Superior Vena Caval Obstruction Secondary to Fibrosing Mediastinitis

Transcription

1 Superior Vena Caval Obstruction Secondary to Fibrosing Mediastinitis Robert E. Miller, Col, MC, USA, and Francis J. Sullivan, Ph.D. ABSTRACT Eight patients with obstruction of the superior vena cava (SVC) secondary to fibrosing mediastinitis are presented. Four patients were managed without surgical reconstruction of the SVC. Of these, 2 are severely symptomatic from SVC obstruction, 1 is asymptomatic, and 1 is alive though his condition is unknown. Four patients were managed with surgical replacement of the SVC. Each is asymptomatic. One of 2 aortic homografts is occluded and the other is markedly stenosed at the cephalad suture line. A late occlusion occurred in the Teflon prosthesis. In the fourth patient, a bypass graft using composite autogenous veins was complemented with an arteriovenous fistula. Venography in this patient at one, six, and thirteen months revealed graft patency; he has no limitations in his physical activities. T he clinical manifestations of superior vena caval (SVC) obstruction secondary to fibrosing mediastinitis are the following: (1) venous distention in the head, neck, and upper extremities; (2) marked venous channels over the anterior chest and abdomen: (3) morning edema of the face and hands; and (4) headache and cyanosis that are aggravated by dependence and physical exertion. Since the insidious encroachment of fibrosing mediastinitis upon the SVC enables collateral venous channels to develop [l, 4, 6, 91, the intensity of these symptoms depends upon the abruptness and completeness of occlusion and the availability of collateral pathways. A cursory evaluation of the simple mechanical problem of SVC obstruction suggests that replacement of the vessel is the obvious surgical correction. Recent articles [3, 101 have reviewed the methods and results using synthetic and biological materials for grafting. Failure to achieve consistently successful functional and anatomical results, however, has relegated this rarely encountered problem to the continual observation category. From the Department of Surgery and Clinical Research Service, Fitzsimons General Hospital, and Physiology Division, U.S. Army Medical Research and Nutrition Laboratory, Denver, Colo. We are grateful to Gary L. Neal, Maj, George F. Schuchmann, Lt Col, and Robert L. T,reasure, Lt Col, all MC, USA, for their assistance in the management of Patient 8, and to Jerome H. Kaplan, Maj, MC, USA, for the angiographic support. Accepted for publication Dec. 4, Address reprint requests to Dr. Miller, Longmont Clinic, 1925 Mountain View Ave., Longmont, Colo

2 MILLER AND SULLIVAN The purpose of this paper is to present the experience at Fitzsimons General Hospital in the management of 8 patients with benign SVC obstruction. Patient 8, who had autogenous vein bypass grafting complemented by an arteriovenous fistula, was free from symptoms of obstruction thirteen months postoperatively. C 1 in i ca 1 Mat eria 1 The 8 patients in this series are men. Their histoplasmosis skin tests were all positive; histoplasmosis complement fixation values appear in Tables 1 and 2. Prophylactic antifungal therapy was not instituted in these patients, and clinical symptoms related to exacerbation of histoplasmosis were not seen. Patient 1. A 38-year-old man first noted enlarged venous channels of the lower anterior chest in 1952; an increase in the neck size was noted in On July 23, 1958, he was admitted for evaluation, and angiography revealed a nearly obstructed SVC with reflux into the left innominate vein and retrograde passage of contrast material into the right internal mammary vein. The patient was discharged with the presumptive diagnosis of fibrosing mediastinitis secondary to histoplasmosis. During follow-up in April, 1972, the patient admitted having frequent episodes of dizziness and syncope. Comment: We presume that the patient s symptoms are related to SVC obstruction. However, thorough evaluation is necessary to exclude other en ti ties. Patient 2. A 22-year-old man had biopsy of a right supraclavicular mass that revealed a sclerosing process similar to fibrosing mediastinitis. He was admitted on March 4, 1966, with the major complaints of a drooping right eyelid and mild exertional dyspnea of thirty months duration. A chest roentgenogram showed widening of the superior mediastinum. A vena cavagram demonstrated narrowing of the SVC. The patient was discharged with a diagnosis of persisting Horner s syndrome but was otherwise asymptomatic. In August, 1972, follow-up revealed that the patient was still free from symptoms of SVC obstruction. Comment: Moderate compromise of the SVC has not produced noticeable clinical symptoms, apparently because the fibrosing mediastinitis did not continue to progress. Patient 3. A 22-year-old man had a right upper lobe infiltrate with hilar adenopathy that was detected during routine physical examination. He was admitted on October 9, 1965, at which time venograms revealed obstruction of the right and left innominate (Fig. 1) and azygous veins. Eleven days later the patient experienced headache, syncope, and neck vein distention. A presumptive diagnosis of total occlusion of the SVC was made, and anticoagulant therapy was begun. Repeat venography was not performed. Distention of the neck gradually subsided, and the patient was 484 THE ANNALS OF THORACIC SURGERY

