Direct intrahepatic portacaval shunt: an experimental study.
(17/1062)
AIM: To determine the feasibility of creating direct intrahepatic portacaval shunt (DIPS) in swine with puncture under sonographic guidance. METHODS: DIPS was created in 10 domestic swine under sonographic guidance. Liver function, blood ammonia level and portosystemic gradient (PSG) were compared before and after the procedure. Patency of shunt was followed by portography every 7 days after DIPS. RESULTS: DIPS was successfully established in all 10 swine without any complications. One day after procedure the alanine aminotransferase (ALT), aspartate aminotransferase (AST), and blood ammonia level (BAL) of swine rose from 5.40+/-0.69, 16.00+/-0.79 and 35.66+/-4.10 to 34.20+/-3.46, 59.70+/-2.22 and 66.94+/-3.44 respectively. (P<0.05). The PSG decreased from 0.59+/-0.20 kPa to 0.24+/-0.11 kPa after DIPS (P<0.05). The shunt of 10 swine was kept patent from 7-28 days (median patency time was 14 days). CONCLUSION: This initial experience demonstrated that creating intrahepatic portacaval shunt from retrohepatic segment of IVC to portal vein with puncture under sonographic guidance in swine is safe and feasible. Further studies are necessary to perform DIPS in cirrhosis patients. (+info)
Slow pathway catheter ablation of atrioventricular nodal re-entrant tachycardia guided by electroanatomical mapping: a randomized comparison to the conventional approach.
(18/1062)
BACKGROUND: Electroanatomical mapping may be expected to improve safety, efficiency and efficacy of selective slow pathway ablation for atrioventricular nodal re-entrant tachycardia (AVNRT). The goal of this prospective randomized study was to compare the efficiency of conventional fluoroscopic and electroanatomical mapping in guiding catheter ablation of AVNRT. METHODS AND RESULTS: Following induction of typical AVNRT, 20 consecutive patients were randomized to either conventional fluoroscopic or electroanatomical (CARTO) mapping to guide slow pathway ablation using a 4mm electrode. Endpoints for ablation were non-inducibility and no more than a single AV nodal echo on aggressive retesting. Acute procedural success was 100% in both groups, with no complications. Although there were no differences in time taken for pre- and post-ablation electrophysiological evaluations, in the electroanatomical group the ablation portion of the procedure showed a substantial reduction in duration (12.6+/-6.8 vs 35.9+/-18.3 min; P< 0.001) and fluoroscopic exposure (0.7+/-0.5 vs 9.6+/-5.0 min; P< 0.001) compared with the fluoroscopic group, reflected in reduced total procedure time (83.6+/-23.6 vs 114+/-19.3 min; P=0.008) and total fluoroscopic exposure (4.2+/-1.4 vs 15.9+/-6.4 min; P< 0.001). Electroanatomical mapping was associated with a lower number (2.7+/-1.6 vs 5+/-2.8; P=0.018), duration (165.3+/-181.6 vs 341+/-177.7s; P=0.013), and total energy delivery (24.3+/-3.1 vs 28.7+/-4.5 watts; P=0.042) of RF applications. There were no acute or long-term (8.9+/-2.2 month) complications or arrhythmia recurrence in either group. CONCLUSIONS: While both conventional and non-fluoroscopic electroanatomical mapping are associated with excellent results in guiding ablation of typical AVNRT, the latter offers significantly shorter procedure and fluoroscopy times, improving the efficiency of the procedure and reducing X-ray exposure. (+info)
Image-guided and intensity-modulated radiosurgery for patients with spinal metastasis.
