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Embolization of caval umbrella
Embolization of caval umbrella Discussion and report of successful removal from the right ventricle The first case of successful diagnosis and operative removal of a vena caval umbrella which had become detached and migrated to the right ventricle is reported. Complications from the employment of this device are discussed. In all cases of umbrella embolization to the right heart and pulmonary arterial tree, immediate operative removal is indicated. Precautions regarding umbrella insertion which minimize the likelihood of dislodgment and embolization are also mentioned. John H. Isch, M.D., and Harris B Shumacker, Jr., M.D., Indianapolis,
A he inferior vena caval umbrella filter, as designed by Dr. Mobin-Uddin, is widely recognized as a very useful device for vena caval interruption. 1 " 5 The morbidity and mortality rates associated with its placement are minimal when the umbrella is inserted correctly in properly selected patients. 6 Likewise, it has proved to be quite effective in preventing further episodes of pulmonary emboli. B Various complications have been reported from the use of this device. This report documents the recognition and operative management of an umbrella which became dislodged from the inferior vena cava and migrated to the right ventricle. The successful management of this complication has not been previously described. Case report The patient was a 27-year-old man admitted to another hospital following the acute onset of left-sided pleuritic chest pain and dyspnea. He had previously been in excellent general health. Although clinical and radiologic evidence was lacking, a provisional diagnosis of bronchopneumonia was made. He was treated with antibiotics for 2 weeks with little clinical response. A lung scan obtained 2 weeks after his admission (Fig. 1) revealed a massive perfusion defect. He was immediately given systemic heparin therapy and maintained on anticoagulant therapy for 3 days. At that time, a vena caval umbrella was inserted uneventfully. A roentgenogram of the abdomen obtained immediately From the Division of Thoracic and Cardiovascular Surgery, St. Vincent Hospital, and Indiana University Medical Center, Indianapolis, Ind. 46260. Received for publication April 23, 1976. Accepted for publication May 14, 1976. 256
Ind.
following the insertion revealed the umbrella to be at about the second lumbar interspace (Fig. 2). The patient did well for the initial 6 hours. He then had a sudden episode of severe, crushing pain in the anterior part of the chest and hypotension. With appropriate volume expansion therapy, his condition stabilized clinically. No arterial blood gas data were obtained. Dislodgment of the filter, however, was suspected and a chest x-ray film confirmed that the umbrella had migrated to the mediastinal area. Eighteen hours later, the patient was transferred to our institution for further treatment. On admission, he was symptom free and breathing comfortably in the supine position. He was very obese, weighing 280 pounds, and was 6 feet tall. The heart rate was 75 beats per minute and blood pressure 130/70 mm. Hg. The lung fields were clear bilaterally. Cardiac examination revealed a regular rhythm with a modest parasternal lifting impulse. There was an accentuated pulmonary second sound but no gallop, murmur, or bruit. Except for mild tenderness in the right upper quadrant, findings from the abdominal examination were quite normal. He had no peripheral evidence of acute or chronic thrombophlebitis. Findings from immediate laboratory studies, including a complete blood count, electrolytes, chem. 12, and amalyase, were not remarkable. While he was breathing room air. the arterial Po2 was 75 mm. Hg with an oxygen saturation of 98 per cent and a Pco2 of 37 mm. Hg. The chest x-ray film demonstrated hyperlucent lung fields and dilated pulmonary arteries, with the umbrella filter lying within the cardiac silhouette. The electrocardiogram showed sinus rhythm with right axis deviation. The patient was taken directly to the cardiac catheterization laboratory where an inferior vena cavogram was obtained by way of the femoral vein. A large submural caval thrombus was noted. A forward pulmonary angiogram revealed a massive amount of embolic material in the left and right main pulmonary arteries and their branch vessels. The patient was taken directly to the operating room where, through a right flank approach, the inferior vena cava
Volume 72 Number 2 August, 1976
was mobilized but not ligated. The heart was exposed through a sternotomy incision. The right atrium, the right ventricle, and the pulmonary artery were quite tense and the right ventricular pressure measured 50/10 mm. Hg. After appropriate cannulations, cardiopulmonary bypass was begun and the right atrium opened. The umbrella was immediately seen to be entangled in the chordal mechanism of the tricuspid valve within the right ventricle. There was no gross clot in the right atrium or ventricle. The umbrella was removed uneventfully and the atriotomy closed. The pulmonary artery was opened and a pulmonary emboleetomy performed. A large amount of old thrombus was removed from both the main and branch pulmonary arteries. The patient's own cardiac function was restored, after which the right ventricular pressure was found to have dropped to 25/5 mm. Hg. The inferior vena cava was ligated just below the renal veins, and both the sternotomy and flank incisions were repaired. Postoperatively, the patient did