Diagnostic Anterior Mediastinotomy

Transcription

1 Diagnostic Anterior Mediastinotomy Thomas M. McNeill, M.D., and J. Maxwell Chamberlain, M.D. P athological lesions situated in the anterior and superior mediastinum, in the pulmonary hili, or in the adjacent lung parenchyma usually are subject to a positive histological diagnosis by such techniques as endoscopic biopsy, extrathoracic lymph node biopsy, cytological studies, or by major thoracotomy with definitive excision. Whenever such lesions are believed to be surgically incurable, a major thoracotomy should be avoided if possible. Intelligent therapeutic management of these patients should be based upon a positive tissue diagnosis, and anterior mediastinotomy provides a simple, safe, rapid surgical solution. The literature on anterior mediastinotomy ranges from the classic finding of Virchow s sentinal gland and Rouvier s plotting of lymphatic drainage of the lungs to a 965 report on lung biopsy performed through the bronchoscope [l]. Recent key contributions are listed in the references [l-73. MEDIASTINO TOMY TECHNIQUE Anterior mediastinotomy for biopsy purposes can be performed using local anesthesia, but general anesthesia with endotracheal intubation is preferable for both patient and surgeon. If the bronchoscopic observation is negative the mediastinotomy can be done immediately under the same general anesthesia. The head of the operating table is elevated about 5 degrees or until the manubrium is horizontal. A transverse incision about 6 cm. in length is made over the second costal cartilage, and the entire cartilage is removed. The perichondrium is carefully preserved. The internal mammary vessels are ligated and divided. The retrosternal extrapleural space is entered in the midline by gentle dissection, deflecting the lung and mediastinal pleura laterally to avoid opening the pleural cavity. Electrocoagulation is very helpful in preserving normal tissue appearance; it permits meticulous hemostasis throughout the operation. Good From the Department of Surgery, The Roosevelt Hospital, New York, N.Y. Presented at the Second Annual Meeting of The Society of Thoracic Surgeons, Denver, Colo., Jan. 4-6, THE ANNALS OF THORACIC SURGERY

2 Anterior Mediastinotomy FIG.. Horizontal section of the thorax at the level of the second costal cartilage, viewed from below. The th mus gland sometimes is encountered first. The second costal cartilage on the rig x t has been excised and the pleura retracted laterally to provide access to lymph nodes near the superior vena cava and the trachea. visualization of the structures deep in the mediastinurn demands powerful headlamp illumination and a deep, narrow retractor. On the right side, lymph nodes at the hilum or along the superior vena cava and trachea are easily obtained and may be studied immediately by frozen section. On the left side, the hilar, paratracheal, and subaortic nodes are available for excision (Fig. ). Mediastinal tumors independent of the lung or extensions of carcinoma from the lung into the mediastinum may be exposed and biopsied. In appropriate cases (see below) the mediastinal pleura is opened, and direct lung biopsy is done. In this event, a drainage catheter is brought out through a small adjacent stab wound for overnight intrapleural suction. If the pleural cavity is entered inadvertently and the lung is not biopsied, the catheter is brought out through the closed wound and the pleural space is obliterated by simultaneously applying positive endotracheal pressure and catheter aspiration. The catheter is then withdrawn. The wound is closed in anatomical layers with special attention to closure of the perichondrium to prevent paradoxical movement or herniation of the lung. INDICATIONS, CASE MATERIAL, AND RESULTS Indications for anterior mediastinotomy are found chiefly in cases of suspected bronchogenic carcinoma which are considered to be non- VOL., NO. 4, JULY,

