Causes, Treatment and Prevention of Esophageal Fistulas in Anterior Cervical Spine Surgery

Abstract

Objective

To evaluate the causes, treatment and prevention of esophageal fistulas after anterior cervical spine surgery.

Method

Between January 2004 and December 2011, 5 of 2348 patients who underwent anterior cervical surgery in our hospital developed esophageal fistulas (three male and two female patients, average age 34 years). Their diagnoses were cervical injuries (three), cervical spondylosis (one) and cervical tuberculosis (one). Their esophageal fistulas were treated by debridement and exploratory surgery, primary suturing of the perforation and/or sternocleidomastoid myoplasty. If conservative treatment failed or esophageal fistula recurred, plate removal was offered. Postoperative treatment included esophageal rest, enteral nutrition, wound drainage, and antibiotics. Methylene blue was used to evaluate results.

Result

An esophageal fistula was discovered during anterior cervical surgery in one patient and primary suturing performed. In four patients, fistulas were diagnosed after anterior cervical decompression and fusion. In one of these, only debridement and exploratory surgery were required. In another, a perforation was sutured during debridement and exploratory surgery. In the third, internal fixation was removed because of failure of prolonged conservative treatment. In the fourth, the esophageal fistula recurred repeatedly; he required removal of the hardware and reinforcement with a sternocleidomastoid muscle flap. At 6–48 months follow‐up, all patients were in good condition, symptom free, and without cervical instability or infectious spondylitis.

Conclusion

Successful management of esophageal fistula after anterior cervical spinal surgery depends on primary closure of the perforation with or without muscle flaps, surgical drainage, esophageal rest and nutritional support, and removal of hardware if necessary. Prevention consists of careful surgery and gentle tissue handling.

Introduction

Anterior cervical decompression and fusion (ACDF) is an effective procedure for treatment of cervical spondylotic disease, cervical spine trauma, tuberculous cervical spondylitis and cervical tumors. Esophageal fistula after anterior cervical surgery is rare, but potentially fatal, with an incidence of 0.04%–0.25%1, 2, 3, 4. Complications associated with esophageal perforation include wound infection, fixation failure, osteomyelitis, mediastinal infection, spinal infection and death.

The purpose of this study was to evaluate the causes, treatment and prevention of esophageal fistulas in anterior cervical spine surgery. Between January 2004 and December 2011, 2348 patients underwent anterior cervical surgery in our hospital and five of them developed esophageal fistulas. This retrospective clinical study evaluates these five patients.

Materials and Methods

All patients were treated in a single medical institution. Data was collected by an independent senior spinal surgeon who was not involved in either the surgery or postoperative management of these patients. Inclusion criteria were: (i) ACDF; (ii) ACDF combined with posterior cervical spine surgery; and (iii) intraoperative or postoperative diagnosis of esophageal fistula. Exclusion criteria were: (i) any esophageal disease, deformity, or surgical history; and (ii) previous upper cervical spine surgery.

Patient Characteristics

Five patients developed esophageal fistulas after anterior cervical spine surgery. They included three males and two females with an average age of 34 years (14–48 years). Their relevant clinical variables are shown in Table 1.

Table 1.

Relevant patient variables

Case	Age (years/sex)	Diagnosis	Frankel/JOAa	Cervical surgery	Time of esophageal fistula	Diagnosis of esophageal fistula
1	32/F	C5,6 fracture/dislocation with quadriplegia	A	Anterior C5 vertebral subtotal, titanium mesh placement and titanium plate fixation	24 days after surgery	Wound fluid, puncture methylene blue
2	34/M	C6,7 fracture dislocation with incomplete paralysis	B	Posterior C6,7 fracture reduction and fixation; anterior C6,7 discectomy, bone graft and fixation	37 days after surgery	Wound fluid, puncture food
3	48/M	C4 burst fracture with incomplete paralysis	C	Anterior C4 vertebral subtotal, titanium mesh placement and titanium plate fixation	18 days after surgery	Wound fluid, puncture food
4	42/F	Cervical spondylosis myelopathy, C4‐5, C5‐6 disc herniation	9	Anterior C5 vertebral subtotal, titanium mesh placement and titanium plate fixation	5 days after surgery	Wound fluid, puncture food
5	14/M	C7‐T1 tuberculosis recurrence	—	Posterior debridement and fusion combined with anterior debridement, removal of hardware and instrumentation‐fusion	During surgery	Perforation of right‐posterior esophagus

^aNerve function evaluation: Frankel grade for cervical spine injuries, Japanese Orthopedic Association scores for cervical spondylosis.