3 TABLE 1. BENIGN SUPERIOR VENA CAVAL OBSTRUCTION: NONRECONSTRUCTIVE MANAGEMENT Age" Date of Complement Patient (yr.) Hospitalization Fixation Diagnostic Last Follow-up Specimen Date Findings 1 38 July 1958 Unknown... April 1972 Severely symptomaticb; activity limited; unemployed 2 22 March 1966 Unknown Supra- Aug Asymptomaticb; clavicular activity normal; node employed 3 22 Oct Negative Alive but status unknown 4" 30 July : 16 Thoracotomy Aug Severely symptomaticb; "Age at time of hospitalization. brelated to SVC obstruction. "Previously reported [5]. specimen activity limited; employed

4 TABLE 2. BENIGN SUPERIOR VENA CAVAL OBSTRUCTION: RECONSTRUCTIVE MANAGEMENT Age Complement Date of Graft Postoperative Last Follow-up Patient (yr.) Fixation Operation Material Venogram & Date Date Findings :128 March 1957 Aortic homograft :32 May 1962 Teflon :32 May 1958 Aortic homograft 8 34 Negative Aug Composite autogenous vein A diagnostic specimen in each patient was obtained by thoracotomy. bage at time of operation. Previously reported [5]. Related to SVC obstruction. Graft occluded, Oct April 1957 Marked stricture April 1972 at cephalad suture line, Aug Marked stenosis Dec at cephalad suture line, April 1967 Patent Sept au tograf t, Sept Asymptomaticd; activity normal; unemployed Asymptomaticd; activity normal; employed Asymptomatic ; activity normal; employed Asymp tomaticd; activity normal; employed

5 Correctzon of Superior Vena Caval Obstruction FIG. 1. Patient 3. Posteroanterior view showing nearly obstructed SVC and totally occluded left innominate vein. discharged with no symptoms of SVC obstruction. Since then the patient has not been examined in a government hospital, but he is known to be alive. Comment: Despite total occlusion of the azygous vein and nearocclusion of the proximal portions of the right and left innominate veins, the patient was asymptomatic. We assume that the patient first experienced symptoms when the SVC became totally occluded. Either collateral development or recanalization accounted for the patient becoming asymptomatic. Patient 4. A 30-year-old man was admitted on July 19, 1955, with the major complaints of dyspnea, cough, and substernal pain. A right thoracotomy was performed on October 26 because of an enlarging right hilar mass. A large, fixed mass was found that involved the azygous vein, right upper lobe of the lung, right pulmonary artery, and SVC. Pathological examination of the pulmonary parenchyma, occluded azygous vein, and mediastinal mass was consistent with histoplasmosis. From 1956 to 1963 the patient had repeated episodes of hemoptysis necessitating hospitalization. In 1962 the first symptoms of SVC obstruction were noted. A superior vena cavagram was performed in 1964 (Fig. 2). The patient continues to have increasing symptoms from SVC obstruction. He must sleep in a fetal position with four pillows and he cannot lower his head below his waist or stand at military attention. Comment: Despite the extended period of nearly total SVC occlusion, collateral development has been inadequate. A 40-pound weight gain may be in part responsible for the increasing symptomatology. However, he has elected to tolerate these symptoms rather than undergo surgical reconstruction of the SVC. Patient 5. A 25-year-old man was admitted on March 10, 1957, with the major complaints of weakness, lethargy, and syncope that were aggravated by VOL. 15, NO. 5, MAY,

