Small-bowel obstruction from an extruded Greenfield filter strut: An unusual late complication J o h n P. K u p f e r s c h m i d , ME), C h r i s t o p h e r S. Dickson, M D , R i c a r d N. T o w n s e n d , M D , and Daniel L. D i a m o n d , M D , Pittsburgh, Pa.
Recently interest has been shown in liberalizing the indications for insertion ofvena caval filters. The convenience of percutaneons insertion by radiologists may further perpetuate this trend. However, filter placement is not without morbidity. We report a unique late complication in which a small-bowel obstruction occurred as a result of volvulus around an extruded filter strut. (J VASC SURG 1992;16:113-5.) Deep venous thrombosis (DVT) is a c o m m o n medical problem that affects several million people annually and progresses to pulmonary embolization in an estimated 600,000 cases annually. 1'2 Approximately one third o f pulmonary emboli are fatal. 2 Standard treatment o f both D V T and pulmonary embolism includes the following: bed rest, anticoagulation, and, in some instances, vena caval interruption. The Greenfield filter is currently the most popular method o f caval interruption. Greenfield filters have been in use since 1973. This filter is effective in maintaining a caval patency rate o f 96%, with low procedure morbidity and mortality rates, s T o date, complications related to this filter have been u n c o m m o n and usually are the result o f technical errors at the time o f insertion. Reported complications include embolizatlon caused by the filter,4 proximal migration, 4,5 distal migration, 5 bowel perforation, 6,z structural failure o f the filter, s femoral arteriovenous fistula, 9 and perforation o f the vena cava by the filter struts. 6's'l°'n We report here a case o f penetration o f the vena cava by a filter strut, resulting in a small-bowel obstruction caused by volvulus around this strut.
CASE R E P O R T A 19-year-old white woman was admitted to our trauma center on Sept. 27, 1987, after being struck by a car while walking. She suffered a right hemopneumothorax, a basilar skull fracture with subarachnoid hemorrhage, pelvic From the Department of Surgery, Division of General Surgery, Allegheny General Hospital, Pittsburgh. Reprint requests: Daniel L. Diamond, MD, Director Division of General Surgery, Allegheny General Hospital, 320 E. North Ave., Pittsburgh, PA 15212-9986. 24/4/35062
fractures that required external fixation, a closed right tibial fracture, and a dosed left fibular fracture. Early in her hospital course she had pulmonary emboli documented by pulmonary angiography. Because of the head injury and multiple fractures heparin was contraindicated, and a Greenfield filter was placed via an internal jugular cutdown on Oct. 2, 1987, with the patient under local anesthesia. The postoperative roentgenogram showed the falter at the inferior aspect of the third lumbar vertebral body (Fig. 1). During an orthopedic operation performed 10 days later, with the patient under general anesthesia, the patient had a hypertensive crisis. Urine metanephrine was elevated, and CT scanning showed a periaortic mass. On Nov. 3, 1987, she underwent abdominal exploration and resection of a paraganghoma. The paraganglioma was located on the anterior surface of the aorta at approximately the level of the first lumbar vertebral body. The tumor was located superior to the level of the filter. No effort was made to palpate the filter or locate it during the operation. Postoperative abdominal roentgenography showed no distortion of the filter struts. On Apr. 6, 1989, the patient was admitted with diffuse, severe, crampy abdominal pain. Abdominal roentgenograms supported the clinical diagnosis of small-bowel obstruction and showed distortion of one of the filter struts. At operation, a loop of smaU bowel was "hooked" to the floor of the abdomen by a metal strut from the Greenfield filter. The strut protruded from the anterior wall of the vena cava and through the mesentery. The small bowel had twisted around this point leading to vohaalus. The wire was clipped flush with the cava, and the volvulus was reduced. She was returned to the operating room the following morning for a "second-look" procedure. No bowel was resected. She was discharged on the sixth postoperative day. Six weeks later, the patient was admitted with severe back pain associated with nausea and vomiting. An abdominal roentgenogram showed an ileus as well as fracture of one of the filter struts (Fig. 2). A CT scan of the 113
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Fig. 1. Postoperative roentgenogram after Greenfield filter was inserted via right internal jugular cutdown. Paper clip placed on patient's back before operation for appropriate placement of filter.
abdomen confirmed fracture of one of the filter struts and showed downward migration of the filter hub and the remaining attached five struts, as compared with a previous CT scan of the abdomen. In addition, several struts were thought to be protruding through the wall of the vena cava (Fig. 3). There was no evidence of any paricaval hematoma or mass. At operation, a 10 cm length of the vena cava, which included the filter, was sharply freed from the surrounding tissues. All five of the remaining full-length struts were outside the caval wall for lengths of 1 to 2 cm, including the one that had fractured at the hub. The vena cava was opened, and each of the struts was clipped and withdrawn through the wall of the cava. One of the posterior struts had penetrated into an intervertebral disk space, presumably explaining the presenting back pain. The findings inside of the cava included fracture of one of the struts at the strut-hub juncture. A curtainlike coverage of the struts of the filter against the walls of the vein was noted. The filter was removed, and the cava was closed.
