Pleural & Pericardial surgeries

Decortication is a procedure involving the surgical removal of the surface layer, membrane, or fibrous cover of LUNGS. The procedure is usually performed when the lung is covered by a thick, inelastic pleural peel restricting lung expansion.

Decortication is performed under general anaesthesia. It is a major thoracic operation requiring a full thoracotomy. Now this procedure can also be performed using thoracoscopy/ VATS. All fibrous tissue is removed from the visceral pleural peel and pus is subsequently drained from the pleural space.

Decortication is a surgical procedure that removes a restrictive layer of fibrous tissue overlying the lung, chest wall, and diaphragm. The aim of decortication is to remove this layer and allow the lung to reexpand. When the peel is removed, compliance in the chest wall returns, the lung is able to expand and deflate, and patient symptoms improve rapidly.

In most people, the pleural space is less than 1 mm thick. When this space is violated by any number of pathological disorders, the distribution of certain cells and fluid can be altered, with serious medical consequences. One common pathological process that affects the pleural space is fibrothorax, which is an abnormal accumulation of fibrous tissues over the lung or visceral pleura. The fibrous tissues that deposit over the lung parenchyma can be so intense that the underlying lung fails to expand. Over time, the lung becomes entrapped or encased. 

Although decortication is an effective surgical procedure for this condition, its success depends on careful selection of patients. As in all thoracic surgery procedures, the preoperative workup should be thorough and the surgery should be done at a particular timed interval. Moreover, the surgeon should also be technically skilled at entering the chest and removing the peel.

Indications

The primary indication for decortication in a patient with fibrothorax is presence of symptoms due to lung restriction resulting from development of a thick fibrinous peel. The timing of surgery is vital for success. In many cases, the peel may spontaneously resolve and the symptoms may subside. Most surgeons will perform a decortication for the following conditions:

  • The pleural peel has been present for more than 4-6 weeks
  • Lung symptoms are disabling
  • There is radiological evidence of a trapped lung
  • Decortication is frequently necessary when other minor interventions (eg, chest tube) have not resulted in clearance of the infection or hemothorax. Tuberculous empyema is usually first treated with drugs and decortication is only undertaken after long-term drug therapy fails.

Contraindications

  • Other than the physiological fitness of the patient, there are no absolute contraindications to decortication. In some patients who also have underlying lung disease, removal of the peel may not help the lung expand and thus surgery would be futile.
  • Other conditions that may make decortication futile include the presence of a pleural space infection and large airway stenosis. In such cases, the lung will not expand to fill the pleural space. A more extensive pneumonectomy may be the only option, but only if the patient has been worked up preoperatively. Pneumonectomy is a major undertaking with a very high mortality& morbidity.
  • Decortication may not be possible in presence of uncontrolled lung infection or contralateral lung disease, or for a chronically debilitated patient. Medical optimization may be required prior to undertaking surgery in these patients. Ideally, the patient’s nutritional status should first be normalized (with nasogastric feedings if necessary) and sepsis should be controlled with appropriate antibiotic therapy.
  • Other relative contraindications include coagulopathy, severe chest wall infection, and terminal disease.

Technical Considerations

  • Decortication gives the best results in patients who seek early treatment. Fibrothorax is a time-dependent process and can be prevented. Depending on the cause, insertion of a chest tube to remove an effusion or hemothorax may prevent the development of fibrothorax.
  • Among patients with chest trauma who suffer a hemothorax, placement of a chest tube and complete drainage usually prevents development of fibrothorax. Numerous studies have shown that early and complete evacuation of clotted hemothorax and parapneumonic effusions leads to decreased morbidity and mortality.
  • Some of the reasons that may explain an incomplete return of lung volume include elevation of the diaphragm, mediastinal shift, intercostal muscle fibrosis, or decrease in size of the thoracic cavity. Some experts believe that the longer the empyema is allowed to progress, the less the likelihood that lung function will return back to normal. Although some authors report an association between shorter course of disease and improved outcomes, this is not a universal finding among all surgeons.
  • Even though no studies have been done to explain failure of the lung to expand after so-called successful decortication, the most likely reason is either technical difficulties or incomplete removal of the peel. In many cases, the plane of dissection can be difficult. Too much persistence in removing the thin peel can also injure the underlying lung parenchyma and result in massive air leaks.
  • Inability to define the plane of dissection between the peel and the visceral pleura is an especially troublesome technical challenge that can adversely affect results. If visceral pleurectomy is performed, air leakage and postoperative hemorrhage may compromise pulmonary function. Care must be taken throughout the operation to protect the phrenic nerve from injury; fortunately, this usually is not an issue, because the mediastinal pleura is rarely involved in the inflammatory process. Incomplete parietal pleurectomy or inability to free the diaphragm may also compromise results.
  • If patients are appropriately selected, complete reexpansion of the lung after decortication can usually be achieved. Occasionally, however, an issue related to residual pleural space might arise after an otherwise technically satisfactory decortication. If this space is not obliterated, failure is inevitable.

Outcomes

  • The results after decortication are often fruitful. The morbidity and mortality after a decortication is dependent on the patient age, underlying comorbidities, and development of complications from the surgery. Decortication in general has an excellent outcome in young people.
  • In younger patients with benign causes of fibrothorax, the outcome is excellent and quality of life is much improved.Most patients begin to feel relief of symptoms soon after surgery. In elderly patients with multiple comorbidities, recovery is often slow but symptom relief is also better. The majority of patients regain their previous exercise endurance and are able to return back to their original work.
  • However, when the procedure is done in patients with compromised lung function, the morbidity can be high. Besides surgery itself, the thoracic incision and general anesthesiaalso carry a high morbidity in people with no lung reserve. Old data suggest that the overall mortality in healthy people is less than 1% but may run as high as 4-6% in individuals with underlying lung disease. However with video-assisted thoracoscopic surgery (VATs), the current mortality rates are slightly lower.
  • To avoid complications, the surgeon has to pay attention to detail. The peel should be removed with great care and injury to nearby organs should be avoided. If the decortication is done adequately, lung function improvement is remarkable. However, the ultimate return of lung function depends on preoperative lung disease.
  • If the lung parenchyma was normal prior to surgery, then complete reexpansion of the lung and obliteration of the pleural space is certainly possible. In most cases, lung volumes improve after decortication, but it is rare to see return to preoperative values.