6 MILLER AND SULLIVAN FIG. 2. Patient 4. Posteroanterior view showing a prominent right internal thoracic vein. exercise. A right thoracotomy was performed two weeks later because of clinical SVC obstruction and a right mediastinal mass. A large inflammatory mass was found that totally occluded the azygous vein and nearly occluded the SVC. The SVC was replaced with an aortic homograft. However, clinical signs of SVC occlusion returred in the immediate postoperative period. Venography revealed total occlusion of the SVC. When last examined at Fitzsimons General Hospital in October, 1967, he was asymptomatic. Comment: Although clinical SVC obstruction persisted, the patient was asymptomatic. Patient 6. A 22-year-old man was admitted on May 4, 1962, with the sensation of pressure in the head and neck. A venogram revealed total occlusion of the SVC. During a mediastinal exploration eight days later for a persisting right mediastinal mass, a Teflon graft was used to bypass the obstructive fibrosing mediastinal mass. The postoperative course was uneventful. A venogram on August 6, 1962, revealed that the graft was patent but showed marked stenosis at the cephalad suture line. In May, 1963, physical examination demonstrated signs of SVC occlusion. However, the patient was asymptomatic. Comment: Clinical manifestations constituted presumptive evidence of an occluded SVC. Gradual occlusion probably allowed adequate collateral circulation to develop. Patient 7. A 42-year-old man was admitted on April 21, 1958, with an eight-month history of prominence of the veins of the head and neck. A venogram revealed occlusion of the SVC. On May 22 the SVC was reconstructed with an aortic homograft, and the phrenic nerve was transected and repaired. Pathological examination revealed fibrosing mediastinitis secondary to histoplasmosis. Venograms in 1960, 1964, and 1967 showed marked stenosis at the cephalad suture line. 488 THE ANNALS OF THORACIC SURGERY

7 Correction of Superior Vena Caval Obstruction A FIG. 3. Patient 8. (A) Preoperative posteroanterior view showing total occlusion of the superior vena caua and an enlarged right internal thoracic vein collateral. (B) Posteroanterior view thirteen months postoperatively. Comment: Despite a poor anatomical result, the patient does not manifest symptoms of SVC obstruction and engages in normal physical activities. Patient 8. A 34-year-old man first noted puffiness of the face and prominence of the anterior chest and upper abdominal veins in April, Venography revealed near-occlusion of the SVC. An exploratory thoracotomy the following February revealed fibrosing mediastinitis secondary to histoplasmosis with near-occlusion of the SVC and total occlusion of the azygous vein. During the next eighteen months he experienced increasing episodes of dizziness and syncope as well as a marked decrease in exercise tolerance. He was admitted on August 2, 1971, for elective reconstruction of the SVC. Preoperative evaluation indicated total obstruction of the SVC (Fig. 3A) and moderate obstructive pulmonary disease. However, lung compartment studies, blood gas measurements, and the coagulation screen were normal. Pressure in the innominate vein during exercise rapidly reached hypertensive levels (Table 3). This declined during an eight-minute rest period. Nine days after admission an operation was performed. Through a median sternotomy a large, ligneous mass was found that involved the left and right innominate veins and the SVC. A five-paneled cylinder 2.5 cm. in diameter and 7 cm. long fashioned from reversed saphenous vein was sutured end-to-side into the caudal segment of the left innominate vein and end-toend into the caudal segment of the SVC. A small reversed saphenous tributary was sutured between the ascending aorta and the left innominate B

8 MILLER AND SULLIVAN TABLE 3. LEFT INNOMINATE VEIN PRESSURE STUDIES IN PATIENT 8 Resting Treadmill At End of Exercise Date Pressure" Setting Time Physical Status Pressure" Aug. 10, ", 3.4 mph. 80 sec. Paroxysmal 85 (preop.) coughing Sept. 8, ZOO, 3.4 mph. 20 min. Exhausted 11 March 22, ZOO, 3.4 mph. 28 min. Not tired 13 "Left innominate vein pressure (mm. Hg) measured in the upright position. vein 4 mm. cephalad to the autogenous vein graft. Flow in the fistula, determined electromagnetically, exceeded 475 ml. per minute. The immediate postoperative course was complicated by atelectasis and pneumonitis that responded to aggressive therapy. Innominate vein pressure measured in September, 197 1, and March, 1972, was unaltered by exhaustive exercise (Table 3). Examination on the former date indicated that a loud bruit was present over the entire precordium. On the latter date the bruit was audible in a 10 x 10 cm. area over the manubrium. At this time, cardiac output measured by the indocyanine green dye-dilution technique was normal. The dye-dilution curve showed no evidence of arteriovenous shunting. In September, 1972, the bruit was detectable at only one point over the manubrium during deep expiration. Venograms on these three dates showed a patent SVC that was essentially unchanged (Fig. 3B). The patient has resumed normal activities, including strenuous physical exercise. Comment: The SVC became occluded some time after the thoracotomy. Occlusion aggravated his symptoms to an intolerable point. Operation was postponed until our experimental study [7] was completed. When he was last seen the SVC was patent and there was no clinical sign of SVC obstruction. He was periorming hazardous duty as a paratrooper. Comment Superior vena caval obstruction secondary to fibrosing mediastinitis is seldom life-threatening. However, the quality of life is dependent upon the degree of obstruction and the adequacy of collateral circulation. Nonreconstructive management in this series does not compare favorably with the reconstructive management of SVC obstruction. At least 2 patients who did not undergo SVC reconstruction are severely symptomatic and limited in their activities. On the other hand, the 4 patients who had reconstruction are asymptomatic, and none is limited in activity. Only 1 of these, Patient 8, has a normally functioning SVC. Surgical reconstruction of the SVC has not been consistently successful, probably because thrombosis in the region of the suture lines has led to occlusion of the graft. However, in an experimental study [7] we have shown 490 THE ANNALS OF THORACIC SURGERY