quite well. He developed mild phlebitis in the right side of the groin and in the right thigh for which he was treated with heparin anticoagulation, bed rest, elevation of the limb, and pressure support elastic bandages. Otherwise, he recovered quite uneventfully. The patient has been seen intermittently for 2 years since his operative treatment. He continues to be active and generally well. He wears elastic support hose continuously and has only minimal residual evidence of chronic edema of the lower extremity. Comment. The simplicity of insertion and effectiveness in preventing recurrent pulmonary emboli are very desirable features of the Uddin inferior vena caval umbrella. Among the complications which have been reported are vena caval perforation with retroperitoneal hematoma, 7 duodenal and ureteral perforation, 7 air embolism, 6 proximal thrombus propagation with renal vein obstruction and renal failure, 6 filter misplacement into the renal and iliac veins and the suprarenal inferior vena cava, 5 mild-to-moderate edema of the lower extremity, 5 and generalized sepsis. 6 Filter dislodgment and migration is certainly among the most serious and potentially dangerous of these complications. It is estimated that there have now been over 10,000 vena caval umbrellas inserted. 8 Twenty-two cases of filter dislodgment and proximal migration (0.23 per cent incidence) are known to have occurred. Umbrellas have become lodged in the suprarenal inferior vena cava, right atrium, right ventricle, and pulmonary arterial tree. Not included in this number are six umbrellas which migrated into the right iliac vein during external cardiac massage. 8 The recognition and successful removal of an umbrella from the right ventricle has not been previously described. This case illustrates once more that the technique of insertion is critically important for longterm stability of the device. In our patient, the filter was placed too high in the inferior vena cava. Consequently, rather than having engaged the vena cava
Embolization
of caval umbrella
257
Fig. 1. Preoperative lung scan. securely circumferentially just below the renal veins, it probably engaged one of the renal venous orifices. This predisposed it to instability and migration. Accurate localization of the renal veins is imperative to allow proper positioning of the umbrella. Fluoroscopically identified bony landmarks and pyelographically identified renal shadows do not provide adequate anatomic localization for placement of the umbrella. Venograms of the lower extremities are also of little benefit because they do not accurately define caval anatomy. Inferior vena cavograms are helpful in estimating caval size, contained thrombus, and unsuspected anatomic abnormalities but do not always accurately identify the renal veins. The renal veins can be simply and accurately localized at the time of umbrella insertion. Prior to filter placement, a small catheter can be inserted into the inferior vena cava through the exposed internal jugular vein. Then, by hand injecting the contrast dye and observing the negative density streaming of the renal venous blood with a fluoroscope, one can locate the renal venous orifices. Should this technique be unsatisfactory, selective cannulation of renal veins can be readily performed. Placement of the umbrella at least 1 inch below the renal venous orifices ensures adequate seating of the umbrella with secure engagement of the wire prongs into the caval wall. Thus the potential problem of instability and dislodgment is minimized. Selection of the proper-sized umbrella also ensures more secure seating. The newly designed 28 mm. diameter filter with 2 mm. extended prongs should be used in all patients weighing more than 60 kilograms and in all patients whose inferior vena cava is larger than 2 cm. in its transverse diameter as measured by
258
Isch and
Shumacker
The Journal of Thoracic and Cardiovascular Surgery
Fig. 2. X-ray film of abdomen demonstrating vena caval umbrella at the level of the second lumbar vertebra. contrast study. Twenty of the 22 reported cases of umbrella migration have involved the initially designed 23 mm. umbrella. 6 The recent availability of the larger size should lessen the risk of migration. Certainly, whenever umbrella embolization is suspected, urgent diagnostic and therapeutic measures are indicated. There are 3 known cases of umbrella migration to the suprarenal vena cava. 6 None of these patients was operated upon. Two later died of unrelated causes. The third patient is alive and well with a patent vena cava. However, there remains concern that further migration might occur. Nevertheless, because of the difficulty of removing the umbrella from the inferior vena cava in the area of the hepatic veins, continued serial follow-up would seem advisable in these cases rather than attempted operative retrieval. In all cases of umbrella migration to the right side of the heart or pulmonary arterial tree, on the other hand, immediate operative removal is indicated. The umbrella can be easily and safely extracted from the right atrium and ventricle, and thereby the risk of embolization into the pulmonary arterial tree is eliminated. Once the umbrella has moved beyond the pulmonary valve, the threat of massive arterial thrombosis and subsequent sudden death is great. Of 13 patients in whom the umbrellas was known to have passed into the pulmonary arterial tree, 3 have died as a result of massive thrombosis. 6 In addition, there remians the long-term problem of sepsis from the indwelling umbrella.