(19/1062)
BACKGROUND: Radiosurgery can deliver a single, large radiation dose to a localized tumor using a stereotactic approach and hence, requires accurate and precise delivery of radiation to the target. Of the extracranial organ targets, the spine is considered a suitable site for radiosurgery, because there is minimal or no breathing-related organ movement. The authors studied spinal radiosurgery in patients with spinal metastases to determine its accuracy and precision. METHODS: The spinal radiosurgery program was based on an image-guided and intensity-modulated, shaped-beam radiosurgical unit. It is equipped with micromultileaf collimators for beam shaping and radiation intensity modulation and with a noninvasive, frameless positioning device that uses infrared, passive marker technology together with corroborative image fusion of the digitally reconstructed image from computed tomography (CT) simulation and orthogonal X-ray imagery at the treatment position. These images were compared with the port films that were taken at the time of treatment to determine the accuracy of the isocenter position. Clinical feasibility was tested in 10 patients who had spinal metastasis with or without spinal cord compression. The patients were treated with fractionated external beam radiotherapy followed by single-dose radiosurgery as a boost (6-8 grays) to the most involved portion of the spine or to the site of spinal cord compression. RESULTS: The accuracy for the isocenter was within 1.36 mm +/- 0.11 mm, as measured by image fusion of the digitally reconstructed image from CT simulation and the port film. Clinically, the majority of patients had prompt pain relief within 2-4 weeks of treatment. Complete and partial recovery of motor function also was achieved in patients with spinal cord compression. The radiation dose to the spinal cord was minimal. The maximum dose of radiation to the anterior edge of the spinal cord within a transverse section, on average, was 50% of the prescribed dose. There was no acute radiation toxicity detected clinically during the mean follow-up of 6 months. CONCLUSIONS: Image-guided, shaped-beam spinal radiosurgery is accurate and precise. Rapid clinical improvement of pain and neurologic function also may be achieved. The results indicate the potential of spinal radiosurgery in the treatment of patients with spinal metastasis, especially those with solitary sites of spine involvement, to increase the prospects of long-term palliation. (+info)
Intraventricular monitoring for temporal lobe epilepsy: report on technique and initial results in eight patients.
(20/1062)
OBJECTIVE AND IMPORTANCE: Resective surgery is an effective treatment for refractory temporal lobe epilepsy. In difficult cases, invasive monitoring may be needed to precisely lateralise and localise seizure foci of mesial temporal origin. The authors present a modified technique for image guided, endoscopic placement of an intraventricular electrode array (IVE) that abuts the amygdalo-hippocampal complex. METHODS: Eight patients with suspected mesial temporal lobe epilepsy had placement of an IVE in conjunction with other invasive electrodes. Seven of these patients also had subdural grid or strip electrodes and four had foramen ovale electrodes. Frameless image guidance was used to place a custom 10-contact depth electrode through a rigid neuroendoscope within the atrium of the lateral ventricle. Once proper orientation towards the temporal horn was confirmed, the IVE array was advanced into the temporal horn to the temporal tip. The endoscope was removed and electrode placement was confirmed through an intraoperative lateral skull radiograph and on visual inspection at the time of resection in two cases. RESULTS: The IVE was crucial for localisation in one patient and helped localisation in four others. Surgery was offered to seven patients. The only serious complication of IVE placement was a thalamic contusion presumably from an errant electrode tip. One electrode was inadvertently placed into the frontal horn. There were no deaths and no permanent morbidity associated with the procedure. CONCLUSION: Endoscopically placed temporal horn, intraventricular electrodes provide an alternative to transcortical depth electrode placement. The technique hopefully can avoid complications associated with multiple depth electrode placements, especially when bilateral amygdalo-hippocampal electrical recordings are desired, although there may be a steep learning curve. (+info)
Telerobotic laparoscopic repair of incisional ventral hernias using intraperitoneal prosthetic mesh.
(21/1062)
Laparoscopic ventral hernia repair shortens the length of hospital stay and achieves low rates of hernia recurrence. The inherent difficulties of performing advanced laparoscopy operations, however, have limited the adoption of this technique by many surgeons. We hypothesized that the virtual operative field and hand-like instruments of a telerobotic surgical system could overcome these limitations. We present herein the first 2 reported cases of telerobotic laparoscopic ventral hernia repair with mesh. The operations were accomplished with the da Vinci telerobotic surgical system. The hernia defects were repaired with dual-sided, expanded polytetrafluoroethylene (ePTFE) mesh. The mesh was secured in place with 8 sutures that were passed through the abdominal wall, and 5-mm surgical tacks were placed around the circumference of the mesh. The 2 operations were accomplished with total operative times of 120 and 135 minutes and total operating room times of 166 and 180 minutes, respectively. The patients were discharged home on postoperative days 1 and 4. The surgeon sat in an ergonomically comfortable position at a computer console that was remote from the patient. Immersion of the surgeon within the 3-dimensional virtual operative field expedited each stage of these procedures. The articulation of the wristed telerobotic instruments greatly facilitated reaching the anterior abdominal cavity near the abdominal wall. This report indicates that telerobotic laparoscopic ventral hernia repair is feasible and suggests that telepresence technology facilitates this procedure. (+info)
Long-term prognosis of parathyroid function for chronic dialysis patients after minimally invasive radioguided parathyroidectomy (MIRP).
