of Pulmonary Decortication

Transcription

1 Physiological Evaluation of Results of Pulmonary Decortication Jeremy R. Morton, M.D., Samuel F. Boushy, M.D., and Gene A. Guinn, M.D. A reasona aggressive surgical approach to the treatment of trapped lung associated with a fibrous rind has proved rewarding [l, 6, 9, 113. Prolonged sepsis associated with empyema is replaced by a.ble prospect of rapid recovery following expansion of the lung to fill the fluid-filled space. mprovement in pulmonary function also may follow decortication, but the extent and rapidity of recovery have proved difficult to predict. Studies by others [Z-5, 101 have demonstrated that absence of underlying parenchymal disease is the best assurance that there will be significant improvement in pulmonary function after operation. MATERALS AND METHODS A total of 141 cases involving lung decortication have been seen at the Houston Veterans Administration Hospital over a 16-year period and are reported here. ncluded in this group are 17 patients who underwent decortication only, and in whom ventilatory studies were performed before and after operation, and 1 patient who underwent decortication in whom pulmonary arteriography was done before and after operation. The causes of trapped lung in our series were classified into three categories occurring with about equal frequency: hemothorax, tuberculous empyema, and a miscellaneous group largely represented by nontuberculous infections resulting from lung disease. The distribution of cases among these categories is presented in the table. The 43 patients with hemothorax included 31 with penetrating injuries and 12 with blunt trauma. A mean interval of 14 days elapsed between injury and thoracotomy for decortication. The 46 patients with tuberculosis were hospitalized longer before decortication and invariably had underlying parenchymal disease, although in many instances it was not extensive. n the group with miscellaneous infections, largely represented by nontuberculous empyema, 52 patients had decortication. Antecedent pulmonary infection had occurred in 34 patients of this group. Less common causes were spontaneous pneumothorax, ruptarecl amoebic liver abscesses, and pulmonary fungal infections. From the Cora and Webb Mading Department of Surgery, Baylor College of Mcdicine, and the Surgical Service and Pulmonary Function Laboratory, Veterans Administration Hospital, Houston, Tex. Presented at the Sixteenth Annual Meeting of the Southern Thoracic Surgical Association, Washington, D.C., Nov , Address reprint requests to Dr. Guinn, Veterans Administration Hospital, 2002 Holcombe Boulevard, Houston, Tex VOL. 9, NO. 4, APRL,

2 MORTON, BOUSHY, AND GUNN CAUSES OF DSEASE N 141 PATENTS WHO UNDERWENT LUNG DECORTCATON No. of Cause of Disease Patients Trauma (hemothorax) 43 Penetrating 31 Nonpenetrating 12 Tuberculous infection 46 Empyema associated with parenchymal disease 31 Postoperative complication 11 Unexpanded lung from therapeutic pneumothorax 4 Nontuberculous infection 52 Antecedent pulmonary infection 34 Associated with ruptured bullae 10 Ruptured liver abscess 3 Fungal infection 2 Neoplasm 3 Total 141 The technical details of removing the fibrous rind did not vary from those reported by others [71. Complete decortication was planned in all cases, but because of technical considerations this did not always include total removal of the rind from the chest wall and diaphragm. All cases included in this report were thought to have had an adequate decortication of the lung. Supplementary procedures were performed in 33 patients who underwent decortication. Lung resection was required in 17 patients with active parenchymal disease. Six of these 17 patients also had concomitant thoracoplasty. Three additional patients had repair of traumatic diaphragmatic hernia, 1 required pericardiectomy, and 6 required bullectomy and pleurodesis. The influence of these supplementary procedures on the recovery of pulmonary function after operation was significant; therefore, these cases have been excluded in evaluating the effects of decortication on pulmonary function. Nonfatal complications occurred in 11 patients. These complications were bronchopleural fistula in 6 patients, wound infection in 3, hemothorax in 1, and respiratory insufficiency requiring tracheostomy in 1. The final functional result was related to the occurrence of these secondary conditions. Complications resulted most often when there was parenchymal disease or when the surgical procedure was difficult from a technical standpoint. There were 5 deaths, constituting an overall operative mortality of 3.5%. Only 2 of the patients who died had undergone only decortication without associated procedures. One died of a pulmonary embolus and the other of a bleeding diathesis which probably resulted from a mismatched blood transfusion. The other 3 deaths resulted from hemorrhage, cardiac arrest, and septicemia, respectively. PHYSOLOGCAL CHANGES Pulmonary function results are presented only for those patients who underwent decortication alone or in combination with minor wedge resections, since the data on patients with associated major resections and thoracoplasties are difficult to interpret. The most striking change associated with decortication was seen, as would be expected, in the measurements of vital capacity and total lung capacity. The ratio of forced expiratory volume for one second (FEV1) to forced vital capacity, 322 THE ANNALS OF THORACC SURGERY

3 Pulmonary Decortication Vital Capacity percent of predicted normal 0 : 10 - Tbc Chronic lung disease Pyogenic infection and trauma PrWP 0 postop (months) (years) TME AFTER SURGERY FG. 1. Changes in vital capacity in 17 patients after decortication. which is a reflection of airway obstruction, did not change. Figure 1 shows the vital capacity in 17 patients before and at varying times after decortication. n all but 4 of these patients pulmonary function was improved. The patients with tuberculosis showed significantly less improvement postoperatively than did those in whom trauma or pyogenic infection was the causative agent. l ital Capacity percent of predicted normal before with 3 months after 9 months after em py ema empyema decortication decortication FG. 2. Serial vital capacity determinations in a patient who developed empyema while under observation. VOL. 9, NO. 4, APRL,

