LETTERS TO T H E E D I T O R S The Editors invite readers to submit letters commenting on the contents of articles that appear in the Journal. Also welcome are brief communications in 4etter form reporting investigative or clinical observations without extensive documentation and with brief bibliography (five titles or less), not requiring peer review but open to critique by readers. Letters to the Editors should be no more than 500 words in length and they may have to be edited for publication.
~Extended indications for placement o f an inferior vena cava filter
To the Editors:
In a recent issue of the JOURNALOr VASCULARSURGEP,Y Rohrer et al.1 have proposed an extended and more liberal use of the Greenfield inferior vena cava (IVC) filter. ~,The authors report their experiences over a decade with 260 filter placements in 264 attempts, out of which I98 patients underwent the procedure for traditional (.group I) indications and 66 patients for extended indications (group ~, ;: The second group contains 29 patients having neither deep venous thrombosis (DVT) nor pulmonary embolism (PE), i3 patients with DVT, and 24 with documented PE abut without contraindications for anticoagulation in one or the other. The authors are proud to have a low morbidity rate and no mortality in the group of prophyiactic filter placement, whereas the entire series showed a morbidity of 7.9% (air embolism 4, infections 3, vocal cord paralysis 2, malpositions 4, hematomas 6), but three patients (4.5%) had pulmonary embolisms after filter placement with one fatality (1.5% death rate), and documented IVC occlusion *occurred ~ three (4.5%) o f the patients. Because in our department only a single IVC filter had been placed in 10 years, and 330 thrombectomies of the deep venous system were performed during the same time (perioperative mortality 3.3%, recurrent DVT 6%, recurrent PE 1.3%, severe postphtebitic syndrome 5%), we can_ not agree with the authors' conclusion that the IVC falter should be used more liberally. We conclude from our experiences that the best way to manage patients with impending PE is the removal of the documented or potential source of embolism instead of placing an artificial body into the IVC. Alth09gh the morbidity rate in the authors' series may be low, there have ~been, still substantial complications. The rate of long-term effects of these intracaval filters is completely unknown. Only a few follow-up studies exist~,3mostly with large dropout (>50%), and even in the authors' study neither followup period nor number of included patients was mentioned. The single author who seems to be interested in a routine follow-up is L. Greenfield himself, and he pubfished a 30-day mortality rate of 14 0~, a filter misplacement of 3%, and an incidence of late recurrent embolization of 5% (follow-up 99/260 patients, extending to 100 months), Trapped emboli were found in 13%, indicating the efficacy of these devices but likewise that the peripheral thrombosis was still active and caused further emboliza, tion?,* These facts underline the necessity of a routine and permanent anticoagulation despite filter placement for DVT. Although the life-threatening situation even in tra-
ditional cases persists only a short time, Rohrer et al.1 recommended a liberal use of Greenfield filter placement with long-lasting consequences even for patients without PE and DVT. It is very difficult to estimate the risk of PE even in patients with a documented acute DVT, and assessment becomes impossible in patients without any DVT or PE, Vascular surgeons have been criticized for the many prophylactic indications that have been established for reconstructive procedures performed without knowing the natural course o f the disease, and the extended use of an IVC filter is another example for exaggerating the risks of the underlying disease. We cannot agree that improvement of the application techniques and the easiness of filter placement in experienced hands justifies the extended and liberal use. Additonally, it does not seem very logical to place an artifidal material in the venous system if the patient has shown already that he is prone to DVT as a result of coagulopathy. From case reports in the fiteraturC '6 and from our own experiences with patients who had PE and/or DVT after an IVC filter had been placed in other hospitals, we know that the filter can perforate or occlude the IVC and can be the cause for bleeding or embolization. We feel that the filter represents a substantial morbidiw by its own and even the authors themselves report two cases with PE from a thrombus above the previously placed IVC filter. In a recently published study of 100 patients getting a similarly designed device3 the follow-up of 90 cases showed a caval occlusion in seven cases (Z8%) after 1 year, three within 8 days, and four between 3 months and 1 year indicating the permanent influence of these filters in a low flow venous system. It is our o p ~ o n that reports like this one from Rohrer et al.z are dangerous because many physicians underestimate the risk of early and late complications of a permanent IVC filter. These considerations convinced us that the indications for IVC filter implantation in general is too libera[, even in cases of embolizing DVT. Recently we had to remove IVC filters in three patients who developed bleeding and ifiac thrombosis (one) and embolism arid bilateral lilac D V T (two):. Therefore our policy of choice in 103 cases with embolizing DVT was to identify and remove the source of embolization without any additional filter placement. In general in our patients the rate of recurrent embolization (4%) is similar to that reported by Greenfield et al., although half of these cases had a familiar antithrombin-III deficiency. The perioperative mortality rate was 7%, but it could not be attributed to the surgical procedure itself. 105
Journal of VASCULAR SURGF~,Y
Letters to the editor
1. Rohrer MJ, Scheidier MG, Wheeler HB, Cutler BS. Extended indications for placement of an inferior vena cava filter. J VASC SURG 1989;10:44-50. 2. Greenfield LJ. Current indications for and results of Greenfield filter placement. J VASCSURG 1984;1:502-4. 3. Ricco JB, Crochet D, Sebilotte P, et al. Percutaneous transvenous caval interruption with the "LGM" Fiker: early results of a multicenter trial. Ann Vasc Surg 1988;3:242-47. 4. Greenfield LJ, Alexander EL. Current status of surgical therapy for deep vein thrombosis. Am J Surg 985;8:64-70. 5. McAuley CE, Webster MW, Jarrett F, Hirsch SA, Steed DL. The Greenfield intracaval filter as a source of recurrent pulmonary thromboembolism. Surgery 1984;96:574-7. 6. Balshi JD, Cantelmo NL, Menzoian JO. Complications ofcaval interruption by Greenfield filter in quadriplegics. J VAsc SURG 1989;9:558-62. 7. Kniemeyer HW, Sandmann W, Jaeschock R. Thrombektomie mit AV-Fistelbei embolisierender tiefer Venenthrombose - das bessere Therapiekonzept. Langenbecks Arch Chir 1986; 369:603-7.