9 Correction of Superior Vena Caval Obstruction in dogs that an arteriovenous fistula protects an autogenous vein graft. In this study the SVC was maximally replaced in 15 animals. The grafts functioned normally for one year. Early thrombus formation at the suture lines disappeared within two weeks of operation. We concluded that the efficacy of the shunt was related to turbulence in the graft preventing thrombus retention. During an operative procedure to reconstruct an occluded SVC, the ligneous mass should not be totally excised for fear of transecting the right phrenic nerve. This would increase the postoperative morbidity with probable pulmonary changes secondary to histoplasmosis. Second, injury to the right pulmonary vessels could well prolong the operative procedure. Third, attempts should be made to provide adequate space for the vein autograft to lie free of the aorta, the inflammatory mass, and the manubrium. An adequate length of autogenous vein may be harvested from the noncritical vessels, such as the cephalic vein or the saphenous vein used in Patient 8 and described elsewhere [2, 81. Increased venous pressure in the upper extremities as a result of fibrosing mediastinitis provides an adequate-sized cephalic vein, obviating a temporary radial artery-tocephalic vein fistula to increase its size prior to operation. A small tributary of the saphenous vein affords an adequate-sized specimen for use as a shunt. The internal thoracic artery may be of appropriate size. However, the difficult dissection of this vessel from a fibrotic mediastinum is time-consuming. Reconstruction of an obstructed SVC, as seen in Patient 4 (cf. Fig. Z), requires isolation of the SVC above and below the inflammatory mass. Suturing the venous autograft end-to-end with the complementary cephalad fistula then provides successful anatomical and functional results. Reconstruction for an obstruction involving the caudal portions of the left and right innominate veins, as seen in Patient 3 (cf. Fig. l), requires dissection of the free segments and interposition of a Y-shaped venous autograft complemented with two cephalad fistulas. When the graft is of excessive length, there should be concern for the possibility of stricture occurring at the caudal suture line. Thus, two fistulas, one at each suture line, may be required. Flow measurements are necessary postoperatively to insure that cardiac output is not increased beyond the compensatory ability of the patient. The arteriovenous fistula, we believe, will close spontaneously. If this has not occurred within two years or if the shunt becomes enlarged beyond the three- or four-week critical period, surgical closure is necessary. Anticoagulant therapy during the postoperative period is unnecessary in SVC reconstruction when a complementing fistula is used with an autogenous vein graft. However, to prevent bacterial vasculitis in the area of the fistula, prophylactic antibiotics should be used for patients having upper respiratory diseases, dental work, or other surgical procedures.

10 MILLER AND SULLIVAN Refer en ces 1. Barrett, N. R. Idiopathic mediastinal fibrosis. Br. J. Surg , Benvenuto, R., Rodman, F. S. B., Gilmour, J., Phillips, A. F., and Callaghan, J. C. Composite venous graft for replacement of the superior vena cava. Arch. Surg. 84:570, Boruchow, I. B., and Johnson, J. Obstructions of the vena cava. Surg. Gynecol. Obstet. 134: 115, Effler, D. B., and Groves, L. K. Superior vena caval obstruction. J. Thorac. Cardiouasc. Surg. 43:574, Hewlett, T. H., Steer, A., and Thomas, D. E. Progressive fibrosing mediastinitis. Ann.Thorac. Surg. 2:345, Miller, D. B., Allen, S. T., and Amidon, E. L. Obstruction of the superior vena cava presumably due to histoplasmosis. Am. Rev. Tuberc. 77:848, Miller, R. E., Corneil, N. J., and Sullivan, F. J. Replacement of superior vena cava with autogenous tissue: An experimental study. Ann. Thorac. Surg. P. 474, this issue. 8. Rheinlander, H. F. Superior vena cava replacement: Report of a successful autogenous composite vein graft. J. Thorac. Cardiovasc. Surg. 57:774, Salyer, J. M., Harrison, H. N., Winn, D. F., Jr., and Taylor, R. R. Chronic fibrous mediastinitis and superior vena caval obstruction due to histoplasmosis. Dis. Chest 35:364, Sisler, G. E., and Tice, D. A. RadicaI right pneumonectomy using preserved allograft vein for caval replacement. Ann. Thorac. Surg. 14:299, THE ANNALS OF THORACIC SURGERY