Valvular xenografts in the inferior vena cava.

The unsolved problem of valvular incompetence is a common denominator to chronic venous insufficiency. Cardiac experience with tissue valves suggests the potential for their use in more peripheral locations. The current initial work evaluated 22 valvular xenografts placed in the inferior vena cavas of 22 dogs. Patency extended to 28 months in 12 valves. There was a plausible explanation for failure in 8 of the 10 unsuccessful units. Patent valves functioned with minimal pressure gradients at moderate flow with no evidence of pulmonary emboli. Retrograde valvulograms showed acceptable functional competence in six of eight units examined despite autopsy evidence of leaflet fibrosis and anatomic incompetence. The study establishes the feasibility of long-term patency of valvular xenografts in the inferior vena cava, but also raises questions concerning design requirements for prosthetic venous valves.

Retrieval of intravascular foreign bodies.

The use of intravascular catheters for diagnostic and therapeutic purposes has resulted in an increased number of foreign body embolizations. The retained foreign body is a potential source of morbidity and mortality. In this communication we describe the different techniques that are used to remove foreign bodies from various locations within the heart or vascular tree. A brief review of the literature concerning the reported complications from retained foreign bodies is made to underline the importance of early percutaneous removal of these fragments.

Combined CT metrizamide syringography and needle aspiration of cystic intramedullary spinal cord lesions.

A modified spinal cord puncture technique that was combined with CT metrizamide syringography for the evaluation of potentially cystic spinal cord lesions has been used in 5 patients. This procedure proved to be safe and efficacious in the preoperative differentiation of cystic neoplasms from syringohydromyelia. It also aided in planning a surgical approach by revealing details of the tumor location and/or syrinx dynamics. Spinal cord puncture associated with CT metrizamide syringography has a role in the diagnosis and therapy of patients with cystic spinal cord lesions.

Incompatibility of Hexabrix and papaverine in peripheral arteriography.

A case is reported in which a previously patent artery became temporarily occluded during angiography. The authors believe it happened because of incompatibility of the contrast agent ioxaglate (Hexabrix) and papaverine. Extreme caution is recommended whenever a new low-osmolality contrast agent is used in conjunction with a pharmacoangiographic agent.

Metrizamide shuntography for evaluation of shunt malfunction in hydrocephalus.

Ventricular shunts were evaluated by a shuntographic technique using metrizamide for the contrast material and delayed spot films and computed tomography (CT) to evaluate shunt function. Thirty hydrocephalic patients were studied who had clinical presentations of shunt malfunction. Fifty-two shuntograms were obtained; most demonstrated the cause of shunt malfunction. No contrast-related complications resulted from the procedure. Diagnostic accuracy was greatly improved by this method, since both anatomic and functional evaluations could be performed. In patients with normal studies, unnecessary surgery was eliminated; in abnormal shuntograms, the duration of surgery and the likelihood of complications were reduced because the surgeons knew the exact anatomic derangements to be corrected.

Long-term patency of venous repairs demonstrated by venography.

Indications for venous reconstruction after traumatic injury are controversial, partly because of uncertainty of continued patency. We found no reports in the literature of truly long-term results after venous reconstruction. For clarification of this issue, we reviewed femoral venous injuries in a civilian metropolital population over a 20-year period. There were 31 patients with penetrating femoral venous injuries. Twenty-four patients underwent reconstruction. A search for these patients years after reconstruction located only five patients with six reconstructions. Followup venography at 6 to 20 years demonstrated venous patency and functional valves with asymptomatic patients and no clinical evidence of venous insufficiency in all cases excluding a single 1962 repair with a Teflon graft. This study then supports reconstruction rather than ligation after venous trauma. Although small, this series appears to be the only known report of truly long-term results following venous reconstruction.

Calf hematoma mimicking thrombophlebitis: sonographic and computed tomographic appearance.

Five patients with calf hematomas presented with signs and symptoms suggesting thrombophlebitis, obscuring the correct diagnosis. Venography showed no venous thrombosis; further diagnostic studies using ultrasound and/or computed tomography provided the correct diagnosis in all patients. Ultrasound showed a hypoechoic mass clearly demarcated from surrounding soft tissue, while computed tomography showed a well-defined mass whose density depended on the age of the hematoma.

Thin spinal or biopsy needle guidance.

The thin needles that are used for myelography or biopsy are easily deflected in the body. We describe a simple method used to guide the tip of these needles to the target area using needle-hub rotation. This procedure was successfully used in more than 260 direct C1-C2 punctures for cervical myelography.

