Recurrent Pulmonary Emboli after Inferior Vena Caval Clipping SUBHAS
C. MULLICK,
MB, BS, FRCS (Eng), Boston,
H. BROWNELL WHEELER, MD, FACS, Boston,
Narrowing of the inferior vena cava by a plastic clip has been reported to prevent recurrent pulmonary emboli and to avoid the acute and chronic complications of complete interruption of the inferior vena cava [I-6]. Despite this generally favorable experience, clipping of the inferior vena cava has been followed by one fatal pulmonary embolus and another near-fatal embolus in this hospital. These two case reports and a discussion of the possible mechanisms producing the emboli form the basis of the current article. Case
Reports
CASE I. The patient (BM, # 01 l-16-5722)) a forty-six year old white male school teacher, was admitted to the hospital because of sudden shortness of breath, sweating, and dizziness. Three days previously, the patient had been discharged from the hospital after a one month period of hospitalization because of acute myocardial infarction. During the first three weeks of his hospitalization he was markedly restricted in activity. Physical examination revealed the patient to be in mild respiratory distress with respiration of 30 per minute, pulse of 110 per minute, and blood pressure of 130/80 mm Hg. There was no leg swelling, calf tenderness, or Homans’ sign. The electrocardiogram showed no change from previous tracings. Pulmonary angiograms showed decreased vascularity in the entire right lung field, with delayed emptying of the arterial phase. The pulmonary artery pressure was 30/15 mm Hg. A diagnosis of acute pulmonary embolism was made, and the patient was treated with intravenous heparin. Consecutive lung scans showed evidence of new anticoagulation. adequate pulmonary emboli despite Twelve days after admission, a Moretz clip with a 3.5 mm aperture was placed across the inferior vena cava just below a large lumbar vein. The procedure was technically uneventful. Pressure readings on either side of the clip disclosed no pressure gradient. The patient did not receive anticoagulants postoperatively. He did well until the seventh day, when he abruptly died. Autopsy showed massive pulmonary embolization with complete occlusion of the main pulmonary artery. There was an old anteroseptal myocardial infarction, but no apparent source of mural thrombosis within the right side of the heart. The clip was found intact and there From the Surgical Service, Veterans Administration Hospital, West Roxbury, Medical
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Massachusetts, School, Boston,
and the Department Massachusetts.
of
Surgery.
Harvard
Massachusetts
Massachusetts
was no clot distal to the clip. A large thrombus was found extending from a lumbar vein adjacent to the clip into the proximal inferior vena cava. There was considerable inflammatory reaction around the clip.
Comment: From the clinical course and the autopsy findings, it is clear that the patient died abruptly from a massive pulmonary embolus occurring seven days after a partially occlusive clip was placed around the inferior vena cava. No source for the embolus was found in the heart. The embolus could not have arisen distal to the clip, since the aperture was only 3.5 mm. There was considerable inflammatory reaction around the clip involving an adjacent lumbar vein. This vein had thrombosed and the clot had propagated into the inferior vena cava above the clip. (Figure 1. ) CASE II. The patient (MJK, # 014-14-6106), a fortyseven year old unemployed white man, was admitted to the hospital because of confusion, memory disturbance, and disorientation. He had previously been diagnosed as suffering from “chronic brain syndrome,” alcoholism, and malnutrition. Past history included thrombophlebitis with multiple pulmonary emboli for which the patient had been maintained on Coumadin@. Physical examination revealed an obese middle-aged man who responded slowly to questions and who had a swollen tender left leg with a positive Homans’ sign. In view of the patient’s unreliability, it was believed that inferior vena cava clipping should be substituted for long-term oral anticoagulation. A Moretz clip measuring 3.5 mm was applied to the inferior vena cava. On the sixth post-operative day pleuritic chest pain, hemoptysis, and low grade fever developed. Pulmonary angiogram revealed a new occlusion of the artery to the right upper lobe. The patient was heparinized and did well initially, After a week he was placed on warfarin. Heparin was discontinued when the patient’s prothrombin time reached 20 per cent of normal. Five days later, severe pleuritic chest pain, fever, and a left pleural effusion developed. At this time, the prothrombin time was 39 per cent of normal. Repeat pulmonary angiograms revealed new filling defects in several arteries supplying the left lower lobes. The patient became hypotensive during angiography and was moved to the operating room for emergency pulmonary embolectomy. His condition stabilized, however, and an inferior vena caval ligation was carried out instead of pulmonary embolectomy. A trans-
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Figure 1. Case 1. A, autopsy photograph of the inferior vena cava. The plastic clip has been removed, the cava has been opened, and the clip has been laid across the site of its original location. Fresh clot propagating out of a thrombosed lumbar vein can be seen on the posterior wall of the cava. 6, photomicrograph showing the close relationship of the thrombosed lumbar vein to the clip. The location of the soft clot found in the inferior vena cava is indicated by stippling.
peritoneal approach was employed, and the inferior vena cava was ligated just below the renal veins. The clip was found in place as expected, but an intraoperative angiogram of the inferior vena cava disclosed a thrombus above the clip. The patient had an uneventful postoperative course, except for some edema of the left leg. The diagnosis of recurrent pulmonary embolism after clipping was confirmed by pulmonary angiograms and lung scans, as well as the intraoperative angiogram which showed clot above the inferior vena caval clip. It is not possible to prove the mechanism whereby clot formed above the clip. In view of the known thrombophlebitis in the legs and the previous pulmonary emboli, a logical possibility would be that a new embolus from the legs lodged below the clip with clot propagating through the clip into the proximal inferior vena cava. Comment:
Comments In 1944, Homans [7] first suggested that life-endangering pulmonary emboli from the lower half of the body might be prevented by ligation of the inferior vena cava. Since this time innumerable patients have undergone inferior vena caval interruption. The literature contains a number of references attesting to the infrequent occurrence of recurrent pulmonary emboli after this procedure [8-101. Many references also cite a significant morbidity due to venous stasis in the lower limbs [SJO-131. Furthermore, the intraoperative trapping of blood below the tie may cause acute hypovolemia [14]. For these reasons a number of procedures have been devised to narrow or segment the vena cava without its complete occlusion [2-4,15]. Currently, the most popular of these procedures involve placement of partially occlusive plastic clips.
