Giant bullae are space-occupying lesions that cause compression of the surrounding lung parenchyma with impairment of lung function. The bullae arise from emphysematous projections of destroyed lung tissue. Hence they differ from blebs, which are localized collections of air between visceral pleural layers without underlying parenchymal disease.¹ Giant bullae can be classified into three types based on morphology: Type I bullae have a narrow neck and are superficial, type II are superficial as well but have a broad neck, and type III are both broad and deep.²

CLINICAL PRESENTATION

The most common symptoms are dyspnea and chest pain. Pneumothorax, hemoptysis, and other complications such as infections that arise within the bulla can occur, but these sequelae are rare. Evaluation usually begins with a chest x-ray. Often a giant bulla is mistaken for pneumothorax, and the thoracic surgeon is consulted for placement of a chest tube. Chest CT scan usually delineates the extent of the bulla and shows the degree of compression of surrounding lung tissue.

IDEAL PATIENT CHARACTERISTICS AND PREOPERATIVE ASSESSMENT

The indication for intervention is defined as the presence of symptoms in a space-occupying bulla that is compressing the surrounding lung parenchyma. CT scan of the chest is the preferred imaging modality. It can show the full extent of the bulla and whether there is evidence of vascular crowding or compressed lung surrounding the bulla. Ideally, the bulla should occupy greater than one-third of the hemithorax to be suitable for resection. Pulmonary function tests indicate various degrees of obstructive disease. Those with markedly decreased forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁), or diminished diffusion capacity of the lung for carbon monoxide (D_LCO) with evidence of hypoxemia and hypercarbia are at an increased risk for perioperative complications as well as lack of improvement or even worse outcome with resection. The ideal patient for surgery is young, has normal cardiac function and only minimally diminished pulmonary function, and is still quite functional despite the dyspnea. Clearly, such patients have several options available, and bullectomy by means of video-assisted thoracic surgery (VATS) may be the most appropriate procedure. The Monaldi procedure may not be the best option for patients with other comorbidities, end-stage lung disease, deep extension of the bulla to the hilum, or inability to tolerate complications that may occur with resection.

MONALDI TECHNIQUE

The Brompton group provides the best description of this technique.³ The procedure begins with planning of the incisions based on the preoperative chest CT scan (Fig. 88-1). The incision is placed where the bulla comes closest to the chest wall (Fig. 88-2), provided that it is not at an awkward place, that is, over the scapula or so far posteriorly that it would interfere with chest tube placement. The operation is performed in the OR with general anesthesia. The patient is positioned to optimize access to the planned incisions. A small VATS-type incision is made at the predetermined site. The underlying rib is resected. The visceral pleura is entered, and purse-string sutures are placed on the visceral pleura (Fig. 88-3). Any septations present inside the bulla are divided to ensure free drainage of the entire bulla. Two drains are used in this procedure: A 32F Foley catheter is placed inside the bullous cavity, and a chest tube is placed in the pleural space (Fig. 88-4). Talc is insufflated into both the bullous cavity and intrapleural space to enhance pleural apposition and symphysis. The chest tube is placed on suction, and the Foley catheter is placed on water seal. The incisions are closed in a standard manner.

POSTOPERATIVE CARE

The postoperative care of these patients is similar to that provided to any patient with poor pulmonary function. Specifically, postoperative care begins in the preoperative period with enrollment in and completion of a pulmonary rehabilitation program and smoking cessation. In the immediate postoperative period, the pleural chest tube is removed after the leak stops and the drainage is low. The Foley catheter is removed after a week of drainage. Bronchodilators, chest physiotherapy, early ambulation, and pain control are crucial.

PROCEDURE-SPECIFIC COMPLICATIONS

Complications specific to bullectomy are similar to those for lung volume-reduction surgery or pulmonary resection in the setting of poor pulmonary function. Pneumonias, prolonged air leaks, and difficulty managing and clearing secretions are the typical complications of this group of patients. The Brompton experience, which is the largest single-institution series in the modern era, reports a mortality rate of 6.9% in 58 patients.³ These data underscore the poor pulmonary function of these patients.

SUMMARY

Although the Monaldi procedure may be an option for patients who have end-stage lung disease, bullous compressive pathology or bullae that extend to the hilum may render the resection technically difficult or impossible. For patients who can undergo this procedure, the perioperative management is similar to that for other end-stage lung disease patients who undergo thoracic procedures, with particular attention to early ambulation and management of pain and secretions.

EDITOR'S COMMENT

Because most giant bullae are not the pressurized result of "gas trapping," but rather the result of destroyed and hypercompliant lung parenchyma, there is little benefit to tube drainage. A notable exception is the presence of a lung abscess or infected bulla. Nonetheless, a feature of the Monaldi procedure that can be applied to other thoracic surgical problems is the creation of a functional pleuro-cutaneous fistula. As suggested by the Monaldi procedure, symphysis of the surrounding pleura is the important step that permits the management of air leaks with a soft catheter or even without a tube.

–SJM

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