Israel Medical Association Journal

Background: Radiofrequency ablation has been suggested as first-line therapy in the management of accessory pathways. There are limited data on the results of ablation over years of experience.

Objectives: To assess the results and complications following RFA[1] of APs[2] performed in our institution over a 14 year period.

Methods: RFA was performed using deflectable electrode catheters positioned at the mitral or tricuspid annulus. The site of the AP was localized by electrophysiological study and radiofrequency energy was applied via the tip of the catheter

Results: The study cohort comprised 508 consecutive patients (64.2% males, mean age 33.6 ± 15.1 years) who underwent 572 RFA procedures for ablating 534 APs. A single AP was found in 485 (95.5%) patients while multiple APs were noted in 23 patients (4.5%). The APs were manifest, concealed or intermittent in 46.8%, 44.4% and 8.8% of cases, respectively. AP distribution was as follows: left free wall (56.6%), posteroseptal (23%), right anteroseptal (7.9%), right free wall (6.2%), midseptal (3.4%) and right atriofascicular (3.0%). Acute successful rates for a first or multiple ablation attempts were 93.1% and 95.3%, respectively. At a first ablation attempt, acute success and failure rates were the highest for midseptal (100%) and right atriofascicular (12.5%) APs respectively. Right anteroseptal APs were associated with the highest rate (23.9%) of discontinued or non-attempted procedures. Recurrent conduction in an AP after an initial successful ablation was observed in 9.9% of cases; it was the highest (24.2%) for right free wall APs and the lowest (5.0%) for left free wall APs. During follow-up (85 ± 43 months), definite cure of the AP was achieved in 94.9% of cases following a single or multiple procedures: midseptal (100%), left free wall (98%), right free wall (97%), posteroseptal (92.7%), right atriofascicular (87.5%) and right anteroseptal (78.5%). A non-fatal complication occurred in 18 patients (3.5%), more frequently in females (6.6%) than in males (1.8%) (P < 0.01). The two major complications (pericardial effusion and myocardial ischemic events) mainly occurred during RFA of a left free wall AP using a retrograde aortic approach. Catheter-induced mechanical trauma to APs was observed in 56 cases (10.5%). Mechanical trauma mainly involved right atriofascicular (43.8%) and right anteroseptal (38.1%) APs and contributed to the low success rate of RFA at these AP locations. During the 14 year period, our learning curve was achieved quickly in terms of success rate, although the most significant complications were observed at the beginning of our experience.

Conclusions: The results of this study confirm the efficacy and safety of RFA and suggest that it is a reasonable first-line therapy for the management of APs at any location.

Objectives: To report a 14 year experience of RFA[2] of the slow pathway in patients with AVNRT treated in our laboratory.

Methods: A total of 901 consecutive patients (aged 9–92, mean 50.8 ± 18.2 years) underwent RFA of the slow pathway. All patients had sustained AVNRT induced with or without intravenous administration of isoproterenol. A standard electrophysiologic method with three diagnostic and one ablation catheter was used in 317 patients (35.2%); in the remaining 584 patients (64.8%), only two electrode catheters (one diagnostic, one ablation) were used ("two-catheter approach").

Results: Catheter ablation of the slow pathway abolished AVNRT induction in 877 patients (97.3%). In 14 patients (1.6%) the procedure was discontinued while in 10 (1.1%) the procedure failed. In 864 patients (95.9%) there were no complications. Transient or permanent AV block occurred during the procedure in 31 patients (3.4%), of whom 8 (0.9%) eventually required pacemaker insertion (n=7) or upgrade of a previously implanted VVI pacemaker (n=1) during the month following the procedure. The number of catheters used did not significantly affect the rate of results or complications of the ablation procedure. The success and complication rates remained stable over the years, although a significant trend for increased age and associated heart disease was observed during the study period.

Conclusions: The results of this single-center large study, which included patients with a wide age range, showed results similar to those of previous studies. The use of a "two-catheter approach" (one diagnostic and one ablation) was as effective and safe as a multi-catheter approach.

Background: Idiopathic left ventricular tachycardia with a right bundle branch block configuration and left axis deviation, first described by Belhassen et al., is a rare electrocardiographic-electrophysiologic entity. Radiofrequency catheter ablation has been proposed as a good therapeutic option, but the best criteria for determining the optimal site of ablation are still under debate.