DISCUSSION Vena caval filters have a definite role in the m a n a g e m e n t o f p u l m o n a r y embolus. T h e increased
Journal of VASCULAR SURGERY
Fig. 2. Roentgenogram taken when patient was admitted with back pain. Filter now located at superior aspect of fourth lumbar vertebral body. Note that one filter strut has separated from hub.
case findings o f D V T as a result o f noninvasive venous studies have resulted in insertion o f larger n u m b e r s o f caval filters. T o date, the safety profile o f the Greenfield filter has been admirable. It has been associated with a long-term caval patency o f 9 6 % and has been s h o w n to reduce dramatically the incidence o f fatal p u l m o n a r y e m b o l i s m f r o m sources below the heart. 3 H o w e v e r , filter placement is n o t w i t h o u t complications. We report here a small-bowel obstruction that occurred as a result o f volvulus a r o u n d an extruded filter strut. W h y one o f the struts had penetrated the anterior surface o f the vena cava is not clear. T h e patient had u n d e r g o n e resection o f a periaortic paraganglioma after placement o f the Greenfield filter. A l t h o u g h the t u m o r was located above the filter, it is possible that pressure was placed on the filter during this procedure. An abdominal r o e n t g e n o g r a m obtained after resection o f the manor showed no significant deformity o f the filter. H o w -
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Fig. 3. C o m p u t e d tomographic scan o f the abdomen shows struts protruding through wall of vena cava.
ever, an anteroposterior view may have missed deformity of a strut if it was protruding anteriorly. This patient's small-bowel obstruction was treated by clipping the extruded strut flush with the vena cava and reducing the volvulus. An abdominal roentgenogram obtained after this procedure showed no further deformity of the filter. A C T scan of the abdomen obtained when the patient returned 6 weeks later showed downward migration of the filter and extrusion of the remaining five struts. It is possible that the migration of the filter was related to the fact that one of the struts had been clipped during the operation for the bowel obstruction. SUMMARY Several Conclusions can be drawn on the basis of our experience. First, surgeons must be careful when performing intraabdominal operations on patients with vena cava filters because pressure on the vena cava from retractors may distort the filter. Second, clipping one strut of the filter may make the filter more likely to migrate; therefore, filters should be removed entirely if they cause a significant complication. And finally, extrusion of a filter strut through the anterior wall of the vena cava can result in bowel injury and obstruction. REFERENCES
1. Coon W. Epidemiology of venous thromboembolism. Ann Surg 1977;186:149-64.
2. Dalen JE, Alpert JS. Natural history of puhnonary embolism. Prog Cardiovasc Dis 1975;17:257-70. 3. Greenfield LJ, Michna BA. Twelve-year clinical experience with the Greenfield vena caval filter. Surgery 1988;104:70612. 4. Castaneda F, Herrera M, Cragg AH, et al. Migration of a Kimray-Greenfield filter to the right ventricle. Radiology 1983; 149:690. 5. FriedeU M, Goldenkranz R, Parsonett V, et al. Migration of a Greenfield filter into the pulmonary artery: a case report. J VASC SURG 1986;3:929-31. 6. Sidawy AN, Menzoian JO. Distal migration and deformation of the Greenfield vena cava filter. Surgery 1986;99:36972. 7. Balshi JD, Cantelmo NL, Menzoin JD. Complications ofcaval interruption by Greenfield filter in quadriplegics. J VAsc SuRe 1989;9:558-62. 8. Plaus WJ, Hermann G. Structural failure of a Greenfield filter. Surgery 1988;103:662-4. 9. Grassi CJ, Bettmann MA, Rogoff P, Reagan K, Harrington DP. Femoral arteriovenous fistula after placement of a Kimray-Greenfield filter. AJR 1988;151:681-2. 10. Phillips MR, Widrich WC, Johnson WC. Perforation of the inferior vena cava by the Kim-Ray Greenfield filter. Surgery 1980;87:233-5. 11. Wingerd M, Bernhard VM, Maddison F, Towne JB. Comparison of caval filters in the management of venous thromboembolism. Arch Surg 1978;113:1264-71.
