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G Onik

Publications and source records attributed to G Onik.

14 recordsLinked to original sources

Cryosurgery re-visited for the removal and destruction of brain, spinal and orbital tumours.

Advances in neuroimaging and cryosurgical techniques have prompted us to re-evaluate the potential of cryosurgical techniques for the removal and the destruction of various neoplasms. We have used cryosurgical instrumentation to remove tumours in the brain, spine and orbit in 71 patients without complications. Cryosurgery was used to facilitate removal and extraction in 64 and to destroy residual neoplasms when removal was incomplete in 7. Intraoperative real time ultrasonic imaging permitted precise delimitation of tumours from surrounding tissues and allowed monitoring during the production of cryosurgical lesions thus permitting heretofore unavailable visualization of the production of cryogenic lesions in the central nervous system. New cryosurgical instrumentation was used to produce lesions up to three times larger than similar sized probes previously available. Our results reconfirm that cryosurgery facilitates the removal of tumours in the brain, spinal cord and orbit, reduces blood loss in vascular tumours, and is effective in ablating residual neoplasms involving the superior sagittal sinus, torcula and parasagittal areas. A Doppler flowmeter proved useful for monitoring sagittal sinus blood flow during the production of cryosurgical ablation of residual tumour attached to the walls of the sagittal sinus. Recent advances in ultrasonic and neuroimaging coupled with stereotactic techniques and improvements in cryosurgical instrumentation may prove useful in the future percutaneous destruction of selective intracranial neoplasms.

Adult

Cauda equina syndrome secondary to an improperly placed nucleotome probe.

Automated percutaneous lumbar discectomy has been shown to be a low morbidity procedure in the treatment of contained herniated lumbar discs. Described in this paper is a complication, i.e., a cauda equina syndrome secondary to a Nucleotome probe improperly placed in the thecal sac. The authors reemphasize the landmarks for the thecal sac, i.e., the medial border of the pedicles, and discuss the preventable nature of this type of complication.

Adult

Ultrasound-guided hepatic cryosurgery in the treatment of metastatic colon carcinoma. Preliminary results.

Cryosurgery, the in situ freezing of cancer, has been proposed in the past as a possible treatment for unresectable hepatic tumors. Its advantage lies in the fact that it is a very focal treatment sacrificing less normal tissue than surgical resection, allowing treatment of multiple lobes. Because cryosurgery does not affect large vessels, tumors in difficult locations, such as adjacent to the inferior vena cava (IVC), can be treated. With the use of intraoperative ultrasound to place the cryoprobes and monitor the freezing process, 18 patients with unresectable metastatic colon carcinoma confined to the liver were treated. Of the 18 patients treated, 4 (22%) are in complete remission as determined by computed tomography (CT) scans and carcinoembryonic antigen (CEA) levels, with a mean follow-up of 28.8 months. Four patients (22%) were not adequately treated at the time of cryosurgery. The number of lesions frozen in each patient ranged from 1 to 12, with a mean of 6 lesions. Fourteen patients had bilobar disease; three patients had previous right lobectomies with recurrences in their remaining left lobes prior to cryosurgery, and one patient had unilobar disease. Mean survival of the 14 cases with recurrence was 21.4 months, with 2 of the 14 still alive. Ultrasound-guided hepatic cryosurgery appears to be an effective treatment for metastatic colon carcinoma to the liver that is unresectable (including patients with bilobar and multiple lesions). These preliminary results indicate that the procedure warrants further study.

Adult

Percutaneous transperineal prostate cryosurgery using transrectal ultrasound guidance: animal model.

Cryosurgery has previously been used successfully to treat prostatic carcinoma. Inability to monitor the freezing led to local complications that limited the use of this modality. Recent studies have shown that monitoring of the freezing process can be accomplished using real-time ultrasound. In this study, transrectal ultrasound guidance was used to guide a cryoprobe percutaneously, using a transperineal approach, into the prostate. The extent of freezing was then monitored using ultrasound, taking care not to freeze the urethra or the rectum. Six dogs had the procedure without any complications. This study demonstrates the feasibility of a noninvasive treatment for prostatic carcinoma.

Animals

Automated percutaneous discectomy.

Automated percutaneous discectomy is a new, safe procedure for treating herniated lumbar discs still contained by the annulus or posterior longitudinal ligament. In 1985, one of the authors reported a percutaneous nucleus aspiration technique using a 2-mm aspiration probe. This small probe produced minimal tissue damage, allowing the procedure to be done on an outpatient. In this series, 518 patients were treated using this technique for an overall success rate of 85%. Compensation patients, elderly patients, and patients with previous surgery were treated successfully using percutaneous discectomy on an outpatient basis. No intraoperative or postoperative complications occurred.