Anatomic Considerations

  • The boundaries of the pleural space are the visceral pleura, which envelops the lungs, and the parietal pleura, which is the inner lining of the thoracic cavity.The goal of decortication is to remove all the fibrinous peel and necrotic tissue, and help the lung reexpand and equally important not to leave any residual air spaces.
  • The two most common problems encountered when performing decortication are a pleural cavity infection and fibrosis.It is difficult for the underlying lung to expand when there is a thick peel overlying the parenchyma. Consequently, there is a large residual space left in the chest cavity that almost always gets infected. Therefore, for the surgeon to have good success with decortication, timing of surgery is crucial.
  • If the disease has been chronic, the rib spaces are often fused and the chest cavity is severely constricted. Entry into the chest can be very difficult. If the peel is very thick and adherent, injury to the lung parenchyma can occur with moderate air leak. If the lung has an inherent disorder, the possibility of reexpansion may not occur. Finally, decortication is not a trivial procedure and can be very bloody; thus, the patient must also be physiological fit to undergo the procedure. All these factors must be considered when planning a decortication.
  • Moreover, once inside the chest cavity, no lung may initially be visible because of the thick fibrous peel. The peel can vary in thickness from a few millimeters to few centimeters. One may also find necrotic debris and abscess along the chest cavity. It is important to avoid dissection along the medial border of the lung because the heart chambers are close by. The dissection should be started on lateral aspects or near the fissures. In most cases, the lower lobe is fused with the diaphragm and one can easily enter the abdominal cavity if the dissection is too deep.
  • For safe decortication, the chest cavity is best entered at the 5th/6th intercostal space and dissection should be started where the peel is the thinnest and easily removed. It is important to reassess the anatomy every few minutes to prevent injury to the organs. Blind digital peeling should be avoided, especially near the apex of the lung. This area is best approached when the upper lobe can be retracted inferiorly and the lung apex is visible. Severe bleeding from injury to the subclavian vessels and pulmonary artery has been reported.
  • Because extensive decortication or radical pleurectomy can be associated with air leaks, methods have been described to reconstruct the diaphragm to help lower the incidence of postoperative complications.
  • When performing a VATS procedure, one must be aware of the adjacent structures to avoid injury. On the superior aspect, the subclavian vessels can be found lying deep to the pleura but clearly visible. Along the medial border, one may come across the thymus, trachea, heart, phrenic nerve, aorta (on right), vena cava (on left), and the esophagus (posteriorly). In the posterolateral chest, one may come across the sympathetic chain, azygous vein, and the diaphragm (inferiorly).

Pericardial Window- VATS

Pericardial window is used diagnostically and, more often, therapeutically for drainage of accumulated pericardial fluid (a condition that most often occurs after cardiac surgery but has many other possible causes). The pericardium envelops the heart like a cocoon; its cardiac filling can be impaired when this cavity fills with excess fluid. When the limited space between the noncompliant pericardium and heart is acutely filled with blood or fluid, cardiac compression and tamponade may result. Pericardial window in combination with systemic chemotherapy may also prevent accumulation of large fluid volumes in patients with neoplastic pericardial disease. 

Pericardial window involves the excision of a portion of the pericardium, which allows the effusion to drain continuously into the peritoneum or chest.  The fluid can be drained in any of 3 ways: via a small subxiphoid incision, thoracoscopically, or via a thoracotomy. 

Indications

The following are indications for a pericardial window  :

  • Symptomatic pericardial effusions
  • Asymptomatic pericardial effusions that warrant a pericardial window for diagnosis
  • Hemodynamically stable patients with an undiagnosed pericardial effusion (a thoracoscopic approach is ideal)
  • Coexisting pericardial, pleural, or pulmonary pathology that requires diagnosis or therapy (a thoracoscopic approach is ideal)
  • Known benign effusions that reaccumulate after aspiration
  • Drainage of a purulent pericardial effusion
  • Early fungal or tuberculous pericarditis in which resection of the pericardium is required to prevent future pericardial constriction
  • Use as part of the mediastinal debridement, in patients with descending mediastinitis
  • Loculated effusions situated unilaterally or posteriorly (more easily approached thoracoscopically)
  • Chylopericardium (thoracoscopic window and ligation of the thoracic duct)
  • Delayed hemopericardium or effusions after cardiac surgery (usually treated via a subxiphoid approach, but a thoracoscopic approach is also used)
  • An effusion in a patient with a substernal gastric or colonic conduit in whom a subxiphoid approach is not possible (an unusual indication for a thoracoscopic pericardial window)

Contraindications

The following is a contraindication for a pericardial window  

  • Concomitant cardiac surgery necessitating a sternotomy for which a full pericardiotomy would be performed

Technical Considerations

The following technical points may improve the performance of pericardial window procedures:

  • If the patient is unstable, employ the subxiphoid approach
  • Use the Allis clamp to grasp the pericardium
  • Resect an adequate area of pericardium
  • Ensure that no undrained areas of the pericardial space remain by using a sucker to explore all areas.