Objectives: To report the clinical features, electrophysiologic characteristics, results of RFA[1], and long-term outcome in 18 patients with "Belhassen's VT” treated in our laboratory during the last 10 years, stressing the best electrophysiologic criteria for determining the optimal site of ablation.

Methods: Eighteen consecutive patients with this specific VT[2] underwent RFA in our laboratory during the last 10 years. RFA was acutely successful in 17 patients after one or two procedures (15 and 2 patients, respectively) using 4.1 ± 2.2 RF pulses. The putative ablation sites were defined by good pace-mapping (3 patients), earliest recorded Purkinje spike prior to the QRS onset during VT or sinus rhythm (6 patients), earliest endocardial activation during VT (1 patient), and diastolic potential preceding the Purkinje spike during VT and/or late diastolic potential in sinus rhythm (7 patients). In the patients with a definite successful ablation, the ratio of successful to unsuccessful radiofrequency pulse delivery to the diastolic potential site was compared to that of other methods. The ratio of successful RFA at the diastolic potential site (5:8) was higher than in the other methods (8:31), and the difference was statistically significant (P = 0.05). Successful ablation sites were more basal when the diastolic potential site was chosen.

Conclusion: The results of the present study confirm the high success rate and safety of RFA using conventional techniques in the management of “Belhassen VT,” suggesting that this procedure can be proposed as a first-line therapy. Ablating at a site demonstrating a late diastolic potential is at least as effective as ablating at a ventricular exit site, although the use of combined electrophysiologic criteria may be the optimal approach.

Background: Radiofrequency ablation has recently become a viable treatment option for unresectable primary or secondary lesions confined to the liver.

Objective: To study the local therapeutic efficacy, side effects and complications of radiofrequency ablation for the treatment of hepatocellular carcinoma and liver metastases This is the first reported experience of radiofrequency ablation for treating malignant hepatic tumors in Israel.

Methods: Fifteen consecutive patients, aged 53–73 years, with 23 lesions (8 patients with HCC[1] and 7 with secondary liver tumors) underwent radiofrequency ablation under general anesthesia. RITA nine-array 5 cm thermal ablation catheter and the model 1500 generator were used. The mean diameter of all tumors was 4.28 cm (range 1–10 cm). Three lesions were 1–3 cm in diameter (small), 17 lesions measured 3.1–5 cm (medium), and 3 measured 5.1–10 cm (large).

Results: Complete necrosis was found in 8 (66%) of 12 HCCs by computed tomography scan. Of the remainder, diffuse tumor recurrence was demonstrated in three lesions (25%) after lipiodol injection and there was one local tumor recurrence. In the metastases group complete necrosis was found in 5 of 11 lesions (45%). One major complication (peritonitis) was treated with antibiotics and four (26%) minor complications (right pleural effusion, small subcapsular hematoma) were monitored.

Conclusions: Radiofrequency ablation appears to be an effective, safe and relatively simple procedure for the treatment of liver tumors.

Background: Despite advances in cancer therapy the treatment of liver tumors remains a challenge. Most patients are poor candidates for surgical resection; both chemotherapy and irradiation have a low success rate and neither is without complications. New minimally invasive techniques for ablation of unresectable tumors have gained attention as effective treatment alternatives. Among these are percutaneous ethanol injection and radiofrequency ablation; both are effective for primary liver tumors and RFA is also effective for hepatic metastases.

Objective: To report our experience with PEI and RFA in the treatment of hepatic lesions.

Methods: The study included 49 lesions in 27 patients: 23 primary lesions in 13 patients treated with PEI and 26 lesions (22 secondary and 4 primary) in 14 patients treated with RFA. PEI was performed on an outpatient basis in the ultrasound suite; RFA was done in hospitalized patients (9 in the ultrasound suite and 4 in the operating room). Patients were followed with triphasic spiral computerized tomography 1 month after treatment and every 3±6 months thereafter.

Results: Complete necrosis was achieved with PEI on the first attempt in 11 of 23 primary lesions (91.3%). In 8.7% (2/23) a second series of treatments was required. Using RFA, complete necrosis was achieved in 85% of lesions (22/26) and partial necrosis in 15% (4/26). Complications included low fever (3 patients), high fever and abscess formation (1 patient), peri-tumoral necrosis (1 patient ) and portal vein thrombosis (1 patient ).

