Irreversible electroporation: Beyond the limits of tumor ablation

Irreversible Electroporation (IRE) is a non-thermal tumor ablation technique. High-voltage electrical pulses are applied between pairs of electrodes inserted around and/or inside a tumor. The generated electric current induces the creation of nanopores in the cell membrane, triggering apoptosis. As a result, IRE can be safely used in areas near delicate vascular structures where other thermal ablation methods are contraindicated. Currently, IRE has demonstrated to be a successful ablation technique for pancreatic, renal, and liver tumors and is widely used as a focal therapeutic option for prostate cancer. The need for specific anesthetic management and accurate parallel placement of multiple electrodes entails a high level of complexity and great expertise from the interventional team is required. Nevertheless, IRE is a very promising technique with a remarkable systemic immunological capability and may impact on distant metastases (abscopal effect).

[Life-threatening hemoptysis. Treatment with transcatheter embolization]

OBJECTIVE

To evaluate the immediate and long-term efficacy of transcatheter embolization of bronchial, systemic and pulmonary arteries to treat life-threatening hemoptysis. Likewise, we propose the systematic treatment of life-threatening hemoptysis by means of transcatheter embolization.

MATERIAL AND METHODS

One hundred seven angiographies were performed on the same number of patients experiencing life-threatening hemoptysis with bleeding exceeding 150 ml in 24 hours. Before angiography, we rinsed the vessels with cold saline solution and adrenalin through the catheter. Thirty-three patients were female and 74 were male. Mean age was 52.3 years (range 12 to 75 years). Embolization was performed in 104 (3 in patients with recurrent hemoptysis) using polyvinyl alcohol and micro-coils. Bronchial and systemic arteries of the affected hemithorax (mammary and lateral thoracic arteries) were checked in all patients. If findings were negative or bleeding was recurrent, we also performed pulmonary arteriography.

RESULTS

In two cases we were unable to catheterize the artery theoretically responsible for bleeding. Examination of both arterial and systemic vessels proved normal in one patient. The embolization technique was successful in 99% (103/104) of the cases and the rate of immediate clinical success was 95.1% (99/104). The mean time of follow-up was 43.2 months (range 3 to 66 months). Hemoptysis recurred in 15.3% (16 cases) within a mean 8.3 months (range 15 days to 48 months); embolization was repeated in 14 of these patients with satisfactory results, while two underwent surgery. In five patients (4.8%) we observed complications requiring no additional medical treatment: one instance of coil migration to the deep femoral artery, from which the coil was removed in a basket; two cases of bronchial artery extravasation with small mediastinal hematomas; and two hematomas at the points of puncture.

CONCLUSION

Selective or supra-selective embolization of the arteries that feed the bronchi provides effective management of life-threatening hemoptysis. No additional medical treatment is usually required.

Doppler-duplex ultrasound in renal colic

OBJECTIVE

To determine the role of intrarenal Doppler ultrasound (US) in patients with renal colic and to establish the usefulness of this diagnostic method.

MATERIALS AND METHODS

In 121 patients with renal colic and 70 healthy individuals, 382 kidneys were examined with color duplex US. Mean intrarenal-arterial resistive index (RI), and the difference of mean RIs (dRI) between both kidneys were determined. In 64 patients, RI and dRI were compared with urographic findings (time of delay pyelogram between both kidneys).

RESULTS

In the 70 healthy individuals, RI was 0.62 +/- 0.045 and dRI 0.018 +/- 0.01. In the 121 patients with renal colic, RI (0.71 +/- 0.06) was significantly superior (P < 0.001) with respect to the opposite kidney, with a dRI of 0.09 +/- 0.055. In a correlation performed in 64 patients with urographic findings among color doppler US, with a RI > or = 0.70 and/or dRI > or = 0.06 as an indicative value of obstruction, sensitivity and specificity were 91.8% for patients with delayed pyelogram (n = 37 patients), and 48.1% for patients with nondelayed pyelogram (n = 27 patients) with a specificity of 92.8% with respect to the group of normal patients. In the group of patients with delayed pyelogram, RI was significantly superior (P < 0.05) in patients with an evolution time greater than 24 hours, in patients with proximal ureteral obstruction and in patients who had signs of pyelonephritis. There were no significant differences in the group of patients with nondelayed pyelograms.

CONCLUSION

Color Doppler US is useful to fundamentally evaluate the consequences of the obstruction on renal function. Other factors such as evolution time of the symptomology, obstruction level, or existence of pyelonephritis can alter the US-Doppler values.

[The clinical efficacy and complications of the transjugular intrahepatic portosystemic shunt-stent]

TIPSS is a new therapeutic modality for decompressing the portal tree and its use has broadened in the last five years. From February 1993 to August 1994 a prospective study was performed to evaluate its efficacy and safety. Nineteen cirrhotic patients (Child A-5, B-10, and C-4) with a TIPSS placed were included. The mean follow-up was 7.2 months. The indication was therapy of esophageal variceal bleeding in 18 patients (acutely in 8 and elective in 10 patients) and refractory ascites in one. In all cases could the "stent" be placed and the portocaval gradient decreased from 22.8 +/- 3.71 to 9.3 +/- 2.27 mmHg. In the first thirty days the mortality rate was 10.5%, with the following complications: two portal thromboses, two acute non-lithiasic cholecystitis, one hemoperitoneum, one spontaneous bacterial peritonitis, and one hepatic encephalopathy. During the follow-up period two patients developed hemorrhagic relapses and two additional patients subclinical encephalopathy. TIPSS dysfunction was observed in 57.8%.

Transthoracic aspiration biopsy of pulmonary and mediastinal lesions

Thoracic aspiration biopsy (TAB) constitutes a useful technique in establishing a diagnosis in diseases of the lungs and mediastinum. Results obtained from 1046 fluoroscopically-guided TABs are presented with review of the most important aspects of the technique. Diagnostic accuracy in malignancy detection was 93.8% in lung lesions (n = 984) and 74.5% in mediastinal lesions (n = 62). Sensitivity was higher in peripheral than in central lesions (96% vs. 87%, respectively). Specificity was 100% in both groups. Sensitivity in lesions smaller than 2 cm was 70% and 94% in larger lesions. Aspiration biopsies performed with Chiba and Franseen needles showed a similar sensitivity (95%) higher than with other types of needles. A pneumothorax developed in 138 patients (13.2%). Only eight of these required the use of an endothoracic tube (0.8% of all biopsies).