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February 2012, Volume 62, Issue 2

Letter to the Editor

Dilemma of indiscriminate use of Vena Cava filters

Madam, mechanical interruption of blood flow by femoral vein ligation as a means to protect against pulmonary embolism (P.E.) was first performed by John Hunter in 1784.1,2 Mobin-Uddin a Pakistani Vascular Surgeon was the first to introduce intra-luminal device in 1967.3 However, the earlier umbrella devices had a significant thrombosis and migration rate. In 1973, the Greenfield filter was introduced which could be inserted percutaneously and have received wide success.
The practice of Inferior Vana Caval (IVC) Filter insertion has significantly changed over the years. There has been multifold increase in IVC filter insertion over the last two decades, due to ever expanding indications.4 The ease of insertion via percutaneous methods along with introduction of newer retrievable devices might also be responsible for these increased rates. This has occurred despite the evidence that only a proportion of retrievable filters are actually retrieved.5 The IVC filter was initially placed in patients with contraindication or complication to anticoagulation but now it\'s being placed for patients with embolism having poor cardiopulmonary reserve, free floating clot, in trauma patients with multiple injuries who despite of being a high risk of embolism cannot be given anti-coagulation, as pre-operative prophylaxis in selected individuals and in patients who are non-compliant with anticoagulation.6
The cost of filter placement in USA ranges from 1265- 1703$ (approx PKR 126,140. on average) depending on which brand was used.7 Retrievable filters are more expensive than permanent filters and from a financial point of view situation is even more worrisome since they don\'t get retrieved in vast majority of cases. Even more astonishing is the suggestion that insertion of an IVC filter provides little or no survival benefit in high-risk patient\'s categories i.e. advanced malignancy.8
Currently there is no data available on the burden of thromboembolism in out patient population. The prevailing belief that thromboembolism in Asian population is less than in the Western population has essentially been disproved.9,10 Rapid industrialization and an increase in life expectancy suggest that the incidence will continue to grow in the years to come. Although IVC filters are being placed in increasing numbers in Subcontinent and neighbouring countries, resource constraints has lead to limited applications of healthcare guidelines developed for western nations.11 It is now more important than ever for low income countries to come together and develop a common ground for establishing guidelines and protocols to practice economically feasible and culturally compatible therapeutic modalities.
In sum, despite the increasing utility of IVC filter over the past 30 years, controversy regarding their appropriateness continues. Although, filters can now be placed with minimal procedure or filter related complication compared with historical controls, we recommend thorough consideration on case-to-case basis. When retrievable filters are pursued plan regarding the timing of retrieval should be clear to patient and all involved providers. We also feel that filter placement in sicker patients should be withheld since it has not shown mortality benefit and might add to morbidity.
 
Mian Muhammad Rizwan, Maria Zulfiqar
Department of Internal Medicine, Prince George\'s Hospital, USA.

Reference

1.Greenfield LJ. Evolution of venous interruption for pulmonary thromboembolism. Arch Surg 1992; 127: 622-6.
2.Hunter J. Observations on inflammation of internal coat of veins. Trans Soc Improvement Med Chir Knowledge 1793; 1: 18.
3.Dodson MG, Mobin-Uddin K, O\'leary JA. Intracaval Umbrella-Filter for Prevention of Recurrent Pulmonary Embolism. Southern Med J 1971; 64: 1017-8.
4.Stein PD, Kayali F, Olson RE. Twenty-one-Year Trends in the Use of Inferior Vena Cava Filters. Arch Intern Med 2004; 164: 1541-5.
5.Karmy-Jones R, Jurkovich GJ, Velmahos GC, Burdick T, Spaniolas K, Todd SR, et al. Practice Patterns and Outcomes of Retrievable Vena Cava Filters in Trauma Patients: An AAST Multicenter Study. J Trauma 2007; 62: 17-25.
6.Hammond CJ, Bakshi DR, Currie RJ, Patel JV, Kinsella D, McWilliams RG, et al. Audit of the use of IVC filters in the UK: experience from three centres over 12 years. Clin Radiol 2009; 64: 502-10.
7.d\'Othée BJ, Faintuch S, Reedy AW, Nickerson CF, Rosen MP. Retrievable versus Permanent Caval Filter Procedures: When Are They Cost-effective for Interventional Radiology? J Vasc Interv Radiol 2008; 19: 384-92.
8.Schunn C, Schunn GB, Hobbs G, Vona-Davis LC, Waheed U. Inferior Vena Cava Filter Placement in Late-Stage Cancer. Vasc Endov Surg 2006; 40: 287-94.
9.Dhillon KS, Askander A, Doraisamy S. Postoperative deep-vein thrombosis in Asian patients is not a rarity: A prospective study of 88 patients with no prophylaxis. J Bone Joint Surg Br 1996; 78: 427-30.
10.Leizorovicz A, Turpie AGG, Cohen AT, Wong L, Yoo MC, Dans A, et al. Epidemiology of venous thromboembolism in Asian patients undergoing major orthopedic surgery without thromboprophylaxis. The SMART Study. J Thromb Haemost 2005; 3: 28-34.
11.Ahmed W, Mehmood M, Akhter N, Shah MA. Role of inferior vena cava filter implantation in preventing pulmonary embolism. J Coll Physicians Surg Pak 2007; 17: 350-2.

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