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The incidcncc (lf recurrent pulnlonary emboli has been reported to hc low after the use of inferior vena caval clips [2-4,6,/51; but the occurrence of one fatal and one near-fatal recurrent pulmonary embolus in the first year in which such a technic was employed in our own hospital has made us question the reliability of this method for preventing major recurrent emboli. It is easy to visualize how an embolus trapped by the clip can propagate through its limbs into the unprotected proximal inferior vena cava. In this location the thrombus can become dislodged and form a new pulmonary embolus. We presume that this is the mechanism of recurrent embolization in the second case reported. Propagation of thrombus above a clip has been described previously by Brickman, Fisher. and Haller
[161. Another way in which clot can form above a clip is demonstrated by the first case reported. In this patient an inflammatory reaction occurred around the clip and an adjacent lumbar vein. This vein became the site of a thrombosis which then propagated into the inferior vena cava and presumably formed the site of origin of the fatal embolus. Neither patient was receiving adequate postoperative anticoagulant therapy at the time of recurrent embolization. The literature has little to say about postoperative anticoagulant therapy in patients undergoing partial interruption of the inferior vena cava. Some authors apparently use anticoagulant therapy routinely [6,15], but others recommend anticoagulants only in patients with clinical evidence of thrombophlebitis [3]. Most papers make no comment concerning the value of postoperative anticoagulants. Skinner and Salzman [I 71 have recently advocated routine postoperative anticoagulation for all “high risk” surgical patients,
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including those with a past history of thrombophlebitis or pulmonary emboli. Based on their data and our own limited experience, we strongly recommend routine postoperative use of anticoagulants in all patients undergoing partial interruption of the inferior vena cava. Summary Two patients are reported in whom massive pulmonary embolization recurred after the inferior vena cava was narrowed by a plastic clip. Clot which had formed above the clip was the source of the emboli. In the absence of effective anticoagulant therapy, clipping of the inferior vcna cava is not an infallible method for preventing recurrent pulmonary emboli. We would like to express our Acknowledgment: indebtedness to Dr Edward 0. Fox for his assistance in the interpretation of the pathology in the first case and to Dr Arthur A. Sasahara for his assistance in the clinical evaluation of both patients during their hospitalization. References 1. Adams JT, DeWeese JA: Experimental and clinical evaluation of partial vein interruption in prevention of pulmonary emboli. Surgery 57: 82, 1965. 2. DeWeese JA, Hunter DC Jr: A vena cava filter for prevention of pulmonary embolism: five-year clinical experience. Arch Surg 86: 852, 1963. 3. Miles RM, Chappell F, Renner 0: A partially occluding vena caval clip for prevention of pulmonary embolism. Amer Surg 30: 30, 1964.
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4. Tabor RE, Zikria E, Hershey EA, Lam CR: Prevention of pulmonary embolism with vena cava clip. JAMA 195: 889, 1966. 5. Wheeler CG, Thompson JE, Austin DJ, Patman RD, Stockton RL: Interruption of inferior vena cava for thromboembolism: comparison of ligation and plication. Ann Surg 163: 199; 1966. 6. Moretz WH. Rhode CM. Sheohard MH: Prevention of pulmonary emboli by pa&al occlusion of inferior vena cava. Amer Surg 25: 617, 1959. 7. Homans J: Disease of veins. New Eng J Med 231: 51, 1944. 8. Crane C: Femoral vs. caval interruption for venous thromboembolism. New Eng J Med 270: 819, 1964. 9. Mozes M, Adar R, Bogokowsky H, Agmon M: Vein ligation in treatment of pulmonary embolism. Surgery 55: 621, 1964. 10. Nabseth DC, Moran JM: Reassessment of the role of inferior vena cava ligation in venous thromboembolism. New Eng J Med 273: 1250, 1965. 11. Agrifoglio G, Edward EA: Venous stasis after ligation of femoral veins or inferior vena cava. JAMA 178: 1, 1961. 12. Bowers RF, Leb SM: Late results of inferior vena cava ligation. Surgery 37: 622, 1955. 13. Shea PC Jr, Robertson RL: Late sequela of inferior vena cava ligation. Surg Gynec Obstet 93: 153, 1951. 14. Gazzaniga AB, Cahill JL, Replogl,e RL, Tilney NL: Changes in blood volume and renal function following ligation of the inferior vena cava. Surgery 62: 417, 1967. 15. Spencer FC, Quattlebaum JK, Quattlebaum JK Jr, Sharp EH, Jude JR: Plication of inferior vena cava for pulmonary embolism: report of 20 cases. Ann Surg 155: 827, 1962. 16. Brickman RD, Fisher RD, Haller JA: Vena cava thrombosis after plication for pulmonary emboli. JAMA 196: 911,1966. 17. Skinner DB, Salzman EW: Anticoagulant prophylaxis in surgical patients. Surg Gynec Obstet 125: 741, 1967.
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