Percutaneous laser discectomy: experience and long term follow-up.

The classical microsurgical approach in the treatment of herniated nucleus pulposus (HNP) has been substituted over the years by endoscopical approach, in which it is possible to practice via endoscopy a laser thermo-discoplasty, and by percutaneous laser disc decompression and nucleotomy. Percutaneous laser disc decompression and nucleotomy have been performed worldwide in more than 40,000 cases of HNP. Because water is the major component of the intervertebral disc and in HNP pain is caused by disc protrusion pressing against the nerve root, a 980 nm Diode (Biolitec AG-Germany) laser introduced via a 21-G needle under X-ray or CT-scan guidance and local anesthesia, vaporizes a small amount of the nucleous pulposus shrinking the disc and relieving the pressure on the nerve root. A multicentric retrospective study with a mean follow-up of 6 years was performed on 900 patients suffering from relevant symptoms that had been therapy-resistant for 6 months on average before consulting our department. Evaluation included 585 (65%) males and 315 (35%) females. The average age of patients operated was 46 years (18-54). The success rate at a mean follow-up of 5 years (2-6 years) was about 70% with a very low complication rate.

Percutaneous surgical treatment in lumbar spinal stenosis with Aperius-PercLID: indications, surgical technique and results.

Interspinous spacers have recently been used in the treatment of lumbar spinal stenosis. In vitro studies have demonstrated a reduction in facet joint forces by 68% and annulus pressures by 63%. MRI studies have demonstrated increased canal and neural foraminal area after implantation of these devices. Previous studies by Zucherman et al. (Spine 30:1351-1358, 2005) demonstrated patient satisfaction rates of 71-73%.We carried out a multicentric retrospective study to assess the clinical outcomes following percutaneous posterior decompression using an interspinous spacer device (Aperius™-PercLID™ System; Kyphon-Medtronic). A total of 70 patients were included in the study. All of them had evidence of radiologically and clinically proven lumbar stenosis. The average age was 63.5 years. Patients completed the Zurich Claudication Questionnaire (ZCQ) and recorded pain levels on a Visual Analogue Scale (VAS). Average stay in hospital was 2 days. The average improvement in ZCQ included both symptomatic pain disappearance and functional ambulatory recovery. The average VAS pain score improved from 8.2 to 3.6 (scale of 1 to 10). The overall patient satisfaction rate was 76%. No complications were detected at 6 months' follow-up.

The role of provocative discography in minimally invasive selective endoscopic discectomy.

A discogenic etiology is being widely accepted as a primary source of chronic low-back pain. Even though increasing information is available on the pathophysiology of the degenerated disc, the present MR techniques are still not capable of pin-pointing the source of this pain. In other words, with a non-invasive MR1 study we can still not define which disc is painful and what are the characteristics of discogenic pain from an imaging perspective. Discography remains therefore the only functional test that can delimit both morphologically and by provocation which discs are involved in the patents clinical picture. In combination with endoscopic procedures it helps tailor treatments. We consider that this diagnostic tool should be used routinely and performed by the surgeon himself as part of a screening-therapy protocol in spine surgery. We present our considerations regarding this diagnostic-screening method based on our clinical and surgical experience in patients who have been evaluated and have undergone selective endoscopic disscetomy after the screening.

Utilidad de la discografía en la discectomía endoscópica selectiva mínimamente invasiva / The role of provocative discography in minimally invasive selective endoscopic discectomy

La etiología discogénica se está aceptando cada vez más como la fuente principal del dolor lumbar crónico. Aunque conocemos más y más los mecanismos patofisiológicos del disco intervertebral degenerado, las técnicas diagnósticas mediante RM aún no son capaces de delimitar la fuente de este dolor y cuales son sus características por lo menos en plan morfológico Neurocirugía 2002; 1: 27-31 (imagen). La discografía permanece por lo tanto el único test funcional que puede delimitar morfológicamente y mediante provocación qué disco(s) están involucrados en el cuadro clínico del paciente. En combinación con técnicas endoscópicas nos ayuda a delimitar y planificar los tratamientos.Consideramos que esta técnica diagnóstica debería ser utilizada de rutina y llevada a cabo por el mismo cirujano como parte de un protocolo de screening-terapia en cirugía espinal. Presentamos nuestras consideraciones con respecto a este metodo diagnostico-selectivo basándonos en nuestra experiencia clínica y quirúrgica en pacientes que han sido evaluados y en los cuales se ha llevado a cabo una discectomía endoscópica selectiva (AU)

Involvement of spinal nerves in neurofibromatosis.