4 MORTON, BOUSHY, AND GUNN Vital Capacity percent 01 predicted normal i L months years DURATON OF PLEURAL DSEASE.~ 1.1.l.. DrmD -pos~op FG. 3. Dtiration of pleural disease and changes in vital capacity after decortication in /' patients. Our studies indicate that a patient can show a gradual improvement in lung function for a period of up to one year after decortication. One patient was studied prior to his developing a loculated empyema. The progress of his pulmonary function before empyema, with empyema, and after decortication is shown in Figure 2. The greatest improvement in lung function, as estimated by the vital capacity, occurred in patients whose illness was of short duration; however, as illustrated by Figure 3, several patients who had had trapped lung for extended periods of time improved after decortication. Where the vital capacity was normal before operation, little change was noted after decortication; this most likely indicates that the thickened pleura did not interfere significantly with the lung function. Vital Capacity O2 Uptake volume in cc volume in ccl min 1 R ooo R 1800 R 1800 R lo preop postop preop postop preop postop preop postop patient A patient B patient A patient B FG. 4. Bronchospirometry before and after decortication. 324 THE ANNALS OF THORACC SURGERY

5 Pulmonary Decortication B FG. 5. Ptrlinonal-y angiography (A) before and (B) after decoytictition, Broncliospirometry was performed in 2 patients before and after decortication. The oxygen uptake and vital capacity in these 2 patients are illustrated in Figure 4. These studies showed a relatively greater defect in oxygen uptake than in vital capacity on the involved side; also, a more striking recovery of oxygen uptake was noted after surgery. This supports the findings of others [41 that in most cases of trapped lung there is a significant decrease in pulmonary blood flow on the involved side which is reversible after decortication. A preoperative pulmonary angiogram (Fig. 5A) in a patient with trapped lung demonstrated distortion and constriction of the vessels on the involved side, with marked delay in the progress of the contrast material. A postoperative study (Fig. 5B) showed significant improvement. Dye-dilution studies performed from the right and left pulmonary arteries at the time of pulmonary arteriography confirmed the finding of decreased blood flow to the diseased side, with partial recovery of normal flow 10 days postoperatively. Savage and Fleming [81 have pointed out that recovery of the pulmonary vasculature may also be a gradual process over a period of months, as is the case in ventilatory recovery. SUMMARY A group of 141 patients who underwent lung decortication is presented. The etiology of the disease process, operative complications, and operative procedures performed concomitantly are outlined. Seventeen patients were selected for review who had decortication only and in whom preoperative and postoperative pulmonary function tests were performed. Two patients in this group had bronchospirometry : one patient had pulmonary arteriography. Our studies indicate that there is a reduction in vital capacity and pulmonary blood flow with trapped lung. Patients with pleural disease of short duration demonstrated more improvement after decortication than did those who had had thickened pleura for prolonged periods of time. Patients with significant VOL. g, NO. 4, APRL,

6 MORTON, BOUSHY, AND GUNN reduction in vital capacity preoperatively had considerable improvement after operation. When the preoperative function studies were normal, there was little change after operation. REFER EN CES 1. Ackman, F. D., and Madone, P. Decortication preceding thoracoplasty for elimination of long-standing tuberculous empyema. J. Thorac. Surg. 22: 358, Carroll, D., McClement, J., Himmelstein, A., and Cournand, A. Pulmonary function following decortication of lung. Amer. Rev. Tuberc. 63:231, Gordon, J., and Welles, E. S. Decortication in pulmonary tuberculosis including studies of respiratory physiology. J. Thorac. Surg. 18:337, Patton, W. E., Watson, T. R., Jr., and Gaensler, E. A. Pulmonary function before and at intervals after surgical decortication of lung. Surg. Gynec. Obstet. 95:477, Rudstrom, P., and Thoren, L. Decortication of lung. Acta Chir. Scand. 110:437, Samson, P. C., Burford, T. H., Brewer, L. A., 111, and Burbank, B. Management of war wounds of the chest in a base center: Role of early pulmonary decortication. J. Thoruc. Surg. 15:1, Samson, P. C., Merrill, D. L., Dugan, D. J.. Shabart, E. J., Yee, J., and Barber, L. M. Technical considerations in decortication for the pleural complications of pulmonary tuberculosis. J. Thorac. Surg. 36:43 1, Savage, T., and Fleming, H. A. Decortication of lung in tuberculous disease: Study in 43 cases. Thorax 10:293, Sellors, T. H., and Cruickshank, G. Chronic empyema. Brit. J. Surg. 38:41, Siebens, A. A., Storey, C. F., Newman, M. M., Kent, D. C., and Standard, J. E. The physiologic effects of fibrothorax and the functional results of surgical treatment. J. Thoruc. Surg. 3258, Thomas, C. P., and Cleland, W. P. Decortication in clotted and infected hemothoraces. Lancet 1 : 327, THE ANNALS OF THORACC SURGERY