Surgery for Esophageal Fistula

When an esophageal fistula is noticed during ACDF, a thoracic surgeon should immediately be consulted. To achieve maximum preservation of the tissue surrounding the esophageal fistula, primary suture of such perforations are performed and hemostatic gauze and gelatin sponge placed between the perforation and plate. Any abscesses are drained with a suction drain and an indwelling gastric tube is inserted. If there is serious edema of esophageal tissue, a sternocleidomastoid myoplasty is effective and indwelling gastric and drainage tubes inserted.

For esophageal fistulas diagnosed after ACDF, debridement and exploratory surgery is performed jointly by spine and thoracic surgeons. If the site of esophageal perforation is evident, this is subject to primary closure, which may be reinforced with a sternocleidomastoid muscle flap. A suction drain and stomach tube are inserted and the wound closed in multiple layers. If no site of perforation is identified in the esophagus, a suction drain and stomach tube are inserted.

After such surgery for esophageal fistula, if prolonged subsequent conservative treatment is ineffective, or conservative treatment is initially effective but an esophageal fistula recurs after oral intake is resumed, the patient is offered surgical removal of the plate with repair of the esophageal fistula.

Non‐surgical Management of Esophageal Fistula

After surgery, patients are confined to bed for 4–6 weeks (2 weeks in the case of cervical spondylotic disease). Before ambulation with a Philadelphia collar, venous color Doppler ultrasound examination of the lower limbs is performed to detect any deep venous thrombosis. A cervicothoracic orthosis is used by patients in whom hardware has been removed until imaging studies show that spinal fusion has occurred.

Intravenous antibiotics are given for 1 week. The patient is strictly forbidden anything by mouth and given enteral nutrition by nasogastric tube for 3 weeks postoperatively. Patients with cervical tuberculosis receive quadruple chemotherapy and are supervised carefully while receiving this.

Methylene blue ingestion is used to evaluate the perforation, drainage of methylene blue from the suction drain indicating that healing has not occurred. Repeat methylene blue ingestion studies are used to assess healing of the perforation. Three days after methylene blue ingestion studies have been negative, oral intake of semi‐liquid food is permitted for one week. If the patient is free of discomfort after three days, the esophageal fistula has healed.

Results

An esophageal fistula was discovered during anterior cervical surgery in one patient and primary suture of this perforation performed. In four patients, esophageal fistulas were diagnosed after ACDF. The perforation was sutured during debridement and exploratory surgery in one patient whose site of esophageal perforation was identified during exploratory surgery. Due to failure of conservative treatment, internal fixation was removed in one case. In another case, the esophageal fistula recurred repeatedly; this patient's hardware was removed and the area reinforced with a sternocleidomastoid muscle flap.

All patients recovered uneventfully and were able to swallow safely after conservative treatment for 9–61 weeks. During 6–48 months of follow‐up, the patients remained in good condition, symptom free, and without cervical instability or infectious spondylitis. Neurologically, an average increase of one Frankel grade5 was achieved in patients with cervical spinal fracture and of six in Japanese Orthopaedic Association6 scores in cervical spondylotic patients.

Typical Case

A 34‐year‐old man had a fracture‐dislocation at the level of C₆–C₇ resulting in paraplegia (Frankel B). His dislocation was reduced via a posterior approach with fixation (M6, Medtronic, Atlantis, FL, USA), followed by anterior cervical decompression and fusion with a plate and screws (Medtronic). An esophageal fistula was diagnosed by the presence of food in his wound fluid 37 days after surgery. Debridement and exploratory surgery were performed, but the site of esophageal perforation could not be identified. After conservative treatment for 18 weeks, the esophageal fistula had still not healed. His anterior hardware was removed, after which the esophageal fistula resolved within 7 weeks. At final follow‐up, 24 months after the first surgery, the patient was in good condition and symptom free, and his C_4–5 segment had fused without instability. The Frankel grade was D (Fig. 1).

Figure 1.

A 34 year‐old man had a fracture‐dislocation at the level of C ₆–C ₇ with paraplegia. An esophageal fistula was diagnosed 37 days after ACDF. (a, b, c) Preoperative X‐ray films and CT scan images showing a fracture‐dislocation at the level of C ₆–C ₇. (d, e) Postoperative X‐ray films showing reduction of C ₆–C ₇. (f, g) CT scan images showing the presence of esophageal fistula. (h, i) At final follow‐up, 24 months after surgery, X‐ray films showing obvious C _4‐5 segment fusion without instability.

Discussion

In 1985, Balmaseda and Pellioni were the first to report esophageal fistula after anterior cervical spine surgery7. The most frequent clinical symptoms are neck/throat pain, dysphagia, fever and subcutaneous emphysema. Basic treatment consists of surgery with drainage of abscesses, primary closure of the perforation if possible, parenteral nutrition and antibiotic therapy.

