Chair of Neurosurgery Medicomilitary Academy, Saint Petersburg, Russia
Neurologic manifestations of discogenic compression at a lumbar level are the most spread pathology among human chronic diseases. Unsatisfactory results of surgical interventions and a considerable number of relapses, watched in treatment of hernias of lumbar intervertebral discs, can be explained by use of standard and uniform methods in a rather heterogeneous group of patients without taking into account a phase of a clinical course of discogenic compression, data of profound preoperative visualization, intraoperative estimation of relationships between a compressing substrate and neurovascular structures, as well as pathomorphologic peculiarities of vertebral and (or) root canals.
Full-value radiation diagnosis of all constituents of discogenic compression and taking into consideration a phase of a clinical course are a pledge of successful preoperative planning, which ensures a correct choice of an approach. Precise intraoperative verification of versions of topographic-anatomic relationships between a compressing substrate and neurovascular structures, carried out during discectomy, condition a volume and content of surgical manipulations, totality and quality of discectomy and efficacy of intervention.
There were 489 cases with primary discogenic pain syndromes, operated in the Clinic of Neurosurgery of the Medicomilitary Academy during 1997-2002. Endovideomonitoring was used in 68 cases (13.9%). Interventions were performed without it in 421 patients (86.1%). The majority of patients were in their active age (94.5%). Relapses of the disease, demanding reoperatoin, were present in 11.2% of cases, included into the present study.
Differentiated choice of microsurgical approaches was dependent on a phase of a clinical course of discogenic compression, results of preoperative visualization and anatomic peculiarities of a vertebral canal.
In case of clinical compensation or subcompensation and absence of stenosis of vertebral and/or root canals, primary interventions for decompression of neurovascular structures were performed with use of interlaminar or widened interlaminar approaches. Operation for radicular-ischemic complications of discogenic compression, made in a phase of moderate clinical decompensation and at one level, were characterized by applying a widened interlaminar approach. Hemilaminectomy was a method of choice in bilateral compression and stenosis. Hemilaminectomy or laminectomy were made in a phase of gross clinical decompensation.
Use of endovideomonitoring allowed to give up unjustified widening of an approach at the initial stage of intervention in 33.9% of cases, to avoid intraoperative damage of epidural veins and radicular and radiculomedullar arteries in 60.7% and 13.6% of patients respectively, to reveal and remove residual sequesters from an intervertebral space in 31.8% of cases. Besides, residual sequesters, which had migrated into a subligamentous space, were detected and removed in 9.1% of patients during interventions. In our opinion, these circumstances led to reduction of a number of complications and relapses.
The clinical study showed, that first of all intraoperative monitoring allows to estimate an approach adequacy, as well as topographic-anatomic relationships between hernia of an intervertebral disc, a dural sac, the spinal cord roots and vessels before and after discectomy; secondly, it helps to choose an adequate approach and reduces a risk of iatrogenic damage of neurovascular structures; thirdly, it permits to visualize laminas of vertebral arches of adjacent vertebrae, quality and completeness of curettage, presence of residual sequesters in an intervertebral, subligamentous and dural spaces, as well as to evaluate efficacy of hemostasis in an intervertebral space during nucleoscopy.
Differentiated choice of a microsurgical approach allowed to reduce a number of relapses in a group of patients, operated without endovideomonitoring and with it up to 6.9% and 2.9% (p<0.05) respectively.