Irreversible electroporation for unresectable hepatocellular carcinoma: initial experience and review of safety and outcomes.

The aims of this study were to evaluate the safety, feasibility and tumour response of _irreversible electroporation, a non-thermal ablation technique, for the treatment of unresectable hepatocellular carcinoma. The endpoints were safety and local treatment efficacy. Patients with unresectable tumours and tumours not amenable for radiofrequency _ablation because of their vicinity to organs vulnerable to thermal damage such as the bowel or because they were close to large blood vessels that would limit efficacy of ablation due to the heat sink effect were treated with irreversible electroporation using percutaneous _ultrasound and/or computed tomography guided electrode placement between November 2008 and _December 2009. Early, late, minor and major complications were recorded. Tumour response was determined on triphasic helical computed tomography follow-up at one month, then every three months post-procedure. Eleven patients received IRE therapy to 18 HCC lesions (Mean diameter 2.44 ± 0.99 cm; range 1.0-6.1 cm) with five patients having more than one treated HCC. Mean follow-up was 18 months (range 14-24 months). Six patients required repeat treatments for local residual or recurrent disease; two of these also had IRE for distant intrahepatic recurrence. No serious complications were observed despite seven lesions lying adjacent to important structures or organs. Four patients developed transient urinary retention and seven developed transient local post-procedure pain. After IRE therapy, 13 (72%) lesions were completely ablated with 93% success for lesions ≤ 3 cm (13/14). The local recurrence-free period was 18 ±â€…4 months and the distance recurrence free period was 14 ±â€…6 months. These preliminary results suggest that IRE is a safe and feasible technique for local ablation of HCC, particularly for lesions less than 3 cm. No major complications were encountered during this study even for tumours close to essential structures or organs.

Initial experience in 115 patients with the retrievable Cook Celect vena cava filter.

The aim of this study was to evaluate our experience with the retrievable Cook Celect inferior vena cava (IVC) filter (William Cook, Europe) with regard to insertion, efficiency, ease of retrieval, and any associated complications. A retrospective review was performed of 115 patients (41 female, 74 male, mean age 47.97 years) who underwent Cook Celect IVC filter insertion between December 2005 and October 2007. Filter insertion was successful in all patients. Of the 115 filters inserted, 57 have been successfully retrieved (49.6%) to date. The successful retrieval rate from attempted retrieval was 93.4%. The mean dwell time of successfully retrieved filters was 114.9 days (range 14-267 days). Failed retrievals were due to a thrombosed vena cava (n = 1) and endothelialisation of the filter (n = 3). In the failed retrieval group the mean implantation time was 142 days (range 78-211 days). While this is the first retrospective clinical study on the Cook Celect filter, results to date are promising. We demonstrated an efficacious filter with a high successful retrieval rate of 93.4% and a low complication rate. The filter was assessed with extended dwell times (range 14-267 days). Failed retrieval secondary to hook endothelialisation continues to be an issue with this filter. We recognize that a limitation of our study was the lack of systematic follow-up for clinically silent complications. Further studies to evaluate longer term outcomes and effectiveness of this filter are warranted.

Radiation exposure and the justification of computed tomography scanning in an Australian hospital emergency department.

In an emergency department (ED), computed tomography (CT) is particularly beneficial in the investigation of high-speed trauma patients. With the advent of multidetector CT (MDCT) scanners, it is becoming faster and easier to conduct scans. In recent years, this has become evident with an increasing number of CT requests. Patients who have multiple CT scans during their hospital stay can receive radiation doses that have an increased theoretical risk of induction of cancer. It is essential that the clinical justification for each CT scan be considered on an individual basis and that due consideration is given to the radiation risk and possible diagnostic benefit. The current lack of a central State or Commonwealth data repository for medical images is a contributing factor to excessive radiation dosage to the population. The principles of justification and radiation risks are discussed in this study.

Retrievable Gunther Tulip inferior vena cava filter: experience in 317 patients.

The aim of our study was to assess our experience with the retrievable Gunther Tulip (GT) inferior vena cava (IVC) filter, with regard to its insertion, efficacy, ease of placement and retrieval, and associated complications. Between November 2001 and October 2005, 322 GT filters were placed in 317 patients. Insertion indications included the following: pulmonary embolus (PE) prophylaxis in trauma patients (n = 232), PE prophylaxis in perioperative patients (n = 27), PE prophylaxis in moribund intensive care unit patients (n = 22), recent PE (n = 48), extensive deep venous thrombosis (n = 66), contraindication to anticoagulation (n = 63), anticoagulation complication (n = 8) and deep venous thrombosis with failed anticoagulation (n = 8). Some patients had more than one indication for caval filter placement. Two hundred and five attempted retrievals have been carried out, with 15 failures. Our successful retrieval rate is 92%. Nineteen filters were originally inserted permanently. There have been three minor complications associated with insertion and five with retrieval. The mean time from filter insertion to attempted retrieval was 76.95 days. The ideal filter implantation time gives the patient the benefit of PE protection, while avoiding the long-term risks associated with caval filters. Although GT retrieval times have lengthened considerably, our data suggest that this is at the expense of successful retrieval rates.

