Bullet migration within the inferior vena cava. (Case Report).

Abstract: We report the case of a patient who sustained gunshot wounds to the chest. The bullet lodged and moved freely within the inferior vena cava and its branches, but the patient had no symptoms. The bullet was retrieved from the right common femoral vein with a basket. Selective approach to bullet removal can prevent serious complications.

Key Words: balloon occlusion, basket, brachiocephalic, bullet, embolization, inferior vena cava, migration, percutaneous, superior vena cava, venotomy

**********

Bullets and bullet fragments have been reported to embolize or migrate to various distant sites after entry into the body. Vascular embolization to sites distant from the point of entry, such as the pulmonary artery or the peripheral arteries, has been reported in the literature. (1,2) In the case reported herein, the bullet entered the upper chest and subsequently lodged within the inferior vena cava (IVC) while the patient remained completely asymptomatic. This bullet changed positions and moved freely within the IVC and the common iliac veins. A MEDLINE search yielded no previous report of similar occurrence. The extraction of this wandering bullet was performed through a venotomy in the common femoral vein after the bullet was retrieved by a basket introduced percutaneously.

Case Report

A 23-year-old man was admitted to the hospital after sustaining two gunshot wounds. One bullet entered the posterior triangle of the neck and was seen on x-ray films to be lodged adjacent to the ipsilateral ramus of the mandible, which had sustained a fracture. The second bullet had entered the back at the level of the T4 vertebra to the left of midline and was seen lying in the right costophrenic recess on a chest film (Figs. 1 and 2). The patient had paraparesis, with sensory and motor deficits below the level of T7-T8. Computed tomography (CT) confirmed that the bullet had traversed the body of T4-T5 and transected the spinal cord, and bony fragments were seen within in the spinal canal. No spine surgery was recommended by the neuro-surgical service. Right-sided pneumothorax was treated by performing tube thoracostomy. Arch aortography with a four-vessel arteriogram and a barium swallow revealed no injuries to the vasculature or the esophagus.

The patient was admitted to the intensive care unit (ICU) and remained hemodynamically stable, with serial hemoglobin measurements showing no apparent bleeding. A chest film obtained the next day showed that the bullet had migrated from the right costophrenic recess (Fig. 3). Fluoroscopic examination revealed the bullet in the right groin. A CT scan obtained immediately thereafter confirmed that the bullet was now in the left common iliac vein (Fig. 4). The CT scan of the chest obtained at admission suggested that the bullet was probably within the PVC just below the right atrium, explaining the position observed on the chest x-ray (Table 1).

Emergency echocardiogram revealed no intracardiac anomalies. A planned interventional approach in which a basket was introduced through the left common femoral vein was unsuccessful in retrieving the bullet. The patient was returned to the ICU and was maintained in a 30-degree upright position. Six hours later, the bullet had migrated to the region of the IVC just below the right atrium, the bullet's original position. Extraction of the bullet was attempted again. This time a larger basket was introduced through the right common femoral vein. The bullet was snared and then delivered into the right common femoral vein (Fig. 5). The bullet was removed through an open venotomy over this site, and then the venotomy was repaired.

Discussion

Bullets entering the chest and major vessels may embolize or migrate. This phenomenon was reported in the literature as early as 1834. (3) Shannon et a1 (4) reported that in 79% of missile emboli, the bullets were small caliber. The proposed hypothesis is that the small bullet penetrates one wall of the vein without penetrating the other and remains intraluminal. These bullets then migrate, either by blood flow or gravity, to a distant point. A heavier bullet's movements within the vascular system may be related more to gravity. An additional requirement for embolization to occur is that the diameter of the bullet must not exceed that of the vessel. The exact route that the bullet took to reach the IVC in this patient is unclear but could be either penetration into the superior vena cava, the brachiocephalic vein, or directly into the IVC. The movement of the bullet within the IVC and both of the common iliac veins suggests that gravity overcame the low venous flow. Reviewing the literature published from 196 6 to 2000 and cited in MEDLINE, we found no reported case of a freely mobile bullet within the IVG. Mattox et a1 (5) reported two cases in which a bullet embolized from the right heart into the TVC and subsequently lodged in the renal vein and the hepatic vein.

Symbas and Harlaftis, (6) in their series of 10 cases, recommended removing all emboli. Mattox et a1 (5) did not propose removal, as evidenced in their series of seven bullets, five of which were left in the pulmonary artery, one of which was left in the hepatic vein, and one of which was left in the renal vein. The potential of bullets lodged in the venous system to embolize is the basis for recommended removal. Numerous reports of delayed embolization support the mandatory removal of intravascular bullets. (7,8) Bullet embolization has also been reported to occur in a retrograde fashion against the normal flow of blood in the venous system. (9,10) Hence, it would be prudent to remove intravascular bullets with the right characteristics-namely, smaller size, anatomic location with a propensity to embolize, and serious consequences if an embolization were to ensue. In our patient, the large size of the bullet warranted its removal, because embolization of the main pulmonary artery could have produced serious effects.