Causes of Esophageal Fistula in Anterior Cervical Spine Surgery

Early presentations are mostly caused by direct injury to the esophagus by sharp instruments or retractor blades8. Delayed perforations are mainly caused by screw pull‐out, plate rupture or loosening, and graft dislodgment8, 9, 10. In addition to the above reasons, predisposing factors include:

1. Esophageal injury associated with cervical spinal trauma, esophageal inflammation, edema and hematoma associated with tuberculosis spondylitis. Gaudianez et al. reported 44 cases of esophageal fistula in anterior cervical spine surgery; 34 of these cases had cervical fracture‐dislocations11. Patel et al. thought that cervical spine injury was the risk factor for esophageal fistula in anterior cervical spine surgery2.

2. Rejection of hardware.

3. From the anatomical point of view, posteriorly the esophagus lacks serosa and its wall is thinner. Lanier's triangle, in the posterior wall of the esophagus, is the most common site for esophageal perforation, 50% of esophageal fistulas reportedly occurring at this site12.

   In our study, the diagnoses were cervical injury in three patients and cervical tuberculosis in one. In two cases, healing of the esophageal fistula was achieved only after removal of hardware.

Diagnosis of Esophageal Fistula after Anterior Cervical Spine Surgery

According to most reports, the time to diagnosis of esophageal fistula is between 5 days and 12 weeks after anterior cervical surgery1, 2, 7, 11, 12. The earliest reported time to diagnosis is 38 hours after anterior cervical surgery3. The commonest presenting symptoms are local abscess, fever and other signs of infection, dysphagia, and neck swelling. Other symptoms include neck and throat pain, odynophagia, and hoarseness.

In addition to direct observation at the time of surgery, diagnosis is made by endoscopy and/or contrast studies, although these may give false‐negative results8, 10, 13. Methylene blue ingestion is the other mode of diagnosis of fistulas13. We recommend methylene blue ingestion study every 2–3 weeks to evaluate possible perforation during follow‐up. This method is easy to implement, patients readily comply, and it has no significant side effects.

Treatment of Esophageal Fistula after Anterior Cervical Spine Surgery

Treatment depends on the time that the perforation is recognized. If it is diagnosed intra‐operatively, primary closure of the perforation is possible, and surgical drainage is required. In early perforations, repair of the lesion can be achieved with or without muscle flaps14, 15, 16, 17. In cases of late diagnosis, debridement, drainage, and removal of hardware are recommended to allow spontaneous closure of the lesion8, 10. Primary closure of complex esophageal injuries may not be advisable because of the high incidence of esophageal strictures.

For patients who have undergone surgery for esophageal fistulas in whom prolonged conservative treatment is unsuccessful, or in whom esophageal fistula has recurred, plates should be removed8. The reasons for this recommendation are as follow: (i) pressure from the hardware causes ischemia around the fistula; (ii) the metallic foreign bodies used for fixation stimulate formation of fistulas; and (iii) these patients are likely to reject the metallic hardware in any case. Two of our patients did not heal after prolonged strict conservative treatment. After we removed their hardware, their esophageal fistulas healed.

Non‐surgical treatment is essential for management of anterior cervical surgery‐related esophageal fistulas. Conservative treatment includes bed rest followed by external orthotic support, local drainage, tube feeding, and administration of parenteral nutrition and antibiotics.

Prevention of Esophageal Fistula in Anterior Cervical Spine Surgery

The keys to reduce the complications of esophageal fistula after anterior cervical surgery are careful surgery and attention to the following of technical points: (i) avoidance of direct damage to the esophagus by sharp instruments; (ii) avoidance of continuous stretching of the esophagus; (iii) avoidance of compression of the esophagus by the plate; and (iv) improvement in techniques of bone graft and installation. In patients with cervical spine injuries or cervical tuberculosis undergoing anterior cervical surgery, the esophagus may be damaged or inflamed; therefore, surgeons should be particularly mindful about avoiding esophageal fistula in these aptients.

Because esophageal perforation complications can occur as late as 10 years after surgery, these patient should undergo regular, long‐term follow‐up13, 17. They should be warned at discharge to return immediately if they experience symptoms of swallowing or upper airway compromise.

In summary, successful management of esophageal fistulas after anterior cervical spinal surgery depends on primary closure of the perforation with or without muscle flaps, surgical drainage, esophageal rest, nutritional support, and removal of hardware if necessary. Preventive measures consist of careful surgery and gentle handling of tissues.