CT appearance of complications related to thoracic endovascular aortic repair (TEVAR): a pictorial essay.

Thoracic endovascular aortic repair (TEVAR) is a recognized treatment for various diseases involving the thoracic aorta. Patients treated with TEVAR require lifelong surveillance for potential complications, with CT being highly utilized in most centres. Endoleak is the most common complication and can be detected using CT. However, other complications such as stent strut perforations and end organ ischemia can also be detected on CT. The purpose of this pictorial essay is to illustrate the CT appearance of post-TEVAR complications encountered in our institution and to highlight their significance.

Imaging of painful solitary lesions of the sacrum.

In patients with sacral pain, the painful symptoms may be caused by a variety of bony and soft tissue lesions. Benign lesions include giant cell tumour, neurogenic tumour, insufficiency fracture, infection and giant bone island. Malignant lesions include primary bone tumours, Ewing sarcoma, plasmacytoma, lymphoma and chordoma. Soft tissue tumours adjacent to or involving the sacrum may cause painful symptoms. A multimodality approach to imaging is required for full assessment of these lesions. This pictorial essay describes a range of common solitary sacral lesions that may cause pain, with emphasis on imaging features.

Hereditary haemorrhagic telangiectasia with pulmonary arteriovenous malformations: a treatable cause of thromboembolic cerebral events.

Hereditary haemorrhagic telangiectasia (HHT) or Osler-Weber-Rendu syndrome is associated with mucocutaneous telangiectases and iron deficiency anaemia caused by epistaxis or blood loss from the gastrointestinal tract. We describe a 41-year-old Chinese man who presented with amaurosis fugax secondary to emboli from pulmonary arteriovenous malformations associated with HHT. He was diagnosed with the disorder in adolescence but follow-up in the outpatient setting was incomplete. Early screening and regular follow-up of patients with HHT are important to minimise the risk of development of serious sequelae, such as thromboembolic strokes and cerebral abscesses. Appropriate management demands a knowledge of the risks and benefits of asymptomatic screening and treatment in the rapidly-evolving evidence base for this disease.

Preliminary experience in radionuclide therapy of hepatocellular carcinoma using hepatic intra-arterial radio-conjugates.

INTRODUCTION: In a minority of the cases, resection of hepatocellular carcinoma (HCC) is potentially curative but local recurrence is common. Adjuvant intra-arterial radio-conjugate therapy could potentially reduce the rate of local recurrence and increase disease-free and overall survival. However, in the majority of cases, treatment of HCC is largely palliative. A wide range of palliative treatment options are available and these include external radiation, hepatic intra-arterial chemo-embolisation, systemic chemotherapy and percutaneous ethanol injection. The long-term survival rate is poor. Hepatic intra-arterial radio-conjugate therapy provides a new and promising means of palliation. MATERIALS AND METHODS: We share our initial experience in the treatment of patients with HCC. A total of 32 patients were recruited between October 1999 and June 2001. Group 1 comprised 15 patients who had potentially curative resection of HCC who were treated with Iodine-131 (I131) lipiodol as a form of adjuvant therapy. Group 2 comprised 17 patients with unresectable HCC, 12 of whom were treated with Yttrium-90 (Y90) microspheres and 5 with Rhenium-188 (Re188) lipiodol. The radio-conjugates were administered via the intra-arterial route. RESULTS: Thirteen of the 15 patients in group 1 who were treated with I131 lipiodol following curative resection of HCC were free of disease, 1 patient died and 1 patient who developed recurrence was retreated with Re188 lipiodol and was subsequently free of disease. The 6-month disease-free survival rate was 100% and the 12-month disease-free and overall survival rates were 72% and 85%, respectively. Of the 12 patients in group 2 who were treated with Y90 microspheres for unresectable HCC, 6 had stable disease, 2 showed tumour regression and 4 died. The 6-month and 12-month survival rates were 75% and 66%, respectively. Of the 5 patients in group 2 who were treated with Re188 lipiodol for unresectable HCC, 4 had stable disease and 1 had regression of the right lobe tumour but progression of the left lobe tumour. CONCLUSION: Our results in the adjuvant treatment of patients with I131 lipiodol following curative resection of early HCC and in the palliative treatment of unresectable HCC using Y90 microspheres and Re188 lipiodol are preliminary and not fully conclusive. These preliminary results have to be confirmed in larger groups of patients and by prospective, randomised, controlled trials. This study highlights the preliminary experience in radionuclide therapy of HCC using hepatic intra-arterial radio-conjugates in a local context.

Single centre review of radiologically-guided percutaneous nephrostomies: a report of 273 procedures.

INTRODUCTION: To evaluate the technical success and complications associated with radiologically-guided percutaneous nephrostomies (PCNs) in a single centre. MATERIALS AND METHODS: A total of 273 PCNs performed in 190 patients in our hospital over a 3-year period from January 1997 to December 1999 were retrospectively reviewed. The study population consisted of 97 males and 93 females, ranging in age from 13 to 91 years. The main indications were urinary obstruction (77.7%), pyonephrosis (18.3%) and urinary diversion (4%). Demographic variables, technical and risk factors related to the procedure, complications, effect on urine cultures and body temperature; and subsequent patient management were examined. RESULTS: The technical success rate was 99%. The 30-day mortality was 7.2%, none of which were procedure related. Haemorrhage requiring transfusion occurred in 4.3% while septicaemia affected 3.2% of patients. Drainage catheter complications included catheter dislodgement and blockage which were 11.9% and 4.1%, respectively. Thirty-one per cent of PCNs subsequently underwent ureteric stenting as the definitive treatment modality. CONCLUSION: Radiologically-guided PCN is a safe procedure with a high technical success rate.