Embolization of spontaneous hemarthrosis post total knee replacement.

Spontaneous nonhemophiliac hemarthrosis is an unusual entity, which has been little described. We present three cases of spontaneous recurrent hemarthrosis post total knee replacement (TKR) and successful management with embolization. Three male patients were referred to our service for angiography and treatment of recurrent hemarthrosis post TKR. In all three patients antegrade ipsilateral common femoral artery punctures and selective angiography of the geniculate branches were performed with a microcatheter. Abnormal vasculature was noted in all cases. Subsequent embolization was performed with Contour (Boston Scientific, Target Vascular, Cork, Ireland) embolization particles (150-250 and 250-355 microm) in two patients and microcoils in the third (TornadoR; Cook Inc., Bloomington, IN, USA). Technical success was 100%. One patient had a recurrence of symptoms requiring a repeat procedure 6 months later. No complications were encountered. Selective angiography and particle embolization is an effective technique for management of this unusual but problematic postoperative sequelae.

Endovascular treatment of arterial mesenteric ischaemia: a retrospective review.

Mesenteric ischaemia is a condition that has traditionally been managed surgically. It poses a challenging diagnostic and therapeutic problem, particularly in the acute setting. We review a small series of eight patients managed with endovascular techniques for either acute or chronic mesenteric ischaemia at The Royal Melbourne Hospital, from 1997 to 2002. We describe our results and relate these to the recent published literature regarding endovascular and surgical management of mesenteric ischaemia. Our experience confirms the valuable contribution of angioplasty and stenting in chronic mesenteric ischaemia, which compares favourably with surgery with regards to complication rates and mortality. We suggest the need for further studies to compare the long-term efficacy of endovascular techniques compared with surgery in the management of chronic mesenteric ischaemia. Furthermore, we demonstrate a role for endovascular management in acute mesenteric ischaemia, in the appropriate clinical setting.

Angioplasty and stenting of the superior mesenteric artery in acute mesenteric ischaemia.

Acute mesenteric ischaemia is a challenging diagnostic problem with a very high mortality. Traditionally, laparotomy is required for definitive management. We describe a successful case of angioplasty and stenting of the superior mesenteric artery in a surgically unfit patient. We recommend that stenting be considered only in situations where the diagnosis has been made prior to bowel infarction, and if the patient poses a poor operative risk.

A complicated percutaneous coil embolisation of a large coronary artery fistula.

A coronary artery fistula is a rare cause of cardiac symptoms or signs in an adult. We report here the successful percutaneous treatment of a large fistula in an adult who had suffered an acute myocardial infarction peri-operatively due to a steal phenomenon. Due to the fistula size, a specially constructed occlusion device was utilised for effective treatment.

Manometry combined with cervical puncture in idiopathic intracranial hypertension.

OBJECTIVE: To determine by cerebral venography and manometry in patients with idiopathic intracranial hypertension the cause of the previously demonstrated venous hypertension in the superior sagittal and proximal transverse sinuses. METHODS: Cerebral venous sinus pressure was measured before and immediately after C1-2 puncture with removal of 20 to 25 mL of CSF. RESULTS: Lowering the intracranial pressure by lateral C1-2 puncture during manometry has shown that the venous hypertension resolves immediately. CONCLUSION: These studies indicate that the venous hypertension is due to compression of the transverse sinuses by raised intracranial pressure and not due to a primary obstructive process in the cerebral venous sinuses.

Tandem lesions of the carotid circulation: combined extracranial endarterectomy and intracranial transluminal angioplasty.

A case series is presented demonstrating a unique approach to the treatment of tandem atherosclerotic lesions of the internal carotid artery. Between 1994 and 1999 eight patients with tandem lesions of the internal carotid artery were treated by combined carotid endarterectomy for the proximal lesion and intraoperative angioplasty of the distal intracranial lesion via the carotid arteriotomy. The success and complication rates were evaluated. A 100% technical success rate was achieved with one post procedural complication by ipsilateral stroke within 24 h. The advantages of this technique include the treatment of tandem lesions by the one procedure, improved transluminal access to the intracranial lesion and the ability to reduce the risk of embolism by flow control during balloon inflation.

Treatment of renovascular disease with percutaneous stent insertion: long-term outcomes.

