The Histopathological Effects of the CO2 Versus the KTP Laser on the Brain and Spinal Cord: A Canine Model

First experiences with a 2.0-μm near infrared laser system for neuroendoscopy

Nd:YAG, argon and diode lasers have been used in neurosurgical procedures including neuroendoscopy. However, many neurosurgeons are reluctant to use these lasers because of their inappropriate wavelength and uncontrollable tissue interaction, which has the potential to cause serious complications. Recently, a 2.0-microm near infrared laser with adequate wavelength and minimal tissue penetration became available. This laser was developed for endoscopic neurosurgical procedures. It is the aim of the study to report the initial experiences with this laser in neuroendoscopic procedures. We have performed 43 laser-assisted neuroendoscopic procedures [multicompartmental congenital, posthaemorrhagic or postinfectious hydrocephalus (n = 17), tumour biopsies (n = 6), rescue of fixed and allocated ventricular catheters (n = 2), endoscopic third ventriculostomy (ETV, n = 17) and aqueductoplasty (n = 1)] in 41 patients aged between 3 months and 80 years. The laser beam was delivered through a 365-microm bare silica fibre introduced through the working channel of a rigid endoscope. It was used for the opening of cysts, perforating the third ventricular floor, and for coagulation prior to and after biopsy. The therapeutic goals [creating unhindered cerebrospinal fluid (CSF) flow between cysts, ventricles and cisterns, sufficient tissue samples for histopathological diagnosis and catheter rescue] were achieved in 40 patients by the first and in 2 patients by a second neuroendoscopic operation. In one child, a CSF shunt was later required despite patency of the created stoma proven by magnetic resonance imaging (MRI). In another patient ETV was abandoned due to a tiny third ventricle. There was neither mortality nor transient or permanent morbidity. The authors conclude that the use of the 2.0-microm near infrared laser enables safe and effective procedures in neuroendoscopy.

Cervical percutaneous laser disc decompression: preliminary results of an ongoing prospective outcome study

OBJECTIVE

This study identifies the efficacy of laser disc ablation and compares the relative efficacy of Holmium2100; YAG and KTP532 laser wavelengths in the treatment of broad-based cervical disc protrusions presenting with cervical axial pain with compressive or noncompressive radicular symptoms.

BACKGROUND

A preliminary report on a prospective outcome study of cervical laser disc ablation and decompression in the management of cervical disc prolapse and discographically confirmed discogenic pain in association with radicular pain.

METHODS

Patients with chronic cervical pain and radicular symptoms unresponsive to conservative treatment were assessed with magnetic resonance (MR) scans. Those with broad-based disc bulge or discal degeneration were assessed with provocative discography to isolate the source of pain. Percutaneous laser disc decompression was performed as a day case procedure on 105 patients at 108 levels under X-ray control via the anterior approach with side-firing probes in patients.

RESULTS

At a minimum follow up of 24 months, 51% of patients demonstrated a sustained significant clinical benefit with an additional 25% in whom functional improvement was noted. No difference in outcome was identified either with the wavelengths used or with laser annealing or painful discal tears. The cohort integrity of the study was 80%.

CONCLUSION

The sustained nature of the benefit (mean 3.5 years at final follow up) after long-term preoperative symptoms (mean 3.9 years) in 76% patients rules out placebo effect. Benefits occurred independently of the wavelength of laser used.