Spinal tumors are a frequent form of manifestation of neurofibromatosis. Out of 171 patients, who have been operated on over a ten years period on spinal tumors, 7 patients had neurofibromatosis (4.1%). A total of 9 operations were performed, removing 20 spinal tumors. Three patients had multiple neurofibromas. Half of the neurofibromas had a dumbbell configuration with a larger extraspinal extension. In three patients a family history of neurofibromatosis and typical dermatological signs were evident. Two cases will be selected and the basic concept regarding treatment and the risks involved will be discussed.

The lounging position for posterior fossa surgery: anesthesiological considerations regarding air embolism.

The sitting position for operations in the posterior fossa remains controversial in both adults and children, primarily because of the risk of air embolism. The reports on the incidence of this complication are varied. We retrospectively reviewed the data on 704 patients (age range 1-82 years) operated on in a lounging position for varied posterior fossa pathology from January 1984 up to December 1989. As diagnostic monitoring, we uniformly employed a Doppler ultrasound device, an atrial catheter, and capnometry. In 37 adults (5.5%) and 9 children (9/34) air embolism was diagnosed, without either morbidity or mortality. A lounging position, together with adequate infusion therapy and ventilation with PEEP, considerably reduces the risk of air embolism.

Surgery of petroclival meningiomas: report of 24 cases.

Twenty-four patients with petroclival meningiomas were operated upon at the neurosurgical clinic of the City Hospital of Hannover between 1978 and 1987. Seventeen were women and seven men; the mean age was 45 years. Symptoms were usually present for more than 2 years before the diagnosis was made. The most common symptom was disturbance of gait; the most common preoperative sign was cranial nerve deficit, mainly of the 7th and 8th nerves. Preoperative neuroradiological evaluation included computed tomography and four-vessel cerebral angiography. Fifteen patients (62%) had a tumor larger than 2.5 cm in its major diameter. The surgical approaches used were the retromastoid, pterional, subtemporal, and combined retromastoid-subtemporal. We developed a modification of the retromastoid-subtemporal approach with preservation of the transverse sinus and used this in the last 2 patients. There was no postoperative death; 11 patients (46%) suffered postoperative complications, mainly in the form of cranial nerve deficits, often reversible. "Total" tumor removal was achieved in 17 patients (71%). Twenty patients (83%) were independent at the time of discharge from the hospital. With accurate neuroradiological evaluation, careful choice of the surgical approach, and sound application of microsurgical techniques, petroclival meningiomas may be "totally" and safely resected in a significant number of patients.

Revascularization of nerve grafts: an experimental study.

The time course of revascularization of grafted nerves, and the possible dependence of this revascularization on the length of the graft are two related questions that are addressed. Survival of Schwann cells in the nerve graft and a timely revascularization must be seen as a precondition for an optimal regeneration process. The revascularization process after different postoperative intervals is demonstrated in the sciatic nerve of rabbits by the use of microangiography, with Roentgen-positive water-soluble contrast medium. The third postoperative day is the earliest point in time for revascularization of the autologous graft from surrounding tissues. On the fourth postoperative day, a hyperemia with extension to all sides of the intraneural vessel system exists that still persists on the fifth and sixth days. In one experimental group, revascularization was allowed to occur only in a longitudinal direction. Revascularization under these conditions proved to be poor, slow, and obviously dependent on the length of the graft. Survival and subsequent function of free autologous nerve grafts may depend on the diameter of the grafts and the quality of the recipient site, but not on the length of the grafts, when timely revascularization from the surrounding tissues is present.