Surgery for tuberculosis
The tuberculosis organism is an obligate aerobe and it was reasoned that by preventing oxygen from entering the cavities this would be beneficial in the treatment of patients with cavitary pulmonary tuberculosis.
Surgery for tuberculosis began with collapse therapy. Various forms of collapse therapy have been used including:
-- thoracoplasty
-- wax or lucite ball plombage
-- phrenic nerve crush or interruption
-- pneumoperitoneum
-- and induced pneumothorax.
Collapse therapy continued to be the treatment of choice for tuberculosis infections until chemotherapy with streptomycin and para-aminosalicylic acid (PAS) was introduced in 1945. It was not until the introduction of isoniazid in 1952 that prolonged cures could be obtained with antibiotic therapy.
Gradually resectional surgery replaced collapse therapy as the primary surgical approach to patients with tuberculosis infections having residual destroyed lung or cavitary disease. With the introduction of rifampin in 1966 the need for surgery was markedly reduced and the sanatoria system gradually became extinct
Drug-sensitive tuberculosis in almost all instances can be cured with antibiotic therapy alone. The standard treatment of drug-sensitive tuberculosis is with INH and rifampin and a short course of pyrazinamide.
Patients with drug-sensitive tuberculosis are only operated on for complications such as:
--to rule out the presence of cancer;
--massive hemoptysis (>600 cc in 24 hours);
--brochostenosis ,bronchoectasis
--bronchopleural fistula
--decortication of a trapped lung, which occurs when polymicrobial contamination occurs within the pleural cavity in tuberculosis patients who have had a pleural effusion.
Patients having tuberculosis whose organism is resistant to both INH and rifampin are classified as having MDRTB and present a greater challenge to the surgeon. Often there is resistance to the three other first-line drugs; ethambutol, streptomycin, pyrazinamide, and many of these patients are also resistant to a number of the second-line drugs.
MDRTB Patients are operated on for:
-- the indications as previously noted for patients with drug-sensitive tuberculosis -- persistent cavitary disease with or without a positive sputum -- destroyed lobe, or destroyed lung with or without a positive sputum.
In the United States today, patients with MDR-TB make up the largest group of patients operated on for pulmonary infections with tuberculosis
Preparation for surgery is an important part of the therapeutic approach for patients with mycobacterial infections.
--The most important aspect of preparation is nutrition.
--Patients with albumin <3.0 g/dl are not operated upon.
--Nutritional supplementation is accomplished either orally or by gastrostomy or jejunostomy feeding tubes to improve anabolic state before surgery.
--The best available antibiotic therapy is given for approximately 3 months prior to surgery. In MDR-TB only about half the patients have negative sputum prior to surgery.
--Routine evaluation, as with other pulmonary surgery, includes pulmonary function tests, ventilation perfusion scans, and computed tomography.
Surgical principles include: -- leaving enough viable lung tissue to have a functional postoperative patient. --- Double lumen tubes or bronchial-blockers are used in all operations.
-- All grossly involved lung, which includes cavitary disease and destroyed lung should be removed, while nodular disease remaining in other parts of the lung can be left behind. -- Fluid administration during surgery is kept to below 1200 cc whenever possible and with pneumonectomies below 800 cc
-- The muscle flaps
- latissimus dorsi muscle
-intercostal muscle
are used to:
-decrease bronchopleural fistula
-fill space
In cases:
pneumonectomy
polymicrobial contamination
positive sputum at the time of surgery.
-- Omental flaps are also used in case of :
- massive contamination
-previous surgery
-extreme cachexia
--If there is massive contamination , the chest is left open (Eloesser procedure) it is packed with half strength Dakin’s solution using Kerlix gauze and changed on a daily basis for 5–6 weeks. When the opening is closed, assuming the intrathoracic chest wall is clean, Claggets solution is left in the pleural cavity.
-- Pleural tents have been suggested to help eliminate space and seal air leaks. This is not practical in mycobacterial surgery because most of the dissections over the upper lobe are done in extrapleural plane.
-- Appropriate antibiotic therapy is continued postoperatively
--Operative mortality in experienced hands should be less than 5%.
Complications
25–30% (but with experience this can be brought down to less than 15%). -- Bronchopleural fistula
most often occurring after right pneumonectomy
20% without muscle or omental buttress.
-- Wound infection and abscesses are common
-- Apical space
-- Other complications such as air leaks, bleeding, and postpneumonectomy pulmonary edema are similar to other thoracic procedures for nonmycobacterial disease.