Clinics in diagnostic imaging (76). Left extradural-intradural lumbar neurofibroma.

A 62-year-old woman presented with weight loss, anoexia and back pain. She was found to have a palpable left abdominal mass. Radiographs, CT and MR imaging revealed a large left 3rd lumbar neurogenic tumour with both intra- and extradural components. A neurofibroma was excised and the diagnosis was confirmed histopathologically. The patient has no recurrence at six years follow-up. The pathological classifications, clinical and imaging features of neurogenic tumours are discussed. With the knowledge of characteristic imaging features, these tumours can be differentiated from other types of intradural-extramedullary tumours.

Radiological placement of 211 central venous catheters: outcome and complications.

A prospective study of 211 central venous catheters consecutively placed in 186 patients under radiological guidance was conducted over an 18-month period. The majority (64%) of our patients were at risk for acute complications or failure. These risks included bleeding tendency, distorted anatomy, or previous complicated lines and failed "blind" percutaneous attempts. We employed the subtraction angiographic technique for venous mapping or ultrasound localisation to guide our initial puncture. The accumulated catheter experience was 15,295 days and the median catheter survival time was 166 days. The success rate was 100%. Our acute complications included 1 case of arterial puncture (0.5%), 2 pneumothoraces (1.0%), and 13 patients (6.1%) with haematoma or prolonged oozing at the puncture site. The calculated infection rate was 0.25 episodes per 100 catheter days at risk. These results are comparable to those reported in the literature. We conclude that central venous catheterisation using imaging guidance is accurate and safe, and should be the method of choice especially in high-risk patients.

Outcome of tunnelled central venous haemodialysis catheters inserted by radiologists.

Radiologists have only recently been involved in the percutaneous placement of tunnelled central venous haemodialysis catheters. We report our initial experience with our first 60 catheters. All catheters were successfully inserted. Immediate complications encountered included puncture site haemorrhage in 3 patients (5%) and puncture of the left brachiocephalic vein in 1 patient (1.7%). These were managed conservatively without any clinical sequelae. About 80% of the catheters were uncomplicated and removed electively. Slightly more than 80% of the catheters were in place for more than 30 days. Infection and blocked catheters were the most common short-term complications. Ten catheters (17%) were infected resulting in premature removal of 9. There was 1 death from presumed line sepsis. Mean duration before the onset of infection was 53 days; the rate of infection was 0.28 episodes per 100 catheter days. Five catheters (8%) were blocked or had poor flow. The mean duration before the onset of blockage was 39 days and the rate of blockage was 0.14 episodes per 100 catheter days. A higher proportion of catheters inserted from the left encountered complications. In conclusion, percutaneous insertion of tunnelled haemodialysis catheters by radiologists is safe and effective. The right internal jugular vein should be the preferred access site. Precautions should be taken to avoid infectious complications given the high rate of catheter removal amongst infected catheters.

Pedicular stress fracture in the lumbar spine.

Spondylolisthesis with or without spondylolysis is common in the lumbar spine. Associated fracture in the pedicle ('pediculolysis') is unusual. The margins of pedicular stress fractures, like spondylolysis, usually appear sclerotic. A patient with a pedicular stress fracture with minimal marginal sclerosis suggesting an injury of recent onset is presented here. There was associated bilateral spondylolysis. The findings in this patient suggest that established pediculolysis probably represents a stress fracture that has failed to heal.

The use of metallic stents in the treatment of malignant superior vena caval obstruction.

Superior vena caval obstruction due to malignancy is conventionally treated by radiotherapy and/or chemotherapy. In patients with unresolved or recurrent obstruction after treatment, expandable metallic stents can be percutaneously placed within the vena cava for relief of symptoms. In this series, metallic stents were successfully deployed in 11 consecutive patients with bronchial carcinoma. Gianturco Z stents were used in 10 patients and Strecker stents in one. There were 2 minor procedural complications of no sequelae. All patients had partial or full relief of symptoms after the procedure. On follow-up (mean 3.9 months), 9 patients had no recurrent symptoms up till the time of death or the present time. Two patients had recurrent obstruction, both within a week of the procedure. Based on our experience, percutaneous stenting was an effective means of palliation in this group of patients when other treatment modalities failed.

Surgical implications of stone impaction in the gall-bladder neck with compression of the common hepatic duct (Mirizzi's syndrome).

Four surgically proven cases of Mirizzi's syndrome are reported and the literature reviewed. The clinical presentation and radiological investigations are described and discussed. All four patients presented with right upper quadrant pain and progressive jaundice. Three patients reported intermittent chills and fever. The percutaneous transhepatic cholangiographic appearances in three cases were diagnostic of this condition. The diagnosis was not made in the fourth case. The important role of the cholangiographer in entertaining the diagnosis and alerting the surgeon to a difficult cholecystectomy is emphasised.