Trauma of occult hydronephrotic kidney.

The occult unilateral hydronephrotic kidney is often discovered during the genitourinary evaluation of patients sustaining blunt abdominal trauma. Few cases have been reported documenting the angiographic, computerized tomography (CT), and ultrasound appearances. Two cases are described which demonstrate that relatively minor trauma can precipitate hematuria and hypovolemic shock. Angiography demonstrated the bleeding site in both cases and was utilized in conjunction with other parameters of clinical assessment to plan initial management. CT and ultrasound proved to be useful noninvasive diagnostic parameters for baseline and follow-up studies in patients undergoing conservative management. They accurately demonstrated the degree of hydronephrosis, residual renal parenchymal, and resolving hematoma.

Computed tomography of internal jugular vein thrombosis.

Thrombosis of the internal jugular vein was diagnosed by computed tomography in two cases. On contrast computed tomography, the thrombosed vein appeared as an enlarged vein containing a low density lumen surrounded by a sharply defined wall. This entity should be looked for whenever a patient is examined by computed tomography for acute cervical swelling or inflammatory ear disease.

Venous prosthetic valves. The first step toward an investigation in the canine model.

Bioprosthetic valves were surgically placed in the inferior vena cava of four canines as a first step in the investigation of prosthetic valves for the treatment of nonobstructive chronic venous stasis. Valve patency and thrombus formation involving either the valve or the IVC was evaluated by serial follow-up inferior vena cavagrams in each canine. No thrombus occurred in any of the canines as observed at six months in two canines and eight months in two canines. The ultimate goal of this and other ongoing investigations is to develop a valvular prosthesis which may be placed into the venous system for the management of nonobstructive chronic venous stasis.

Membranous obstruction of the inferior vena cava: an ultrasound, computed tomography, and inferior vena cavogram image correlation.

The purpose of this paper is to present the computed tomography (CT) and ultrasound findings in one case of membranous obstruction of the inferior vena cava (IVC). Although the incidence of membranous obstruction of the IVC is rare in the United States, the diagnosis is essential because of the association of this lesion with portal fibrosis and hepatocellular carcinoma. Membranous obstruction of the IVC is suggested by the findings of a filling defect within the IVC at the level of either the diaphragm or right atrium. Until more specific CT and ultrasound features are described, an inferior vena cavogram will remain the definitive diagnostic procedure for membranous obstruction of the IVC.

Amputation risk factors in concomitant superficial femoral artery and vein injuries.

Only a small subset of patients with combined superficial femoral artery and vein injuries results in amputation. The importance of the venous component as a risk factor for amputation is uncertain. Ligation vs. reconstruction of venous injuries is controversial. For clarification of these issues, we analyzed retrospectively multiple risk factors for amputation in combined superficial femoral artery and vein injuries in a civilian population. There were 25 patients treated in a 20-year period. Sixteen injuries were caused by small caliber missiles, six by shotgun blasts, and three by knife wounds. Three patients (12%) ultimately underwent amputation. The major risk factor for amputation was method of vascular reconstruction. All three amputations underwent ligation of the superficial femoral vein with arterial reconstruction by placement of a reversed interposition saphenous vein graft (p = 0.0009). None of the remaining 22 patients with salvaged limbs underwent reconstruction by this combination of techniques. Consequently, the authors emphasize the importance of venous reconstruction, particularly in combined injuries with major arterial involvement requiring interposed grafts.

Computed tomography of traumatic atlantooccipital dislocation.

Although atlantooccipital dislocation is a well-recognized radiological entity, its computed tomographic (CT) recognition has not been previously described. It is the purpose of this report to show the complementary role of CT in precisely defining the abnormalities in both the coronal and the sagittal reconstruction planes. A case is presented and the literature is reviewed.

Response of an abdominal aortic thrombotic occlusion to local low-dose streptokinase therapy.

Local low-dose streptokinase infusion (5000 to 6000 IU/hr) as compared to systemic streptokinase infusion (loading dose 250,000 IU/hr, maintenance dose 100,000 IU/hr) successfully relieved a total thrombotic abdominal aortic occlusion. No complications of bleeding or distal embolization occurred during streptokinase therapy, which required only 8 days of hospitalization. When seen at 4 months after streptokinase infusion, the patient was still free of symptoms. When no immediate threat of ischemic limb loss exists, streptokinase may offer a promising therapeutic alternative to surgical intervention for patients who represent a poor operative risk.