Bullets and other foreign bodies have been retrieved percutaneously through various approaches. Venotomies have been used most often to retrieve bullet fragments. As reported by Gaylord and Johnsrude, (11) however, an Amplatz dilator could be used for percutaneous extraction. Some authors advocate placing a temporary occlusion balloon in the vessel between the heart and the bullet before the actual manipulation of the bullet with a retrieval basket. (12) This method is based on the observation that bullets have a propensity to migrate. (13) In our case, the large size of the bullet precluded percutaneous extraction. In view of the large size and the gravity-aided free mobility of the bullet, the interventional radiologist did not elect to use a temporary occlusive balloon. We were successful in retracting the bullet from the IVC into the common iliac vein and subsequently into the common femoral vein with a basket.

In summary, larger bullets may tend to move with gravity within the venous system. Awareness that bullets can move freely within the vascular system may prevent serious complications, including embolization and ischemia. Selective management in reference to removal of intravascular bullets may be the best option.

Table 1

Course of bullet

Date        Position of bullet             Identification

12/3/00  Right costophrenic recess  Chest x-ray
12/7/00  Right groin                Fluoroscopy
12/7/00  Left common iliac vein     Computed tomography
12/7/00  Upper inferior vena cava   Review of admission CT
12/7/00  Left common iliac vein     Vascular intervention
                                     (unsuccessful)
12/8/00  Right costophrenic recess  Chest x-ray
12/8/00  Bullet retrieved           Vascular intervention through
                                     right common femoral vein

Accepted December 3, 2001

References

(1.) Bemini CO, Junqueira AR Jr, Horita LT, et al. Pulmonary embolism from gunshot missiles. Surg Gynecol Obstet 1983;156:615-619.

(2.) Rich NM, Collins GJ Jr, Andersen CA, et al. Missile emboli. J Trauma 1978;l8:236-239.

(3.) Abad J, Merino MJ, Alted E. Case report: wandering intravascular bullet with aortic pseudoaneurysm. Clin Radiol 1993;47:355-356.

(4.) Shannon JJ Jr, Vo NM, Stanton PE Jr, Dimler M. Peripheral arterial missile embolization: A case report and 22-year literature review. J Vasc Surg 1987;5:773-778.

(5.) Mattox KL, Beall AC Jr, Ennix CL, DeBakey ME. Intravascular migratory bullets. Am J Surg 1979;137:192-195.

(6.) Symbas PN, Harlaftis N. Bullet emboli in the pulmonary and systemic arteries. Ann Surg 1977;155:315-320.

(7.) Adegboyega PA, Sustento-Reodica N, Adesokan A. Arterial bullet embolism resulting in delayed vascular insufficiency: A rationale for mandatory extraction. J Trauma 1996;41:539-541.

(8.) Fisk RL, Addetia A, Gelfand ET, Brooks CH, Dvorkin J. Missile migration from lung to heart with delayed systemic embolization. Chest 1977;72:534-535.

(9.) Schmelzer V, Mendez-Picon G, Gervin AS. Case report: transthoracic retrograde venous bullet embolization. J Trauma 1989;29:525-527.

(10.) Tripp MD, Tisnado J, Bezirdjian DR, et al. Retrograde venous bullet embolization: A rare occurrence. Can Assoc Radiol J 1987;38:292-293.

(11.) Gaylord GM, Johnsrude IS. Split 24-F Amplatz dilator for percutaneous extraction of an intravascular bullet: case report and technical note. Radiology 1989;170:888-889.

(12.) Scalafani SJ, Shatzkes D, Scalea T. The removal of intravascular bullets by interventional radiology: The prevention of central migration by balloon occlusion--Case report. J Trauma 1991;31:1423-1425.

(13.) Scalafani SJ, Mitchell WG. Retrograde venous bullet embolism. J Trauma 1981;21:656-657.

RELATED ARTICLE: Key Points

* Bullets move freely within the vascular system and can result in embolization and ischemia.

* Larger bullets tend to move with gravity.

* Selective management in reference to removal of intravascular bullets may be the best therapeutic option.

* Percutaneous and vascular interventional procedures remain attractive alternatives to direct surgical removal.

From the Department of Surgery, State University of New York at Buffalo, Buffalo, NY.

Reprint requests to Krishnan Raghavendran, MD, Department of Surgery, State University of New York at Buffalo, 462 Grider Street, Buffalo, NY 14215.

Copyright [c] 2003 by The Southern Medical Association 0038-4348/03/9601-0096