Adult

Automated percutaneous lumbar diskectomy.

The use of automated percutaneous lumbar diskectomy for the treatment of herniated lumbar disks is increasing. More than 3000 physicians have been trained to perform the procedure, and over 40,000 cases have been completed worldwide. This review describes the development of automated percutaneous lumbar diskectomy, the selection of appropriate patients, how the technique is performed, and its efficacy relative to other methods of treatment.

Humans

Automated percutaneous lumbar diskectomy.

Automated percutaneous lumbar diskectomy was introduced in 1985. Development of this technique was instigated by the general trend in medicine toward less invasive procedures. Technique, indications, patient selection, and a review of the current literature are presented. Cumulative data indicate that the procedure has the least potential to do harm compared to open operations for treating lumbar disk herniations.

Humans

The process of freezing and the mechanism of damage during hepatic cryosurgery.

Experiments were performed to correlate the structures of liver tissue frozen during cryosurgery, liver frozen at various constant cooling rates, and unfrozen, dried normal liver. The results show that during freezing of tissue ice forms and propagates along the vascular system, expanding during freezing at low cooling rates. This expansion occurs over most of the region frozen during cryosurgery and may be one of the mechanisms of damage to tissue during cryosurgery.

Animals

Percutaneous automated biopsy in the diagnosis of primary infectious spondylitis.

Three cases of primary infectious spondylitis, two caused by Staphylococcus aureus and one by tuberculosis, were diagnosed using the method previously described for automated percutaneous discectomy. All three patients, in whom biopsy using fine needle techniques previously was unsuccessful, had positive cultures from specimens obtained using the automated method. The method combines the advantages of local anesthesia and minimal morbidity with the obtaining of adequate material for culture and pathological examination.

Adult

Automated percutaneous discectomy: a prospective multi-institutional study.

A prospective multi-institutional study was carried out to evaluate automated percutaneous discectomy in the treatment of lumbar disc herniations. Of the 327 patients who prospectively met the study criteria and were followed for longer than 1 year, 75.2% were successfully treated. When patients (n = 168) who prospectively did not meet the study criteria were treated, the success rate was 49.4%. One case of discitis was reported; otherwise, no other serious complications were noted, and specifically no vascular or nerve damage was encountered. This study indicates that automated percutaneous discectomy can be used successfully to treat lumbar disc herniations with minimal morbidity and emphasizes the need for proper patient selection.

Humans

Clinical experience with automated percutaneous lumbar discectomy.

Percutaneous automated aspiration discectomy is a new procedure for treating uncomplicated herniated lumbar discs. In a series of 200 patients, followed for up to six months, the overall success rate was 77.5%. Workers' compensation claimants, elderly patients, and patients with previous surgery can be treated successfully using percutaneous discectomy. Patients were treated on an outpatient basis. Patients returned to work significantly sooner after percutaneous discectomy than after microdiscectomy or laminectomy. No intraoperative or postoperative complications occurred.

Adult

Prospective comparison of preoperative imaging and intraoperative ultrasonography in the detection of liver tumors.

A prospective evaluation of the accuracy of preoperative computed tomography (CT), ultrasonography (US), and angiography was performed in 54 patients undergoing resection of hepatic neoplasms. The results were compared with surgical findings and intraoperative ultrasonography (IOUS). A total of 167 lesions was seen by means of IOUS, of which preoperative US enabled detection of 127 (76%). In 48 patients CT allowed detection of 91 of 150 lesions (61%), and in 35 patients angiography showed 56 of 107 lesions (52%). When the detection rate is analyzed according to hepatic segment, the greater overall accuracy of preoperative US may be attributed to a markedly better detection rate in lateral segment of the left lobe of the liver. Lesion size also represented a factor, with preoperative US allowing detection of a greater number of small (less than 2 cm) lesions compared with CT. In patients studied with both CT and US, the combined lesion-detection rate increased to 81% in the right lobe and 76% in the left lobe. Because of this we recommend that preoperative assessment include both CT and US evaluation of the liver. IOUS showed 25% to 35% additional lesions compared with preoperative US and CT. More importantly, 40% of the lesions demonstrated by IOUS were neither visible nor palpable at surgery. We recommend that IOUS be considered in all patients in whom resection of hepatic neoplasm is planned.

Angiography

Far-lateral disk herniation: treatment by automated percutaneous diskectomy.

Automated percutaneous diskectomy has certain advantages over other surgical approaches to the treatment of far-lateral disk herniation; primarily, the procedure can be performed under local anesthesia without soft-tissue disruption. We describe four patients with far-lateral herniations who were successfully treated with the procedure.

Adult