(22/1062)
BACKGROUND: Minimally invasive radioguided parathyroidectomy (MIRP) for primary hyperparathyroidism for one gland, located by scanning with technetium 99m-labelled sestamibi (MIBI), has been performed. Total parathyroidectomy with autotransplantation or percutaneous ethanol injection therapy (PEIT) for severe secondary hyperparathyroidism (2HPT) has also been performed. METHODS: The present study examined the possibility of maintaining parathyroid function within a target range [intact parathyroid hormone (i-PTH) +info)
Combined radioguided parathyroidectomy and intravenous vitamin D therapy for the treatment of uraemic hyperparathyroidism.
(23/1062)
Therapy combining radioguided parathyroidectomy (PTx) followed by intravenous maxacalcitol was given to a 50-year-old Japanese man referred for treatment of uraemic secondary hyperparathyroidism. After laboratory and radiological examinations, the patient underwent uncomplicated, successful surgery, but glands that had not been detected radiologically before the procedure became apparent with a scintillation counter immediately after the removal of the swollen gland. To prevent relapse of secondary hyperparathyroidism in the remaining glands, 10 microg of maxacalcitol was injected intravenously after each dialysis session. Following a minimally invasive radioisotope-guided PTx, the potential risk of relapse in the remaining glands has to be considered and intensive medical therapy should be instituted immediately after the operation. Further study needs to elucidate whether this treatment strategy can improve the long-term prognosis of patients with secondary hyperparathyroidism (+info)
Incremental diagnostic value of preoperative 99mTc-MIBI SPECT in patients with a parathyroid adenoma.
(24/1062)
The purpose of this prospective study was to evaluate the diagnostic value of early parathyroid SPECT combined with quantitative analysis as compared with planar imaging in patients undergoing minimally invasive radioguided surgery. METHODS: A total of 52 consecutive patients with primary hyperparathyroidism underwent planar and SPECT parathyroid scintigraphy 2-5 d before surgery. Each patient had a single-tracer dual-phase technique using (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) and a double-tracer subtraction technique using a delayed (99m)Tc-pertechnetate scan. Immediately after the first (99m)Tc-MIBI planar image, a SPECT study was acquired. Before radioguided parathyroidectomy, each patient was reinjected with (99m)Tc-MIBI. Serum calcium levels were available for all patents before surgery and at 8 and 24 h after surgery. Serum parathyroid hormone (PTH) levels were also available for all patients. Quantitative analysis was performed using the average count ratio of parathyroid to left thyroid lobe, right thyroid lobe, and maximum thyroid activity. All patients had histopathologic examination of the removed glands. RESULTS: The average time for radioguided surgery was 30 min (range, 20-40 min). Postsurgical calcium levels correlated significantly with the adenoma weight (r = 0.5; P = 0.016). Combined planar scintigraphy correctly identified 41 adenomas (79%). SPECT increased the sensitivity to 96%. SPECT was superior to planar imaging in 9 patients, mainly in patients with ectopic adenomas or with multinodular goiters. Gland size did not affect significantly the detectability of SPECT. (99m)Tc-MIBI retention was noted in only 31 adenomas (60%). The average uptake ratios of parathyroid counts to the left lobe, right lobe, and maximum thyroid activity were 1.20 +/- 0.42, 1.29 +/- 0.45, and 0.84 +/- 0.35, respectively. The latter ratio was significantly correlated with PTH levels before surgery (r = 0.408; P = 0.04). CONCLUSION: Our data indicate that early preoperative SPECT in patients with primary hyperparathyroidism is essential for accurate localization of parathyroid adenomas and for the selection of patients who are candidates for minimally invasive radioguided surgery. Planar parathyroid imaging is less sensitive compared with SPECT, and washout kinetics of (99m)Tc-MIBI are unreliable in the dual-phase technique. Patients with higher presurgical PTH levels may especially benefit from radioguided surgery. (+info)