3 McNEILL AND CHAMBERLAIN TABLE. OPERATIVE INDICATIONS FOR DIAGNOSTIC ANTERIOR MEDIASTINOTOMY Bilateral mediastinal and/or hilar pathology Bilateral diffuse parenchymal pathology Contralateral parenchymal and mediastinal pathology Enormous mediastinal tumors Preresection tissue confirmation Preradiation or precytotoxic drug tissue confirmation Postresection second look Refused resection Total No. of Cases resectable because of mediastinal extension or poor general physical condition and in which positive tissue diagnosis is lacking. Less frequently there is a variety of bilateral mediastinal, hilar, and parenchymal lesions which may defy tissue diagnosis by conventional biopsy techniques short of thoracotomy. This includes the various granulomatoses, lymphomas, metastatic carcinomas, and others. A definite diagnosis should be established in these situations before specific therapy is recommended and so that the patient and his family may be offered an accurate prognosis. Radiotherapists usually demand tissue confirmation before starting radiation therapy, for these reasons and for academic and medico-legal reasons as well. Operative indications encountered in our series of 44 consecutive cases done between 956 and 965 are listed in Table, and the major A. B. C. D. E. FIG.. Diagram depicting the major pathological indications for mediastinotomy: (A) bilateral hilar andlor mediastinal, (B) bilateral fmrenchymal, diffuse, (C) bilateral hilar and parenchymal, (D) contralateral hilar and parenchymal, and (E) enormous mediastinal tumors. 534 THE ANNALS OF THORACIC SURGERY

4 Anterior Mediastinotomy TABLE. DIAGNOSES ESTABLISHED BY ANTERIOR MEDIASTINOTOMY IN 44 CONSECUTIVE CASES Tissue Diagnosis Node Lung Tumor Total Bronchogenic carcinoma Hyperplastic nodes Carcinoma, bilateral, diffuse, primary unknown Breast carcinoma, metastatic Hodgkin s disease Boeck s sarcoidosis Sarcoma Thymoma Eosinophilic granuloma Interstitial pulmonary fibrosis Tuberculous adenopathy Hypernephroma, metastatic Neurilemmoma Total Palpated only groups are illustrated in Figure by drawings of representative chest x-rays. Table lists the diagnoses obtained by mediastinotomy biopsy in the 44 cases, details of which are described below. The largest diagnostic group was cases of bronchogenic carcinoma, 9 of which yielded a positive tissue diagnosis. In instance the carcinoma was seen and palpated on the pulmonary artery but was not biopsied because of possible hemorrhage. Radiation therapy had been recommended for this patient because of suspected systemic spread, which was later confirmed. Mediastinal lymph nodes in additional cases of bronchogenic carcinoma showed only hyperplasia. In of these direct lung biopsy also was negative, but three months later the lobe was removed and carcinoma was indeed present. In the other, carcinoma was proved at autopsy four months later. His generally poor condition when first seen precluded thoracotomy. Multiple frozen-section examinations were obtained during the exploration, but none had been positive. Mediastinal lymph node hyperplasia was the diagnosis also in the case of a physician who five years earlier had had a right pneumonectomy performed for bronchogenic carcinoma. He returned with phlebitis and lymphedema of the left arm, and recurrence of carcinoma was suspected. Scalene, supraclavicular, and axillary lymph node biopsies were negative. Anterior mediastinotomy yielded hyperplastic lymph nodes in this second-look operation, and his complete recovery for several years has been reassuring that no carcinoma is present. 8 la VOL., NO. 4, JULY,

5 McNEILL AND CHAMBERLAIN The fourth case in which only hyperplastic nodes were obtained from the mediastinum involved a patient who had refused left upper lobectomy for what was believed to be bronchogenic carcinoma. He consented, however, to have the diagnostic anterior mediastinotomy procedure performed. Mediastinal nodes and lung biopsy showed no carcinoma. Resolution of the left upper lobe process was complete radiographically in three months. The fifth patient with lymph node hyperplasia was referred for evaluation of bilateral hilar adenopathy and diffuse infiltration in both lungs with no tissue diagnosis obtained after bronchoscopic biopsy, bilateral scalene lymph node biopsies, or numerous sputum cytological examinations. Cytotoxic drug therapy had been recommended. He was treated first for signs of congestive heart failure, and there was considerable symptomatic improvement. However, the x-ray changes persisted, and after one week diagnostic anterior mediastinotomy was done. Mediastinal lymph nodes and lung biopsy showed no carcinoma. Gradual clearing of the lung and hilar shadows suggested that congestive heart failure was the correct and only diagnosis. Metastatic carcinoma in both lungs was diagnosed in 3 patients. Gastrointestinal studies, pyelography, bone survey films, endoscopy, and scalene lymph node biopsies had all been negative in this group. Mediastinal lymph node biopsy was positive in case, and lung biopsy provided the answer in the other. The primary lesion remained obscure in all 3. Breast carcinoma metastatic to mediastinal lymph nodes was encountered twice, Hodgkin s disease three times, and Boeck s sarcoidosis by biopsy of lung nodules twice. In all of these, regional extrathoracic lymph node biopsy had first been negative. Sarcoma was diagnosed twice by conservative anterior mediastinotomy biopsy. Both were enormous tumors which were obviously not resectable. The thymoma also was enormous, half filled the thorax, and partially obstructed the superior and inferior vena cava; it disappeared after cobalt radiation therapy and has not recurred in five years. Diffuse parenchymal disease was identified by lung biopsy in a case of eosinophilic granuloma and in a case of idiopathic interstitial pulmonary fibrosis. Tuberculous hilar lymphadenopathy was confirmed histologically in patients. One of these had obvious lung cancer with mediastinal extension in the opposite lung, and biopsy was done to determine the necessary field of mediastinal radiation therapy. Metastatic hypernephroma in the posterior mediastinum was confirmed in case four years following nephrectomy. The neurilemmoma caused pain in the right arm of an elderly, obese man with hypertension and severe emphysema. Radiographically the tumor was a dense opacification above the first rib. Radiation 536 THE ANNALS OF THORACIC SURGERY