Submitted Sept. 12, 1991; accepted Nov. 15, 1991.
Recently interest has been shown in liberalizing the indications for insertion ofvena caval filters. The convenience of percutaneons insertion by radiologists may further perpetuate this trend. However, filter placement is not without morbidity. We report a unique late complication in which a small-bowel obstruction occurred as a result of volvulus around an extruded filter strut. (J VASC SURG 1992;16:113-5.) Deep venous thrombosis (DVT) is a c o m m o n medical problem that affects several million people annually and progresses to pulmonary embolization in an estimated 600,000 cases annually. 1'2 Approximately one third o f pulmonary emboli are fatal. 2 Standard treatment o f both D V T and pulmonary embolism includes the following: bed rest, anticoagulation, and, in some instances, vena caval interruption. The Greenfield filter is currently the most popular method o f caval interruption. Greenfield filters have been in use since 1973. This filter is effective in maintaining a caval patency rate o f 96%, with low procedure morbidity and mortality rates, s T o date, complications related to this filter have been u n c o m m o n and usually are the result o f technical errors at the time o f insertion. Reported complications include embolizatlon caused by the filter,4 proximal migration, 4,5 distal migration, 5 bowel perforation, 6,z structural failure o f the filter, s femoral arteriovenous fistula, 9 and perforation o f the vena cava by the filter struts. 6's'l°'n We report here a case o f penetration o f the vena cava by a filter strut, resulting in a small-bowel obstruction caused by volvulus around this strut.
CASE R E P O R T A 19-year-old white woman was admitted to our trauma center on Sept. 27, 1987, after being struck by a car while walking. She suffered a right hemopneumothorax, a basilar skull fracture with subarachnoid hemorrhage, pelvic From the Department of Surgery, Division of General Surgery, Allegheny General Hospital, Pittsburgh. Reprint requests: Daniel L. Diamond, MD, Director Division of General Surgery, Allegheny General Hospital, 320 E. North Ave., Pittsburgh, PA 15212-9986. 24/4/35062
fractures that required external fixation, a closed right tibial fracture, and a dosed left fibular fracture. Early in her hospital course she had pulmonary emboli documented by pulmonary angiography. Because of the head injury and multiple fractures heparin was contraindicated, and a Greenfield filter was placed via an internal jugular cutdown on Oct. 2, 1987, with the patient under local anesthesia. The postoperative roentgenogram showed the falter at the inferior aspect of the third lumbar vertebral body (Fig. 1). During an orthopedic operation performed 10 days later, with the patient under general anesthesia, the patient had a hypertensive crisis. Urine metanephrine was elevated, and CT scanning showed a periaortic mass. On Nov. 3, 1987, she underwent abdominal exploration and resection of a paraganghoma. The paraganglioma was located on the anterior surface of the aorta at approximately the level of the first lumbar vertebral body. The tumor was located superior to the level of the filter. No effort was made to palpate the filter or locate it during the operation. Postoperative abdominal roentgenography showed no distortion of the filter struts. On Apr. 6, 1989, the patient was admitted with diffuse, severe, crampy abdominal pain. Abdominal roentgenograms supported the clinical diagnosis of small-bowel obstruction and showed distortion of one of the filter struts. At operation, a loop of smaU bowel was "hooked" to the floor of the abdomen by a metal strut from the Greenfield filter. The strut protruded from the anterior wall of the vena cava and through the mesentery. The small bowel had twisted around this point leading to vohaalus. The wire was clipped flush with the cava, and the volvulus was reduced. She was returned to the operating room the following morning for a "second-look" procedure. No bowel was resected. She was discharged on the sixth postoperative day. Six weeks later, the patient was admitted with severe back pain associated with nausea and vomiting. An abdominal roentgenogram showed an ileus as well as fracture of one of the filter struts (Fig. 2). A CT scan of the 113
114
Kupferschmid et al.
Fig. 1. Postoperative roentgenogram after Greenfield filter was inserted via right internal jugular cutdown. Paper clip placed on patient's back before operation for appropriate placement of filter.
abdomen confirmed fracture of one of the filter struts and showed downward migration of the filter hub and the remaining attached five struts, as compared with a previous CT scan of the abdomen. In addition, several struts were thought to be protruding through the wall of the vena cava (Fig. 3). There was no evidence of any paricaval hematoma or mass. At operation, a 10 cm length of the vena cava, which included the filter, was sharply freed from the surrounding tissues. All five of the remaining full-length struts were outside the caval wall for lengths of 1 to 2 cm, including the one that had fractured at the hub. The vena cava was opened, and each of the struts was clipped and withdrawn through the wall of the cava. One of the posterior struts had penetrated into an intervertebral disk space, presumably explaining the presenting back pain. The findings inside of the cava included fracture of one of the struts at the strut-hub juncture. A curtainlike coverage of the struts of the filter against the walls of the vein was noted. The filter was removed, and the cava was closed.
