition
Graft necrosis.
Hemo-pneumothorax.
Aspiration Pneumonia.
Bacterial Pneumonoitis.
Peptic Colonic ulceration.
Bowel Obstruction
Complications After Esophageal Reconstructions
EarlyCervical anastomotic leakage
Pneumothorax, unilateral or bilateral
Abdominal anastomotic leakage
Wound dehiscence
Late
Intestinal obstruction
Stenosis of cervical anastomosis
Redundant esophageal substitute
Gastric mucocele with chronic anemia
Obstruction of esophageal substitute
Internal herniation
Obstruction of gastrojejunostomy caused by progressive antral stricture
Esophageal reconstruction
When esophageal dilatation is not possible or fails to provide an adequate esophageal caliber in the long-term, esophageal replacement by retrosternal stomach or, preferably, colonic interposition should be considered. (Level 3–4)
A laryngoscopic examination is mandatory prior to all esophageal reconstructions for caustic injuries. (Level 4–5)
The surgical bypass should be performed at least 6 months after caustic ingestion or emergency surgery since the “remodeling time”, i.e. time to stricture stabilization, is rather long. (Level 3–4)
Removal of the native esophagus in adult patients is largely debated. It seems advisable in children because of the higher risk of cancer in the long-term. (Level 5)
No randomized studies address the issue of which type of esophagoplasty is preferable. There are pros and cons for either right or left colon. An expert surgeon should do what he/she is used to do. (Level 5)
One-stage esophageal resection and replacement with a gastric conduit, instead of a bypass, is feasible and safe in patients with isolated distal esophageal strictures. (Level 5)
Minimally invasive/hybrid surgical techniques have been used with favourable results in selected patients. (Level 5)
Angiographic study of the vascular pedicle is not routinely recommended before colon interposition or bypass, with the exception of patients with previously failed surgical attempts. (Level 5)
Surgical revision is effective in patients who present with redundancy of the interposed colon years after retrosternal or mediastinal reconstruction. (Level 4)
Pharyngeal strictures are difficult to manage and require special expertise. Endoscopic laser therapy of pharyngo-laryngeal adhesions may prove useful in selected patients before definitive surgical treatment. Colopharyngoplasty for strictures involving the pharynx is a safe and effective procedure. In such circumstances, the restoration of upper digestive tract continuity requires concomitant esophageal and pharyngeal reconstruction with resection of all scar tissue. Treatment of pharyngeal and laryngeal injuries should be done at the same surgical session. Supraglottic laryngectomy and suprahyoid pharyngectomy are required if the epiglottis and/or the base of the tongue are involved (Level 4–5)
Temporary tracheostomy is mandatory during the rehabilitation training period after colopharyngoplasty. The postoperative re-education process is long and difficult and requires full cooperation from a psychiatric stable patient. (Level 5)
Advanced age has a negative impact on esophageal reconstruction. Patients older than 55 years are likely to experience severe complications, worse functional outcomes, and decreased long-term survival. For these reasons colopharyngoplasty should not be offered after this age limit. (Level 4)
Use of myocutaneous flaps and free jejunal grafts should be considered for salvage cervical esophageal reconstruction and restoration of alimentary transit after previously failed surgical attempts. (Level 4)
PROGNOSISPrognosis based on endoscopic grading is as follows:
●Patients with grades 1 and 2A have an excellent prognosis without significant acute morbidity or subsequent stricture formation.
●Patients with grades 2B and 3A develop strictures in 70 to 100 percent of cases.
●Grade 3B injuries are associated with an early mortality rate of 65 percent, and esophageal resection with colonic or jejunal interposition is required in most cases. In a large retrospective study, patients with grade 3B mucosal injuries were at greater risk of prolonged hospital stay (odds ration [OR] 2.4), ICU admission (OR 10.8), and gastrointestinal and systemic complications (OR 4.2 and 4.1, respectively).
Most deaths are due to the sequelae of perforation and mediastinitis. For patients who require pharyngeal reconstruction (colopharyngoplasty) during esophageal reconstruction because of severe pharyngoesophageal caustic injuries, long-term functional outcomes are poor
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