6 Anterior Mediastinotomy therapy had been recommended, but preliminary biopsy was advised because of the uncertain nature of the lesion. During exploration through the bed of the resected second costal cartilage, the apex of the lung was retracted and bullae were ruptured. The tumor was biopsied without difficulty. Prolonged pleural drainage became necessary because of a slow but persistent air leak, and extensive subcutaneous emphysema developed. The anterior approach to this posterior tumor, which occurred in a barrel-chested emphysematous patient, was cumbersome and therefore is not recommended. Diagnostic anterior mediastinotomy has been performed only in the presence of obvious mediastinal or pulmonary pathology or both. We have not performed this operation to evaluate for resection patients with obvious bronchogenic carcinoma since these usually can be managed by extended resection techniques and should be given this opportunity for curative resection by formal thoracotomy. COMPLICA TIONS Potential complications of diagnostic anterior mediastinotomy include hemorrhage, wound infection, pneumothorax, and complications attendant upon injury to any of the mediastinal structures accessible through this approach, such as the phrenic and vagus nerves, the thoracic duct, and the major arteries and veins. Three complications were actually encountered in our series of 44 consecutive cases. Pneumothorax and prolonged subcutaneous emphysema occurred once, this case also being the one instance of improper choice of operation (neurilemmoma). Wound infection occurred twice, once in an uncontrolled diabetic who had metastatic hypernephroma in the mediastinum and once in an emphysematous, debilitated patient with a large, necrotic mediastinal extension of bronchogenic carcinoma. Both responded well to open drainage through the original incision. COMMENT The proposed operation was designed to fill a gap in our diagnostic armamentarium between such minor surgical procedures as endoscopic and scalene lymph node biopsy and the extensive undertaking of exploratory thoracotomy. Previously described methods of diagnostic exploration of the mediastinum, such as retrosternal endoscopy and cervical mediastinotomy, have great merit provided the operating surgeon is experienced in the technique and is aware of the anatomical hazards and limitations of performing a biopsy or controlling hemorrhage at a distance beyond the reach of his fingers and instruments. In contrast, the hazards of extrapleural, direct-vision mediastinotomy as

