Pharyngocutaneous fistula caused by dried ‘Kombu’ (edible seaweed) after total laryngectomy

Abstract

The most common early complication after total laryngectomy is pharyngocutaneous fistula (PCF). However, there are no reports of PCF after total laryngectomy caused by ‘Kombu’ (edible seaweed) as a foreign body in the digestive tract. A 68-year-old Japanese man had undergone total laryngectomy 5 years previously. He presented with PCF, neck swelling and pain. Video endoscopy showed that a dark green foreign body obstructed the digestive tract. PCF was successfully treated via emergency surgery comprising abscess drainage, foreign body removal and fistula closure. The foreign body was kombu. Clinicians who perform total laryngectomy should know the potential dangers of consuming hygroscopic food items that can cause bolus obstruction of the upper digestive tract and pharyngeal abscess and perforation.

Background

Total laryngectomy is the standard for treating advanced stage or recurrent laryngeal cancer or pharyngeal cancer. However, total laryngectomy can result in a number of postoperative complications. Among the early complications (within 3 months postoperatively), the most common are pharyngocutaneous fistula (PCF) (50%), wound dehiscence (29%) and haemorrhage (2%), while the late complications include dysphagia (25%) and stenosis of the tracheostoma (21%).¹ The rate of PCF following total laryngectomy reportedly ranges from 8% to 22%,² and typically occurs 8–13 days postoperatively.¹ Late PCF mainly results from residual tumour or cancer recurrence.¹ The risk factors for PCF include preoperative radiotherapy, positive ipsilateral and contralateral lymph nodes, accompanying systemic disease, preoperative and postoperative haemoglobin (Hb) <12.2 g/L, and a postoperative albumin (Alb) level <3.5 g/dL.² Currently, there are no previous reports of PCF after total laryngectomy caused by a foreign body in the digestive tract.

‘Kombu’ is an edible seaweed that is widely eaten in East Asia. When moistened with water, kombu easily expands and becomes sticky, making it indigestible to the human gut.³ Cases involving kombu as a foreign body in the digestive tract have not been reported throughout Asia, with the exception of a few cases occasionally reported in Japan.^4–9 Here, we present a rare case of PCF caused by kombu as a foreign body in the digestive tract that occurred 5 years after total laryngectomy in a patient with laryngeal cancer.

Case presentation

A 63-year-old Japanese man underwent total laryngectomy and prevenient unilateral selective neck dissection (Ⅰ–Ⅴ) for the treatment of left subglottis laryngeal cancer (pT3N0M0). The surgery lasted for 5.5 hours and was performed by the usual method, involving a U-shaped skin incision, 3–0 vicryl sutures and the T-type pharyngeal closure technique. Transfusion was not required. The patient did not present with any wound infection, and his swallowing was smooth 10 days after surgery. Fourteen days after the surgery, a small PCF occurred in the pharyngo-oesophageal anastomotic region, but the complication resolved within a few days after placement of a few 4–0 vicryl sutures. The patient did not undergo preoperative radiotherapy and did not have positive ipsilateral and contralateral lymph nodes, accompanying systemic disease, preoperative and postoperative Hb <12.2 g/L, or a postoperative Alb level <3.5 g/dL.

Five years later, the patient had experienced an episode of throat clogging during a meal, but the incident was easily resolved at that time. The patient did not have any fever, chills or respiratory symptoms. After 3 days, the patient was admitted to our department, presenting with anterior neck swelling and pain for 1 day. Percutaneous redness, heat, swelling and PCF were observed above the tracheal stoma. The patient had normal vital signs, and he did not have any comorbidities such as diabetes mellitus or an immunodeficiency.

Video endoscopy indicated the presence of a dark green foreign body in the pharyngo-oesophageal anastomotic region. Contrast CT of the neck revealed an abscess of about 28×15×25 mm around the pharyngo-oesophageal anastomotic region (figure 1). Biopsy from the PCF edge revealed no recurrence of carcinoma. Blood exam revealed normal white cell count (6.9x10⁹L), C reactive protein (0.68 mg/dL), Hb (14.0 g/L) and Alb (3.8 g/dL).

Figure 1.

Contrast CT scan image of the neck: (A) axial, (B) coronal and (C) sagittal views. A ring enhancement area (28×15×25 mm, arrows) was present in the pharyngo-oesophageal anastomotic region.

An emergency operation was performed, consisting of abscess drainage, foreign body removal (figure 2) and half closure of the PCF. Bacterial culture from the abscess showed Streptococcus anginosus. Antibiotics, penicillin 4 g/day, were started on the day of surgery. The residual half fistula was closed with a few 4–0 nylon sutures 1 week later (figure 3). The postoperative period was uneventful. Seven days postoperatively, oral feeding was initiated and the patient was discharged after being educated on appropriate swallowing methods and food types. Three years after fistula repair, there has been no recurrence of carcinoma and PCF, and the patient is able to ingest food orally.

Figure 2.

Photograph of the removed foreign body, which consisted of kombu. It was not digestible and the shape was maintained. The size was approximately 4.5 cm.

Figure 3.

Postoperative photograph of the neck. The residual half fistula was closed (arrows) with a few sutures 1 week after the foreign body removal surgery. The trachea stoma is indicated by arrowheads.