This unusual complication of vena caval umbrella insertion is not presented to discredit the umbrella. Rather, it is described with the intention of reemphasizing the importance of exacting surgical placement techniques. If these are followed carefully, we believed that these potentially lethal complications can be nearly eliminated. REFERENCES 1 Mobin-Uddin, K., Bolooki. H., and Jude, J. R.: Intravenous Caval Interruption for Pulmonary Embolism in Cardiac Disease, Circulation 41: 153, I970(Suppl. II). 2 Mobin-Uddin, K., Callard, G. M., Bolooki, H.. et al.: Transvenous Caval Interruption With Umbrella Filter. N. Engl. J. Med. 286: 55, 1972. 3 Mobin-Uddin, K., McLean. R., Bolooki, H., et al.: Caval Interruption for Prevention of Pulmonary Embolism; Long-Term Results of a New Method, Arch. Surg. 99: 711, 1969. 4 Mobin-Uddin, K., Smith, P. E., Martines, L. D., et al.: A Vena Caval Filter for the Prevention of Pulmonary Embolus, Surg. Forum 18: 289. 1967. 5 Mobin-Uddin, K., Trinkle, J. K., and Bryant. L. R.: Present Status of the Inferior Vena Cava Umbrella Filter, Surgery 79: 914, 1971. 6 Mobin-Uddin, K., Utley, J. R., and Bryant. L. R.: The Inferior Vena Cava Umbrella Filter, Progr. Cardiovasc. Dis. 17: 391, 1975. 7 Mobin-Uddin, K., Trinkle, J. K., and Bryant, L. R.: Further Evaluation of Inferior Vena Cava Umbrella Filter, Bull. Soc. Int. Chir. 2: 149. 8 Mobin-Uddin, K.: Personal communication.
A he inferior vena caval umbrella filter, as designed by Dr. Mobin-Uddin, is widely recognized as a very useful device for vena caval interruption. 1 " 5 The morbidity and mortality rates associated with its placement are minimal when the umbrella is inserted correctly in properly selected patients. 6 Likewise, it has proved to be quite effective in preventing further episodes of pulmonary emboli. B Various complications have been reported from the use of this device. This report documents the recognition and operative management of an umbrella which became dislodged from the inferior vena cava and migrated to the right ventricle. The successful management of this complication has not been previously described. Case report The patient was a 27-year-old man admitted to another hospital following the acute onset of left-sided pleuritic chest pain and dyspnea. He had previously been in excellent general health. Although clinical and radiologic evidence was lacking, a provisional diagnosis of bronchopneumonia was made. He was treated with antibiotics for 2 weeks with little clinical response. A lung scan obtained 2 weeks after his admission (Fig. 1) revealed a massive perfusion defect. He was immediately given systemic heparin therapy and maintained on anticoagulant therapy for 3 days. At that time, a vena caval umbrella was inserted uneventfully. A roentgenogram of the abdomen obtained immediately From the Division of Thoracic and Cardiovascular Surgery, St. Vincent Hospital, and Indiana University Medical Center, Indianapolis, Ind. 46260. Received for publication April 23, 1976. Accepted for publication May 14, 1976. 256
Ind.