Renal artery stenosis is a common, progressive cause of hypertension and renal impairment, and is frequently treated with percutaneous transluminal dilatation and stenting. The outcome of this procedure is still being evaluated. The records of 198 consecutive patients who had stents inserted at the Royal Melbourne Hospital were analysed retrospectively, and adequate follow-up information on 148 (75%), in whom a total of 182 renal arteries had been treated was obtained. Technical success was achieved in 144 patients (97%). Complications occurred in 19 patients (13.3%), with major complications occurring in 10 (7.0%) and one death occurring in relation to the procedure. A fall in average systolic blood pressure of 13.2 mmHg (12.1-14.3 mmHg) was seen and a fall in diastolic blood pressure of 10.1 mmHg (9.3-10.9 mmHg), without an increase in the number of antihypertensive drugs used. Renal function remained stable in the majority of patients, particularly those who had minimal baseline renal impairment. Restenosis was common after 6 months, occurring eventually in 29% of screened patients, but was not shown to affect clinical outcomes. Insertion of renal artery stents is a safe and effective treatment for renal artery stenosis.

MR imaging of renal masses interpreted on CT to be suspicious.

OBJECTIVE: Prior studies have shown that renal MR contrast enhancement improves the efficacy of mass and proximal vascular evaluation. This study assessed the usefulness of different sequences for characterization of masses that appeared suspicious on CT and for prediction of their potential for malignancy. SUBJECTS AND METHODS: In a prospective manner 32 patients (age range, 26-78 years: average age, 54 years), each with at least one suspicious mass on CT, were examined with MR imaging. The following sequences were performed: conventional spin-echo with and without fat saturation, fast spin-echo, and dynamic gadopentetate dimeglumine-enhanced infusion using a 1.5-T superconducting magnet. Results were analyzed and compared with pathologic results after resection. RESULTS: A total of 65 renal masses of average size 2.6 cm (range, 1-10 cm) were detected with dynamic MR imaging. Seventeen of the 65 masses were malignant. Of the 17 malignant masses, three did not enhance on dynamic MR imaging (because of hemorrhage). Sixteen of the 17 malignant masses were heterogeneous on T2-weighted images. Three enhancing masses contained fat and all were angiomyolipomas. Thirty-five of the 65 masses (four with hemorrhage) did not show enhancement, all of which were homogeneous on T2-weighted images and were proven to be cysts. Five masses resulted from infections and had heterogeneous T2 appearance. The remaining masses were three hematomas with hemorrhage, one column of Bertin, and one aneurysm. CONCLUSION: Renal masses that are interpreted as suspicious on CT may lack MR enhancement because of hemorrhage effects; heterogeneity of their T2 appearance is thus critical in differentiating malignancy from benign disease. Odds-ratio calculations give an adjusted estimate of a 3.36-fold increase (95% confidence interval, 1.8-6.27) in the likelihood of malignancy when masses are heterogeneous on T2-weighted images and a 29-fold increase (95% confidence interval, 3.67-241.8) for predicting malignancy when enhancement is present.

Doppler ultrasound (pre- and post-contrast enhancement) for detection of recurrent stenosis in stented renal arteries: preliminary results.

The purpose of the present paper was to assess whether conventional renal Doppler ultrasound and the commonly used parameters of peak systolic velocity and renal aortic ratio may be an appropriate modality for the follow-up of renal artery stents. A total of 19 arteries in 15 patients was examined with both renal Doppler ultrasound and angiography for the presence or absence of recurrent renal artery stenosis. Disease was considered present on angiography if the arterial diameter was more than 60% stenotic. Doppler criteria for stenosis were either a peak systolic velocity of > 180 cm/s or a renal aortic ratio of > 3.0. Echo enhancement with Levovist (Schering, Berlin, Germany) was used if studies were technically unsuccessful or to improve diagnostic confidence. Renal Doppler ultrasound detected 100% of renal artery stenoses. The specificity was 75%, the positive predictive value was 67% and the negative predictive value was 100%. Echo enhancement improved the technical success rate from 89 to 95% and also increased diagnostic confidence in six examinations. The present limited study suggests that similar renal Doppler parameters as used for the study of unstented renal arteries may be applied to the examination of renal arteries with renal stents in situ. It therefore suggests that Doppler ultrasound may provide an adequate non-invasive means of renal artery stent follow-up, particularly when combined with echo-enhancing agents. Further study is warranted to confirm these initial conclusions.

The Erasme study: a multicenter study on the safety and technical results of the Palmaz stent used for the treatment of atherosclerotic ostial renal artery stenosis.

