Video-Assisted Thoracoscopic Surgery to Treat Hydatid Disease of the Thorax in Adults: Is It Feasible?

Introduction

Hydatid disease is caused by Echinococcus granulosus. In humans, it is a chronic and debilitating zoonotic larval cestode infection, which is transmitted to dogs by livestock, particularly small ruminants. Human hydatid disease is found in almost all rural areas of underdeveloped and developed countries. ¹ Despite advances in the control of the infestation such as intermediate and final host vaccination and attention to environmental sanitation, hydatid disease has not been eradicated. ² Thoracic hydatid disease still has an important place in the daily practice of thoracic surgeons in endemic regions.

Treatment for thoracic hydatid disease includes complete surgical removal of cysts. ³ The standard surgical approach is open surgery (thoracotomy), which is notorious for involving a painful surgical wound, and it can also lead to respiratory complications and chronic pain syndrome. ⁴ In our study, a selected series of patients with pulmonary and intrathoracic but extrapulmonary (mediastinal) hydatid cysts who underwent video-assisted thoracoscopic surgery (VATS) were evaluated in terms of reliability of the method and appropriate patient selection.

Subjects and Methods

Surgery

VATS was performed with the patient under general anesthesia with double-lumen intubation. The three-port (11-mm trocars) technique was used with the patient in the lateral decubitus position. Pulmonary echinoccocal cysts were removed through wedge resection (by using a stapler) with safety margins of the parenchyma (Fig. 1). Mediastinal cysts were removed completely with a portion of surrounding fat and pleural tissue. Hydatid fluid was aspirated before any intact and large cysts were excised from the thorax. A large-bore (24–28 French) chest tube was inserted into the camera port in each patient and evacuated in the first 48 hours.

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FIG. 1.

(a) A 78-year-old woman underwent transthoracic fine-needle biopsy because of a suspected mass in the lingular segment of the left upper lobe. Histopathology revealed an echinococcal cyst. (b) The cyst was removed with a wedge resection via video-assisted thoracoscopic surgery. (c) A complicated (perforated and supurated) hydatid cyst is seen.

Results

In total, 12 patients underwent 13 operations to treat intrathoracic hydatid cysts. Their mean age was 32.3 years (range, 18–78 years). Of the 12 patients, 8 (67%) patients were female, and 4 (33%) were male. Three patients (25%) presented with intact pulmonary cysts, 5 (42%) with ruptured pulmonary cysts, and 4 (33%) with mediastinal intact cysts. Only 1 patient presented with bilateral cysts. VATS was successful in all patients. Surgeries took 30–100 minutes (mean, 51.5±21.7 minutes), and no patient required conversion to thoracotomy. The mean length of hospital stay was 2.9 days (range, 2–6 days). Histopathology revealed E. granulosus in all patients. No operative or hospital deaths were observed in the series, and no patients had a major complication. Prolonged hospitalization (6 days) because of an air leak was the only minor complication. Patients were followed up for 10–55 months (mean, 29 months). The follow-up period was uneventful, and no recurrences were observed.

Discussion

Echinoccocal cysts are a major problem in endemic areas, particularly in developing countries. The liver and lungs are the most common sites for the parasite. ³ Treatment for a pulmonary hydatid cyst involves complete excision with maximal preservation of the lung parenchyma. ⁵ Cystotomy or cystotomy plus capitonage are preferred surgical methods in both complicated and uncomplicated types of hydatid cysts. ⁶ Nonanatomic resections such as pericystectomy and wedge resection and anatomic resections such as segmentectomy and lobectomy may be required in cases of complicated thoracic hydatid disease. ⁷ The surgical principles of cystotomy include avoiding rupture of the cyst and controlling bronchial air leaks in the residual cavity. Extreme care is recommended during enucleation of the cyst to avoid spilling parasitic material into the surgical field. ⁸ Bronchial air leaks from the cyst cavity may cause serious complications such as empyema and bronchopleural fistula following removal of pulmonary cysts.

As a minimal invasive surgery, VATS has become standard practice for mediastinal and pulmonary cysts. In hepatic echinococcal cysts, minimal invasive surgery (laparoscopy) has proven itself in terms of feasibility and safety.^9,10 However, echinoccocal cysts of the thorax are still candidates for open surgery (thoracotomy). Surgical treatment of pulmonary hydatid cysts via VATS, such as parenchyma-preserving surgery, with cystotomy plus capitonage, has some limitations, including difficulties controlling bronchial air leaks and the risk of perforation during enucleation of the membranes. The video-assisted mini-thoracotomy approach may allow enucleation and capitonage of the cysts ¹¹ ; however, this method cannot be considered as completely minimally invasive surgery because of the need for spreading of the ribs and a skin incision of more than 5 cm. In our series, 8 (70%) patients with pulmonary hydatid cysts underwent wedge resection via VATS with the three-port (trocar) technique. Complicated and uncomplicated (intact) types of echinoccocal cysts were completely removed. Postoperative functional capacities of the patients did not deteriorate because only a small amount of healthy lung parenchyma was sacrificed during wedge resection of the cysts.

Mediastinal echinoccocal cysts are rare and represent only 0.1%–4% of all hydatidosis cases. Most mediastinal echinococcosis involves secondary cysts that occur as a result of ruptured paramediastinal cysts or penetration and migration of a subdiaphragmatic cyst. ¹² Primary mediastinal hydatid cysts are very rare and make up only 0.1% of hydatid diseases. ¹³ Eroğlu et al. ¹⁴ reported a series of 427 operated intrathoracic hydatid cysts, of which only 11 (2.6%) were mediastinal cysts. Differential diagnosis of a mediastinal hydatid cyst is very difficult because imaging findings and clinical symptoms may not provide a clear distinction between congenital and infectious cysts. In our series, all mediastinal cysts were secondary cysts and constituted 3.4% of the series. Patients with mediastinal cysts presented with a history of liver hydatid disease (Fig. 2). Unlike pulmonary hydatid cysts, mediastinal cysts were removed regardless of size and location. These cysts were enucleated and aspirated before being removed from the thorax.

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FIG. 2.

(a) A 31-year-old man underwent video-assisted thoracoscopic surgery to treat the right paracardiac cyst (white arrow). (b) He had a history of treatment for hydatid cyst of the liver 3 years ago. A calcified hydatid cyst is seen in computerized tomography of the abdomen (white arrow).

Thoracotomy incisions provide a wide range of exposure, so all thoracic surgical procedures can be applied. However, major disadvantages such as postoperative early and chronic pain, diminished shoulder and respiratory function, and cosmetically unappealing scar tissue directed us to less invasive surgery. ⁴ The known advantages of VATS, including less pain, shorter hospital stay, and better cosmetic and functional results, were applicable here as well. In our series, cosmetic results were as important as pain and duration of hospitalization because most of the patients were young. VATS was also a safe method not only for early but also late outcomes. No recurrences were observed during the 29-month mean follow-up.

In conclusion, this study demonstrated that VATS resection of intrathoracic hydatid cysts is feasible and safe for selected patients. Although only small and peripheral pulmonary echinoccocal cysts may appear to be suitable for VATS, central and large cysts are also candidates for this less invasive surgical technique. Mediastinal hydatid cysts are also eligible for VATS, but the surgeon should be very careful to prevent rupture.