Outcome and follow-up

The patient is alive without recurrence of carcinoma and PCF, and is able to ingest food orally now.

Discussion

The risk factors for PCF include preoperative radiotherapy, positive ipsilateral and contralateral lymph nodes, accompanying systemic disease, preoperative and postoperative Hb <12.2 g/L, and a postoperative Alb level <3.5 g/dL.² Currently, there are no previous reports of PCF caused by a foreign body in the digestive tract after total laryngectomy.

From 2005 to 2015, total laryngectomy was performed in 155 patients in our department. Twenty of these patients (12.9%) experienced PCF as a result of digestive tract scarring and stricture, but only the present patient (0.6%) experienced PCF as a result of postoperative foreign body obstruction in the digestive tract. Physiologically, the pharynx and oesophagus share similar mucosal structures and epithelial cells.¹⁰ Therefore, a foreign body in the pharynx after total laryngectomy would have the same pathophysiological condition as a foreign body in the oesophagus. In the general population, oesophageal foreign body obstruction mostly occurs in the elderly or young people, with the lesion often coinciding with a physiological stricture, and the stricture origin can be at the level of the oesophagus, carina or diaphragm.¹¹ The cause of oesophageal foreign body obstruction depends on various factors, including body species, digestive tract condition, and swallowing or digestion functionality.¹² The types of foreign bodies that are found in normal digestive tracts differ from those found in postoperative digestive tracts or digestive tracts with pathological strictures.¹³ A foreign body in a normal digestive tract is likely to be caused by non-foodstuffs, such as dentures or a press through packaging, while foreign bodies in postoperative digestive tracts or digestive tracts with pathological strictures are almost entirely caused by foodstuffs.¹¹ Previous studies have reported that in cases of advanced oesophageal cancer and postoperative digestive tract scarring and stricture, food items that contain beans, seeds and seaweed often become foreign bodies because the digestive tracts are narrower.¹² In addition, Yamada et al ¹³ reported that swallowing or digestive functionality is important to avoid a dietary-related oesophageal foreign body. In general, elderly individuals tend to have weakened pharyngeal reflexes, mastication function and digestive function.

Kombu is an edible seaweed that is widely eaten in East Asia. Cases of kombu as a foreign body have never been reported throughout Asia, with the exception of some reports in Japan (table 1).^4–9 In Japan, kombu may be eaten as dry small strips about 5–6 cm long and 2 cm wide. It contains the entire family of obscure enzymes that break down complex sugars that are normally indigestible to the human gut, and it expands and becomes sticky when moistened, and is known to increase to three times its size when exposed to water or saliva.³ This means that dried kombu or similar foodstuffs, like chia seeds, basil seeds and agar, are small and easy to swallow, but not easy to digest after the absorption of water or saliva.

Table 1.

Summary of published cases of patients who experienced foreign body obstruction with kombu

Reports	Terms (year)	n	Frequencies	Causes
Sasaki et al 8	1907–1931	3	3/508	Normal (young person): 1 Stricture of digestive tracts: 2
Yamakawa9	1931–1951	8	8/1550	Stricture of digestive tracts: 8
Shirabe7	1976	1	–	Normal (old person): 11

Summary of published cases of patients who experienced foreign body obstruction with kombu in the oesophagus and pharynx or the larynx around the head and neck. The numbers in the frequency column indicate the number of patients who experienced a kombu foreign body obstruction in those areas relative to the total number of obstructions with other types of foreign bodies.

In the present case, the patient ingested dried kombu, which lodged as a foreign body in the digestive tract as a result of postoperative stricture. Although kombu rarely becomes a foreign body, dried kombu is a potential foreign body obstruction in young children and individuals with cognitive decline. Sasaki et al ⁸ reported that a 2-year-old boy swallowed kombu without chewing, resulting in stenosis of the larynx and dyspnoea. Shirabe⁷ reported that an elderly patient ingested a dried square of kombu while inebriated, which resulted in digestive tract damage and infection. The present patient tended to eat without adequate mastication. These poor mastication habits were revealed by his family. Mild digestive tract stricture after total laryngectomy does not necessarily influence swallowing and digestive functionality; however, clinicians should educate patients and their family to be cautious about foodstuffs that are indigestible, easily expandable and sticky with moisture. In addition, the pharynx of this patient may be fragile by the small PCF after total laryngectomy. Patients who undergo total laryngectomy may be able to safely ingest kombu if it is boiled or cooked until tender. In the present case, we did not perform deglutition studies (dynamic imaging, such as video fluoroscopic swallowing examination) or cognition studies during follow-up. These studies might help in understanding the clinical state of this patient. We suggest that these types of studies should be performed after neck surgery.

Learning points.

• We present a rare case of pharyngocutaneous fistula caused by kombu as a foreign body in the digestive tract 5 years after total laryngectomy.

• Hygroscopic food items may increase the risk of bolus obstruction and disruption of upper digestive tract anastomoses, especially if normal mastication and deglutition mechanics are compromised.

• Clinicians who perform total laryngectomy should know the potential risks of eating hygroscopic foodstuffs, such as dried kombu, and the proper methods of cooking.