PURPOSE: To assess, in a multicenter setting, safety, technical results, and restenosis rate of the Palmaz stent for treatment of atherosclerotic ostial renal artery stenosis. METHODS: Ten centers enrolled 106 patients (120 treated renal artery stenoses) in the study. Patient selection was based on unsuccessful percutaneous transluminal renal angioplasty (residual stenosis >/= 20%) performed for treatment of ostial stenosis >/= 50%, in patients with hypertension and/or impaired renal function. Safety was assessed by means of the complication rate, and technical results by the number of successful stent placements and occurrence of restenosis (>50%) at intraarterial angiographic follow-up. RESULTS: Stent placement was successful (n = 112) or partially successful (n = 5) in 117 (98%) arteries. Complications occurred in 19 procedures; seven were of serious clinical significance. Angiographic follow-up was performed in 89 of 117 (76%) cases, at a mean of 8 months (range 2. 5-18 months). Fifteen stents (16.9%) showed restenosis (at a mean of 8.5 months), of which 10 were successfully redilated. CONCLUSION: Renal artery stenting has a high technical success rate, a complication rate comparable to percutaneous transluminal renal angioplasty, and a low rate of restenosis at 8 months angiographic follow-up.

Treatment of infrarenal aortic stenosis by stent placement: a 6-year experience.

There is a significant re-stenosis rate with percutaneous treatment of stenoses of the infrarenal abdominal aorta with balloon angioplasty. Since 1990 the authors have primarily treated local infrarenal aortic stenoses with metallic endoluminal stents. The authors' experience with 12 consecutive patients (nine women and three men, aged from 30 to 72 years (mean age = 57 years)) is presented. Follow-up is available in 11 cases over 7-78 months (mean 32 months). The procedure was technically successful in all patients. Of the 11 patients with follow-up available, claudication was cured (n = 7) or significantly improved (n = 4). Those with persisting claudication had concurrent distal arterial disease. Periprocedural complications occurred in five cases, with two significant complications. One case required iliac angioplasty for embolized aortic atherosclerotic plaque, and one case required surgical thrombectomy and vein patch for iliac thrombosis complicating iliac dissection, without long-term sequelae in either case. One patient has had recurrent symptomatic aortic stenosis occurring 6 years after initial stenting, which responded to further stent insertion. Primary patency of 91% and secondary assisted patency of 100% has been achieved. Primary treatment of infrarenal aortic stenosis with endoluminal stenting results in high patency rates, with low morbidity and relatively low complication rates.

Complication of a venous wallstent.

A case is reported here of effort-related thrombosis of the axillary and subclavian veins (Paget-Schrotter syndrome) treated primarily with a combination of thrombolysis, percutaneous balloon angioplasty (PTA) and stent insertion, but without immediate rib resection. The subsequent course was complicated by fracture of the stent, managed by first rib resection.

Interventional catheter magnetic resonance angiography with a conventional 1.5-T magnet: work in progress.

Magnetic resonance contrast enhancement depends on the relative timing of image acquisition. Limited human trials have demonstrated efficacy of intra-arterial gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) in delineating vascular anatomy with X-rays. The present study assessed the ability of dynamic MR during intra-arterial Gd-DTPA administration to demonstrate vascular anatomy compared to conventional angiography as the gold standard. As interventional MR techniques using dedicated magnets proliferate, the ability to perform invasive MR angiography with a conventional magnet would be of great utility at established sites. Four subjects referred for different types of angiography underwent dynamic MR studies, including one with iliac artery stenting (Palmaz P204, Johnson and Johnson). All were examined with conventional angiography, and again after dynamic intra-arterial (IA) Gd-DTPA infusion. Coronal MRI images of the body were acquired using a 1.5-T superconducting magnet (three with a GE Signa, one with Philips NT), fast spoiled gradient echo (FSPGR); echo time (TE) = 4.2 msec, repetition time (TR) = 68-150 msec, flip = 75 degrees, 0-600 s after dilute Gd-DTPA IA bolus injection during sequential breath-hold acquisitions of 13-32 s each. All arteries were detected with dynamic MR. The FSPGR MRI with IA Gd-DTPA administration can provide adequate time and spatial resolution to demonstrate arterial anatomy and arterial stent patency.

Stenting in malignant and benign vena caval obstruction.

Expandable metallic stents have been used with considerable success for the palliation of malignant vena caval obstruction. The role of stenting in vena caval obstruction of benign aetiology is less well defined. A review of 11 patients stented for vena caval obstruction and a review of recent series in the literature is presented. Of the 11 patients, seven patients had involvement of the superior vena cava (SVC), and four patients had inferior vena caval (IVC) obstruction. Seven cases had malignant vena caval obstruction, with a benign aetiology (SVC n = 3; IVC n = 1) in the other four cases. All seven patients treated with SVC stents experienced complete resolution or significant improvement in symptoms with no recurrence over the duration of available follow-up, over an average of 4.3 months (range: 1 week-12 months). Only one of four IVC lesions stented resulted in a good clinical response. All four patients with vena caval obstruction of benign aetiology had a good outcome. One patient experienced a small pulmonary embolus following SVC stent insertion without further sequelae. No other serious complications were encountered. Stenting can provide prompt relief of vena caval obstruction with low morbidity, and high patency rates in both benign and malignant vena caval lesions.