following the insertion revealed the umbrella to be at about the second lumbar interspace (Fig. 2). The patient did well for the initial 6 hours. He then had a sudden episode of severe, crushing pain in the anterior part of the chest and hypotension. With appropriate volume expansion therapy, his condition stabilized clinically. No arterial blood gas data were obtained. Dislodgment of the filter, however, was suspected and a chest x-ray film confirmed that the umbrella had migrated to the mediastinal area. Eighteen hours later, the patient was transferred to our institution for further treatment. On admission, he was symptom free and breathing comfortably in the supine position. He was very obese, weighing 280 pounds, and was 6 feet tall. The heart rate was 75 beats per minute and blood pressure 130/70 mm. Hg. The lung fields were clear bilaterally. Cardiac examination revealed a regular rhythm with a modest parasternal lifting impulse. There was an accentuated pulmonary second sound but no gallop, murmur, or bruit. Except for mild tenderness in the right upper quadrant, findings from the abdominal examination were quite normal. He had no peripheral evidence of acute or chronic thrombophlebitis. Findings from immediate laboratory studies, including a complete blood count, electrolytes, chem. 12, and amalyase, were not remarkable. While he was breathing room air. the arterial Po2 was 75 mm. Hg with an oxygen saturation of 98 per cent and a Pco2 of 37 mm. Hg. The chest x-ray film demonstrated hyperlucent lung fields and dilated pulmonary arteries, with the umbrella filter lying within the cardiac silhouette. The electrocardiogram showed sinus rhythm with right axis deviation. The patient was taken directly to the cardiac catheterization laboratory where an inferior vena cavogram was obtained by way of the femoral vein. A large submural caval thrombus was noted. A forward pulmonary angiogram revealed a massive amount of embolic material in the left and right main pulmonary arteries and their branch vessels. The patient was taken directly to the operating room where, through a right flank approach, the inferior vena cava
Volume 72 Number 2 August, 1976
was mobilized but not ligated. The heart was exposed through a sternotomy incision. The right atrium, the right ventricle, and the pulmonary artery were quite tense and the right ventricular pressure measured 50/10 mm. Hg. After appropriate cannulations, cardiopulmonary bypass was begun and the right atrium opened. The umbrella was immediately seen to be entangled in the chordal mechanism of the tricuspid valve within the right ventricle. There was no gross clot in the right atrium or ventricle. The umbrella was removed uneventfully and the atriotomy closed. The pulmonary artery was opened and a pulmonary emboleetomy performed. A large amount of old thrombus was removed from both the main and branch pulmonary arteries. The patient's own cardiac function was restored, after which the right ventricular pressure was found to have dropped to 25/5 mm. Hg. The inferior vena cava was ligated just below the renal veins, and both the sternotomy and flank incisions were repaired. Postoperatively, the patient did quite well. He developed mild phlebitis in the right side of the groin and in the right thigh for which he was treated with heparin anticoagulation, bed rest, elevation of the limb, and pressure support elastic bandages. Otherwise, he recovered quite uneventfully. The patient has been seen intermittently for 2 years since his operative treatment. He continues to be active and generally well. He wears elastic support hose continuously and has only minimal residual evidence of chronic edema of the lower extremity. Comment. The simplicity of insertion and effectiveness in preventing recurrent pulmonary emboli are very desirable features of the Uddin inferior vena caval umbrella. Among the complications which have been reported are vena caval perforation with retroperitoneal hematoma, 7 duodenal and ureteral perforation, 7 air embolism, 6 proximal thrombus propagation with renal vein obstruction and renal failure, 6 filter misplacement into the renal and iliac veins and the suprarenal inferior vena cava, 5 mild-to-moderate edema of the lower extremity, 5 and generalized sepsis. 6 Filter dislodgment and migration is certainly among the most serious and potentially dangerous of these complications. It is estimated that there have now been over 10,000 vena caval umbrellas inserted. 8 Twenty-two cases of filter dislodgment and proximal migration (0.23 per cent incidence) are known to have occurred. Umbrellas have become lodged in the suprarenal inferior vena cava, right atrium, right ventricle, and pulmonary arterial tree. Not included in this number are six umbrellas which migrated into the right iliac vein during external cardiac massage. 8 The recognition and successful removal of an umbrella from the right ventricle has not been previously described. This case illustrates once more that the technique of insertion is critically important for longterm stability of the device. In our patient, the filter was placed too high in the inferior vena cava. Consequently, rather than having engaged the vena cava