Conclusions: Our preliminary results confirm that PEI and RFA are an effective and safe option for treating hepatic tumors in patients unfit for surgery.
 

Background: Percutaneous transluminal septal ablation was recently introduced as an alternative to surgical treatment of hypertrophic obstructive cardiomyopathy. In this procedure, alcohol is injected into a proximal septal artery to create a localized myocardial infarction.

Objectives: To characterize the immediate and mediumterm results following PTSMA.

Methods: Of 13 patients referred for PTSMA, 8 were found suitable for the procedure. Hemodynamic parameters were evaluated prior to and following the procedure, and clinical and echo-Doppler parameters at 2 weeks and 9 months later.

Results: The procedure was technically successful in all patients. Resting left ventricular outflow gradient at rest (by Doppler) fell from 82 + 37 to 15 + 8 mmHg (P<0.001) 9 months later. Late post-procedural gradient after the Valsalva maneuver was 2 + 24 mmHg. The degree of mitral regurgitation fell from 2.0 + 0 to 1.5 + 0.5 (P<0.05). New York Heart Association class for dyspnea improved from 2.8 + 0.5 to 1.8 + (P<0.01) and Canadian Cardiovascular Society class for angina from 2.0 + 1.3 to 1.3 + 1.2 (P=0.08). Complete right bundle branch block developed in six patients, temporary complete atrioventricular block in three, and persistent block requiring permanent pacing in one. No flow in the distal left anterior descending coronary artery (presumably due to spilling of alcohol) was seen in one (with development of a small antero-apical infraction) and ventricular fibrillation 2 hours post-procedure in one. None of the patients died.

Conclusion: PTSMA provided a substantial reduction in left ventricular outflow gradient associated with an improvement in symptomatology. Serious complications are not uncommon. Long-term follow-up is unknown.
 

Background: Cryosurgery is a minimally invasive treat­ment option for prostate cancer.

Objectives: To report on the first series of cryosurgical ablation for prostate cancer performed in Israel.

Methods: Cryosurgical ablation of the prostate was undertaken in 2 patients aged 53-72 diagnosed with adenocarcinoma of the prostate. The procedures were performed percutaneously and were monitored by real-time trans-rectal ultrasound. The CRYOHIT machine applying Argon gas was used with standard or ultra-thin cryoprobes. The average follow-up was 12.8 months postsurgery (range 1- 24 months).

Results: No rectal or urethral injuries occurred and all patients were discharged from hospital within 24-48 hours. The duration of suprapubic drainage was 14 days in 10 patients and prolonged in 2. Early complications included penoscrotal edema in four patients, perineal hematoma in three, hemorrhoids in two and epidydimitis in one. Long-term complications included extensive prostatic sloughing in one patient and a perineal fistula in another, both of whom required prolonged suprapubic drainage. Minimal stress incontinence was noted in two patients for the first 8 weeks after surgery. None of the patients has yet regained spontaneous potency. A prostate-specific antigen nadir of less than 0.5 ng/ml was achieved in eight patients and an undetectable PSA level below 0.1 ng/ml in five patients.

Conclusion: Cryoablation for prostate cancer is safe and feasible, and the preliminary results are encouraging. Further study is needed to elucidate the efficacy of the procedure.

The future promises good news for the treatment of systemic lupus erythematosus, some of which can already be foreseen. Increased knowledge on genes that participate in the predis­position, pathogenesis, pharmacogenetics of, and protection against this disease may permit intervention at this level. Also, better understanding about the role of sex hormones has allowed trials of weak androgens or prolactin inhibitors. New immunomodulators or i mmunosuppresors may enable more precise treatment at the immunoregulatory level, and greater knowledge on the disturbance of circuits has already provided hints and even allowed trials of anti-interleukin-10 antibodies, an IL-10 decreasing agent, tolerance-induction strategies or intervention at the level of T cell co-stimulation, as well as immune ablation with subsequent stem cell transplantation. Autoantibodies can be removed, controlled by means of anti­idiotypes, which are blocked from reaching their target antigen or uncoupled from the tissues they have reached. All these treatment strategies will gradually become decanted in order to achieve the optimal treatment of SEE, which may turn out to be its cure.