the results, in patients who receive nonoperative treatment o f DVT where spontaneous venous recanalization frequently occurs. 6 Others have also reported a much higher incidence o f postphlebitic syndrome, 1"7'8which is probably still substantially underreported because o f the long lag time before development o f the severe postphlebitic syndrome.S Perhaps Drs. Kniemeyer and Sandmann's more favor-, able experience relates to careful case selection and other factors that are difficult to ascertain from their brief communication. We encourage them to write a more detailed presentation o f their experience in the J o u I ~ A L oF VASCI_ILARSURGERY for an English speaking audience. Better yet, we would suggest that they organize a prospective multicenter trial with objective documentation of venous patency and venous valxaflar function to verify the excellent results they have reported. Although the removal of thrombus from the deep v ~ nous system is theoretically attractive, we feel that in m ~ ] patients it would prove difficult to remove all the thrombus or prevent its recurrence after thrombectomy. In our experience iliofemoral thrombectomy has proved to be a ~ greater hemodynamic insult with more attendent morbidity and mortality than IVC filter placement. We continue to use the Greenfield IVC filter because o f its extraordinary low risk, even in the critically ill patient. The worries expressed by Drs. Kniemeyer and Sandmann as to the longterm fate o f the Greenfield filter with respect to IVC thrombosis or recurrent embolization have so far proved unsubstantiated in our own experience o f over 350 patients followed up to 12 years, with an average follow-up o f approximately 5 years. We congratulate the authors on their excellent results, but require further definition as to case selection or additional collaboration b e f o r e we can accept that venous thrombectomy is an adequate and safe alternative to I V C filter placement.
A/IichaelJ. Rohrer, BiD Michael G. Scheidler, 341) H. Browndl Wheeler, M D Bruce S. Cutler, M D
These critical remarks come from a traditional country of Europe, where reconstructive vascular surgery began and venous surgery had experienced a renaissance, whereas venous thrombectomy is still being judged as an obsolete procedure in many centers of the United States. O f course this is not a nationalistic difference, but we feel that many new European developments are ignored, probably because of the lack o f communication as a result o f language differences. H. W. Kniemeyer, M D W. Sandmann, M D
Dept. of Vasoalar Surgery and Renal Transplantation Heinrich Heine University Moorenstr. 4 D-4000 Diisseldorf, F.R.G. REFERENCES
To the Editors:
Drs. Kniemeyer and Sandmann suggest that rather than using an IVC filter more liberally, "The best way to manage patients with impending PE is the removal o f the documented or potential source o f embolism." They report 330 deep venous thrombectomies with subsequent pulmonary embolization in only 1.3% o f patients, recurrent D V T in 6%, and severe postphlebitic syndrome in only 5%. These results are much better than previously noted by others who have rep0rted a 5.1% fatal PE rate within the first 2 days ~ e r venous thrombectomy 1 and even a 1.2% rate o f fatal pulmonary emboli intraoperatively.2 Furthermore, others have documented a mean blood loss of 1 L or more requiring transfusion in 92% o f patients. 1'3 Late venograms after venous thrombectomy have shown a 27% to 58% rethrombosis rate with persistent venous obstruction, 2,4,s which is not substantially different from
Division of Vascular Surgery University of Massachusetts Medical Center 55 Lake Ave. N Worcester, MA 01655
1. Lansing AM, Davis WM. Five-year follow-up study of iliofemoral venous thrombectomy. Ann Surg 1968;168:620-8. 2. Andriopoulos A, Wirsing P, Botticher R. Results ofiliofemoral venous thrombectomy after acute thrombosis: report on 165 cases. J Cardiovasc Surg (Torino) 1982;23:123-4. 3. Stephens GL. Current opinion on iliofemoral venous thrombectomy. Am Surg 1976;42:108-15. 4. Einarsson E, Albrechtsson U, Eldof B, Norgren L. Follow-up, evaluation of venous morphologic factors and fimction after thrombectomy and temporary arteriovenous fistula ha throm-