7 McNEILL AND CHAMBERLAIN described are under complete control by any competent thoracic surgeon. Furthermore, lung biopsy and excision of tissues posterior to the superior vena cava and beneath the arch of the aorta, accessible by the anterior mediastinotomy route, are beyond the reach of the retrosternal endoscopic procedures. Instruments should be available for emergency thoracotomy, but to date their use has not been necessary. Exploratory thoracotomy is a formidable and inappropriate procedure when undertaken to obtain a tissue diagnosis or to evaluate for resection far-advanced disease in poor-risk patients. Rarely can such patients be grateful for what has been done for them, and indeed they often associate the beginning of their difficulties to the thoracotomy itself. In the past few years we have used diagnostic anterior mediastinotomy with increasing frequency in conjunction with preresection cobalt radiation therapy. This choice of management permits the surgeon to delay his recommendation for thoracotomy in borderline situations, which may well be clarified by the passage of a few months and the response to radiotherapy. SUMMARY A simple surgical technique has been devised to reach through a small incision pathological lesions situated in the mediastinum or at the hilum of the lung extrapleurally. Mediastinotomy performed through the bed of the second costal cartilage allows safe access to anterior and superior mediastinal, paratracheal, parabronchial, and paraesophageal lymph nodes or tumors, and if necessary, to direct lung biopsy. Proper retraction and powerful head-lamp illumination are essential for adequate exposure, and electrocoagulation is necessary for safe hemostasis. Indications for this operation are found most often among cases of nonresectable bronchogenic carcinoma or instances of puzzling pulmonary problems which lack tissue confirmation by standard biopsy techniques short of major thoracotomy. Institution of specific therapy for such patients usually awaits tissue confirmation, and this direct and simple surgical approach is most appropriate for their needs. Experience with this operation develops a facility in dissection that exposes a surprisingly wide view of mediastinal structures and pathological lesions. Operative morbidity is minimal, and the patient usually leaves the hospital in one day, occasionally two. REFERENCES. Andersen, H. A., Fontana, R. S., and Harrison, E. G., Jr. Transbronchoscopic lung biopsy in diffuse pulmonary disease. Dis. Chest 48~87, THE ANNALS OF THORACIC SURGERY

8 Anterior Mediastinotomy. Carlens, E. Mediastinotomy: A method for inspection and tissue biopsy in the superior mediastinum. Dis. Chest 36:343, Daniels, A. C. Method of biopsy useful in diagnosing certain intrathoracic diseases. Dis. Chest 6:36, Harken, D. E., Black, H., Clauss, R., and Farrand, R. A simple cervicomediastinal exploration for tissue diagnosis of intrathoracic disease with comments on the recognition of inoperable carcinoma of the lung. New Eng. J. Med. 5:4, Morgan, S. W., and Scott, S. M. A critical reappraisal of scalene fat pad biopsies. J. Thorac. Surg. 43:548, Reed, W. A. Subscalene biopsy in intrathoracic diseases. Dis. Chest 48:5, Steele, J. D., and Marable, S. A. Cervical mediastinotomy for biopsy. J. Thorac. Surg. 37:6, 959. DISCUSSION DR. JOSEPH M. ST. VILLE (Chicago, Ill.): I rise in behalf of Dr. Edward M. Goldberg, who has done a considerable number of mediastinoscopies at our hospital. His is a mediastinal diagnostic procedure using a somewhat different approach than the one described by Dr. McNeill. A small transverse cervical incision is made in the suprasternal notch. The strap muscles are separated and the pretracheal fascia is entered. A plane of cleavage is developed along the anterior surface of the trachea, and a mediastinoscope is introduced, thus visualizing the trachea and carina, the right and left main bronchi, the right upper lobe bronchus, the aortic arch, the innominate artery, the pulmonary arteries, and the esophagus from the neck to the level of the carina. Lymph nodes or other masses adjacent to these structures are well defined and easily excised or biopsied. Dr. Goldberg has now performed over 5 such procedures. He has had no mortality or serious morbidity. Two cases lost approximately 75 cc. of blood from the azygos vein. The bleeding was easily controlled by tamponade pressure. Two cases developed left recurrent nerve paresis with full recovery. This procedure has proved to be a direct and safe approach to the mediastinum in establishing diagnoses in a wide variety of pulmonary and mediastinal lesions. It has helped significantly to establish the extent of unilateral or bilateral spread of these lesions so that appropriate surgery, irradiation, or drug therapy can be initiated. DR. PETER PARNASSA (Brooklyn, N.Y.): Following the lead of the authors, we have performed the procedure through the bed of the second costal cartilage in instances with death. In 3 cases it was necessary to biopsy the lung to eutablish the diagnoses of interstitial pulmonary fibrosis and silicosis. The death that occurred was in a 7-year-old man with extensive carcinomatous invasion of the mediastinum who developed ventricular tachycardia on the fourth postoperative day. DR. DONALD F. ROWLES (Palo Alto, Calif.): I used a similar method in trying to establish a tissue diagnosis by a technique with an intermediate morbidity. In approximately 5 cases my procedure has been of value only anteriorly in mediastinum, pleura, or lung. One should not try to extend i't into the middle mediastinum or posteriorly. Furthermore, the exposure is inadequate to evaluate the resectability of carcinomas. We do reinforce the idea of a limited morbidity in this limited procedure. VOL., NO. 4, JULY,