David J. Allison

Treatment of high-flow vascular malformations by venous embolization aided by flow occlusion techniques

PurposeTransvenous embolization techniques may be helpful as alternatives to the arterial route when treating high-flow vascular malformations. We present our experience using these techniques in four patients.MethodsIn one patient the venous portion of the arteriovenous malformation (AVM) was punctured directly; in the other three patients it was catheterized via a retrograde venous approach. Flow occlusion techniques were utilized in all patients during embolization, which was performed with absolute alcohol orN-butyl-2-cyanoacrylate.ResultsExcellent clinical and angiographic results were obtained, with obliteration of arteriovenous shunting in all patients. There were no complications.ConclusionThe embolization of certain AVMs using a venous approach is a safe and effective treatment.

Quantification of right to left shunt through pulmonary arteriovenous malformations using 99Tcm albumin microspheres

Calculation of the right-to-left shunt through pulmonary arteriovenous malformations (PAVMs) is important in assessing the effect of therapeutic embolisation or surgical resection. Previously, complicated physiological techniques using radiolabelled inert gases or the 100% oxygen breathing method were required. We describe a new method for quantitating the systemic uptake of intravenously injected 99Tcm albumin microspheres (99Tcm MS) which reflects shunt fraction since these particles do not normally traverse the pulmonary capillary bed. Seven patients with PAVMs were studied and shunt values obtained using 99Tcm MS were validated by simultaneous measurement of shunt fraction using the 100% oxygen method. By comparing radioactive counts in the injection dose to subsequent counts in the right kidney, which was taken as an index of systemic activity, accurate quantification of right-to-left shunt over a wide range of values was obtained (correlation coefficient against 100% oxygen method r = 0.993). The comparison of right kidney counts with total lung counts and total lung counts with injected dose counts, also indicators of shunt fraction, correlated less well with the oxygen method (r = 0.942 and r = 0.88 respectively). Use of 99Tcm labelled microspheres allows simple and precise measurement of right-to-left shunt in patients with PAVMs during routine isotope lung scanning.

Percutaneous transhepatic endoprostheses for hilar cholangiocarcinoma

In patients with unresectable hilar cholangiocarcinoma, percutaneous transhepatic endoprosthesis insertion is one of the available methods of palliation. We reviewed our experience with it in 35 consecutive patients with hilar cholangiocarcinoma who were judged on clinical or radiologic evidence to be unsuitable for resective or palliative surgery. The 30-day mortality rate was 14 percent (5 of 35 patients). Of the remaining 30 patients, endoprosthesis placement was successful in 28, with 2 patients discharged with a permanent external drainage catheter. Twenty-four patients survived a median of 3 months (range 1 to 17 months), and 2 were lost to follow-up. Good or fair palliation of symptoms was achieved in 50 percent of the discharged patients and in 66 percent of those living longer than 3 months. We believe that percutaneous transhepatic endoprostheses can provide useful palliation in patients with hilar cholangiocarcinoma, even in the presence of advanced disease.

The radiology of fibrolamellar hepatoma

Seven patients with fibrolamellar hepatoma were examined with computed tomography (CT), ultrasonography and angiography. On CT the tumours were large, of low attenuation, had a well-defined edge and some contained areas of calcification or necrosis. Ultrasonography revealed well-defined masses of mixed echogenicity, occasionally involving the portal vein. In one patient there was dilatation of the intrahepatic biliary tree. Arteriography showed vascular tumours with involvement of the portal vein in five cases and compression of the inferior vena cava in five cases. CT and ultrasonography are the most useful radiological investigations for suggesting the diagnosis of fibrolamellar hepatoma which should be considered in the case of any large solitary well-defined hepatic tumour in the noncirrhotic liver of a young person.

Case Report: Jejunal Vascular Malformation in Klippel-Trenaunay Syndrome

We report a case of Klippel-Trenaunay syndrome who presented with a long history of gastrointestinal (GI) blood loss and was shown to have an extensive vascular malformation in the small bowel.

Arterial embolization in the management of liver metastases

Hepatic arterial embolization has been shown to be a safe and effective method for the palliation of symptoms in patients with metastatic disease, particularly those with secondary deposits from endocrine tumors. This review examines the indications for the procedure, discusses some aspects of technique, and assesses the potential benefits and complications of the method.

Use of giant steel coils in the therapeutic embolization of a superior mesenteric artery-portal vein fistula

The use of a series of giant steel coils is described for the therapeutic embolization of a posttraumatic arteriovenous fistula between the superior mesenteric artery and the portal vein.

Wallstent endoprostheses for the relief of prostatic urethral obstruction in high risk patients

Twenty-one patients with prostatic urethral obstruction who were unfit for surgery were treated with self-expandable stainless steel endoprostheses inserted under fluoroscopic guidance. The procedure was technically successful in all patients, although in one case a second stent was required 2 months later. One patient developed a urethral stricture in the 12-16 month follow up period. One case of epididymoorchitis and one case of septicaemia after stenting were treated successfully with antibiotics. Endoprostheses represent a satisfactory alternative to prostatectomy in high-risk patients.

Therapeutic arterial embolisation of the spleen: a new cause of free intraperitoneal gas

Case histories of two patients are presented in whom splenectomy was required for haematological disorders, but because surgery was contraindicated had therapeutic arterial embolisation of the spleen performed as an initial alternative. A significant improvement in the haematological state was achieved in both cases but one of the patients required drainage of a splenic abscess three months later. In both patients the embolisation caused the early appearances of extravascular gas in the spleen and in one patient a pneumoperitoneum also occurred. The possible aetiological factors involved in this phenomenon are discussed, together with the potential role of splenic embolisation. It is concluded that therapeutic embolisation may be a useful alternative to splenectomy in selected poor-risk patients, but carries a significant risk of inducing a splenic abscess. Intrasplenic or intraperitoneal gas may appear as an apparently benign incidental finding in the early post-embolisation period.

Pre-operative embolisation of a chemodectoma

Surgical removal of a large carotid body tumour can be difficult and hazardous because the tumours are extremely vascular. We present a case in which preoperative embolisation of such a tumour facilitated subsequent surgery. The case also illustrates a technique for protecting vascular territories outside the embolisation field from inadvertent embolisation.