DISCUSSION Vena caval filters have a definite role in the m a n a g e m e n t o f p u l m o n a r y embolus. T h e increased
Journal of VASCULAR SURGERY
Fig. 2. Roentgenogram taken when patient was admitted with back pain. Filter now located at superior aspect of fourth lumbar vertebral body. Note that one filter strut has separated from hub.
case findings o f D V T as a result o f noninvasive venous studies have resulted in insertion o f larger n u m b e r s o f caval filters. T o date, the safety profile o f the Greenfield filter has been admirable. It has been associated with a long-term caval patency o f 9 6 % and has been s h o w n to reduce dramatically the incidence o f fatal p u l m o n a r y e m b o l i s m f r o m sources below the heart. 3 H o w e v e r , filter placement is n o t w i t h o u t complications. We report here a small-bowel obstruction that occurred as a result o f volvulus a r o u n d an extruded filter strut. W h y one o f the struts had penetrated the anterior surface o f the vena cava is not clear. T h e patient had u n d e r g o n e resection o f a periaortic paraganglioma after placement o f the Greenfield filter. A l t h o u g h the t u m o r was located above the filter, it is possible that pressure was placed on the filter during this procedure. An abdominal r o e n t g e n o g r a m obtained after resection o f the manor showed no significant deformity o f the filter. H o w -
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Fig. 3. C o m p u t e d tomographic scan o f the abdomen shows struts protruding through wall of vena cava.
ever, an anteroposterior view may have missed deformity of a strut if it was protruding anteriorly. This patient's small-bowel obstruction was treated by clipping the extruded strut flush with the vena cava and reducing the volvulus. An abdominal roentgenogram obtained after this procedure showed no further deformity of the filter. A C T scan of the abdomen obtained when the patient returned 6 weeks later showed downward migration of the filter and extrusion of the remaining five struts. It is possible that the migration of the filter was related to the fact that one of the struts had been clipped during the operation for the bowel obstruction. SUMMARY Several Conclusions can be drawn on the basis of our experience. First, surgeons must be careful when performing intraabdominal operations on patients with vena cava filters because pressure on the vena cava from retractors may distort the filter. Second, clipping one strut of the filter may make the filter more likely to migrate; therefore, filters should be removed entirely if they cause a significant complication. And finally, extrusion of a filter strut through the anterior wall of the vena cava can result in bowel injury and obstruction. REFERENCES
1. Coon W. Epidemiology of venous thromboembolism. Ann Surg 1977;186:149-64.
2. Dalen JE, Alpert JS. Natural history of puhnonary embolism. Prog Cardiovasc Dis 1975;17:257-70. 3. Greenfield LJ, Michna BA. Twelve-year clinical experience with the Greenfield vena caval filter. Surgery 1988;104:70612. 4. Castaneda F, Herrera M, Cragg AH, et al. Migration of a Kimray-Greenfield filter to the right ventricle. Radiology 1983; 149:690. 5. FriedeU M, Goldenkranz R, Parsonett V, et al. Migration of a Greenfield filter into the pulmonary artery: a case report. J VASC SURG 1986;3:929-31. 6. Sidawy AN, Menzoian JO. Distal migration and deformation of the Greenfield vena cava filter. Surgery 1986;99:36972. 7. Balshi JD, Cantelmo NL, Menzoin JD. Complications ofcaval interruption by Greenfield filter in quadriplegics. J VAsc SuRe 1989;9:558-62. 8. Plaus WJ, Hermann G. Structural failure of a Greenfield filter. Surgery 1988;103:662-4. 9. Grassi CJ, Bettmann MA, Rogoff P, Reagan K, Harrington DP. Femoral arteriovenous fistula after placement of a Kimray-Greenfield filter. AJR 1988;151:681-2. 10. Phillips MR, Widrich WC, Johnson WC. Perforation of the inferior vena cava by the Kim-Ray Greenfield filter. Surgery 1980;87:233-5. 11. Wingerd M, Bernhard VM, Maddison F, Towne JB. Comparison of caval filters in the management of venous thromboembolism. Arch Surg 1978;113:1264-71.
Submitted Sept. 12, 1991; accepted Nov. 15, 1991.