Embolization
of caval umbrella
257
Fig. 1. Preoperative lung scan. securely circumferentially just below the renal veins, it probably engaged one of the renal venous orifices. This predisposed it to instability and migration. Accurate localization of the renal veins is imperative to allow proper positioning of the umbrella. Fluoroscopically identified bony landmarks and pyelographically identified renal shadows do not provide adequate anatomic localization for placement of the umbrella. Venograms of the lower extremities are also of little benefit because they do not accurately define caval anatomy. Inferior vena cavograms are helpful in estimating caval size, contained thrombus, and unsuspected anatomic abnormalities but do not always accurately identify the renal veins. The renal veins can be simply and accurately localized at the time of umbrella insertion. Prior to filter placement, a small catheter can be inserted into the inferior vena cava through the exposed internal jugular vein. Then, by hand injecting the contrast dye and observing the negative density streaming of the renal venous blood with a fluoroscope, one can locate the renal venous orifices. Should this technique be unsatisfactory, selective cannulation of renal veins can be readily performed. Placement of the umbrella at least 1 inch below the renal venous orifices ensures adequate seating of the umbrella with secure engagement of the wire prongs into the caval wall. Thus the potential problem of instability and dislodgment is minimized. Selection of the proper-sized umbrella also ensures more secure seating. The newly designed 28 mm. diameter filter with 2 mm. extended prongs should be used in all patients weighing more than 60 kilograms and in all patients whose inferior vena cava is larger than 2 cm. in its transverse diameter as measured by
258
Isch and
Shumacker
The Journal of Thoracic and Cardiovascular Surgery
Fig. 2. X-ray film of abdomen demonstrating vena caval umbrella at the level of the second lumbar vertebra. contrast study. Twenty of the 22 reported cases of umbrella migration have involved the initially designed 23 mm. umbrella. 6 The recent availability of the larger size should lessen the risk of migration. Certainly, whenever umbrella embolization is suspected, urgent diagnostic and therapeutic measures are indicated. There are 3 known cases of umbrella migration to the suprarenal vena cava. 6 None of these patients was operated upon. Two later died of unrelated causes. The third patient is alive and well with a patent vena cava. However, there remains concern that further migration might occur. Nevertheless, because of the difficulty of removing the umbrella from the inferior vena cava in the area of the hepatic veins, continued serial follow-up would seem advisable in these cases rather than attempted operative retrieval. In all cases of umbrella migration to the right side of the heart or pulmonary arterial tree, on the other hand, immediate operative removal is indicated. The umbrella can be easily and safely extracted from the right atrium and ventricle, and thereby the risk of embolization into the pulmonary arterial tree is eliminated. Once the umbrella has moved beyond the pulmonary valve, the threat of massive arterial thrombosis and subsequent sudden death is great. Of 13 patients in whom the umbrellas was known to have passed into the pulmonary arterial tree, 3 have died as a result of massive thrombosis. 6 In addition, there remians the long-term problem of sepsis from the indwelling umbrella.
This unusual complication of vena caval umbrella insertion is not presented to discredit the umbrella. Rather, it is described with the intention of reemphasizing the importance of exacting surgical placement techniques. If these are followed carefully, we believed that these potentially lethal complications can be nearly eliminated. REFERENCES 1 Mobin-Uddin, K., Bolooki. H., and Jude, J. R.: Intravenous Caval Interruption for Pulmonary Embolism in Cardiac Disease, Circulation 41: 153, I970(Suppl. II). 2 Mobin-Uddin, K., Callard, G. M., Bolooki, H.. et al.: Transvenous Caval Interruption With Umbrella Filter. N. Engl. J. Med. 286: 55, 1972. 3 Mobin-Uddin, K., McLean. R., Bolooki, H., et al.: Caval Interruption for Prevention of Pulmonary Embolism; Long-Term Results of a New Method, Arch. Surg. 99: 711, 1969. 4 Mobin-Uddin, K., Smith, P. E., Martines, L. D., et al.: A Vena Caval Filter for the Prevention of Pulmonary Embolus, Surg. Forum 18: 289. 1967. 5 Mobin-Uddin, K., Trinkle, J. K., and Bryant. L. R.: Present Status of the Inferior Vena Cava Umbrella Filter, Surgery 79: 914, 1971. 6 Mobin-Uddin, K., Utley, J. R., and Bryant. L. R.: The Inferior Vena Cava Umbrella Filter, Progr. Cardiovasc. Dis. 17: 391, 1975. 7 Mobin-Uddin, K., Trinkle, J. K., and Bryant, L. R.: Further Evaluation of Inferior Vena Cava Umbrella Filter, Bull. Soc. Int. Chir. 2: 149. 8 Mobin-Uddin, K.: Personal communication.