Vascular and neural pathology of lumbosacral spinal stenosis

During a study of the intrinsic vasculature of the lumbosacral spinal nerve roots in cadavers, a typical case of spinal stenosis was encountered. A review of the antemortem anamnesis revealed that this patient had had an intermittent claudication of the cauda equina. Investigation of the concomitant vascular and histopathological alterations of the affected nerve roots suggested that the claudication may have resulted from ectopic nerve impulse discharges elicited by rapid changes in the blood supply following exertion. The unexpectedly slight apparent neural deficit relative to observed root damage may be attributed to a neuronal plasticity within the spinal cord that permitted functional compensations to develop during the slow acquisition of the chronic nerve root pathology.     

Lumbar spinal stenosis: surgical considerations

Spinal stenosis is an acquired or congenital narrowing of the spinal or nerve-root canals. Surgical treatment is often effective. Acquired spinal stenosis most commonly occurs in those with degenerative disk disease and arthritic facets. If the degenerative process stabilizes and there is adequate room to accommodate the neural contents, symptomatic patients become asymptomatic. Residual stability after decompression must be assessed in patients having multilevel decompression. Fusion maybe indicated. In women with osteoporosis coexisting with degenerative scoliosis and spinal stenosis, decompression for concave nerve-root compression and fusion are necessary. Spinal fusion is not indicated in patients with lumbar spinal stenosis having unilateral decompression for lateral stenosis. Patients with central-mixed stenosis may not need fusion. Patients with spinal stenosis after laminectomies and diskectomies had better results when arthrodesis was done in conjunction with repeated decompression. Arthrodesis with instrumentation and decompression is recommended for patients with degenerative spondylolisthesis.     

Extension to the sacrum of previous adolescent scoliosis fusions in adult life.

Numerous reports have indicated an increased risk for the development of precocious degenerative changes leading to pain in patients who had fusions done in adolescence for scoliosis, which extended into the lower lumbar spine. The anatomic situation may lead to instability, or spinal stenosis or both. This paper represents the evolving experience in reconstructive surgery for patients in whom a fusion was to be extended to the sacrum. Reconstructive surgery will require, if necessary, decompression posteriorly for spinal stenosis if present. Stabilization is acquired through an anterior and posterior approach with anterior and posterior instrumentation. The evolution of treatment modalities since 1976 shows a decreased pseudarthrosis rate from an initial 83% to 3% at present.     

Somatosensory evoked potentials as an aid in the diagnosis and intraoperative management of spinal stenosis

The use of somatosensory evoked potentials (SEPs) in localizing the level, extent, and laterality of nerve root entrapment is clinically important. In patients with lumbar spinal stenosis, this is especially true. This study defines a prospective investigation of 20 patients with preoperative SEPs of which 11 patients had intraoperative SEPs correlated with their computed tomographic (CT) scan and/or myelographic findings. The results confirm a high incidence of 4th and 5th lumbar and 1st sacral nerve root involvement. The posterior tibial nerve was abnormal in 95%, the peroneal in 90%, and the sural in 60% in the symptomatical lower extremity. Upper lumbar segments were barely affected as evident by the low incidence of saphenous nerve abnormality in only 12% of the patients. The posterior tibial nerve had the highest yield and was useful for screening. Bilateral lower extremity abnormalities were found in seven of 20 cases studied with two patients having bilateral symptoms and findings. Therefore, bilateral lower extremity SEP evaluation can reveal previously unsuspected pathology and is strongly recommended in preoperative evaluations. SEPs can serve as a useful intraoperative tool to guide the surgeon during a decompressive surgical procedure. SEPs are specifically helpful in spinal stenosis with a paucity of clinical findings and equivocal CT scan or myelographic studies. SEPs seem much more sensitive and effective than conventional electrodiagnostic tests in detecting spinal nerve root compression secondary to spinal stenosis.     

痛风性腰椎管狭窄症的诊治体会

目的探讨痛风病变所致腰椎管狭窄症的诊断及治疗方法。方法对7例经保守治疗无效、术中及病理证实为痛风性椎管狭窄症的患者行后路椎板开窗减压、椎管神经根管扩大及神经根松解、椎弓根固定椎间植骨融合术。对患者临床表现、手术前后血尿酸水平、影像学特征及手术预后进行分析。结果 7例患者术前均存在不同程度的腰腿痛及神经根性间隙性跛行,伴或不伴全身其他部位痛风病变及疼痛,血尿酸高低不一,CT检查可见关节突增生破坏,伴或不伴黄韧带钙化,椎管骨性狭窄。术中见关节突关节囊及黄韧带尿酸盐结晶沉着,关节突增生及骨质破坏,椎管显著狭窄。患者均获得随访,时间6~55个月。随访期间患者腰腿痛均消失,Barthel指数及VAS评分较术前显著好转,差异有统计学意义(P0.05);血尿酸无显著变化,术后无复发及并发症发生。结论痛风性腰椎管狭窄症的诊断主要是临床表现与影像学结果相结合,对保守治疗无效的患者手术治疗效果良好。     

Redundant nerve roots in patients with degenerative lumbar spinal stenosis

Extensive fundamental and clinical investigations have been performed concerning redundant nerve roots (RNR) and the pathogenesis of cauda equina claudication (CEC) in degenerative lumbar canal stenosis (DLCS). These investigations consisted of (1) anatomic observations on RNR in 117 fixed cadaveric specimens, (2) myelographic study in 117 patients with or without DLCS, (3) operative observation on neural elements with special reference to the cauda equina in 56 DLCS patients (including a postoperative follow-up), and (4) electrophysiologic tests using spinal cord action potential recording under walking load preoperatively and intraoperative measurement of nerve conduction velocity of RNR. The RNR have neuronal losses resulting from a longer duration stenosis that suggests a sort of friction neuritis. Complicated factors contribute to the pathogenesis of CEC and the development of root gripping, such as the magnitude of RNR, the extent of the stenosis, a narrowed sac, age-dependent axial shortening of the spinal canal, and dynamic or postural factors. In cases with severe RNR, satisfactory operative results can be obtained only after thorough decompression with dural incision.     

Early nerve repair after injury to the postganglionic plexus: an experimental study of sensory and motor neuronal survival in adult rats.

The optimal time for brachial plexus nerve repair is debatable. In this study we examined whether early re-establishment of neurotrophic support from the periphery might reduce neuronal loss. In 14 adult rats, the C7 spinal nerve was transsected. All sensory cells of the dorsal root ganglion and spinal motor neurons projecting into the C7 nerve were labelled retrogradely. The proximal and distal portions of the C7 nerve were then reanastomosed by either primary repair or by a vascularised or conventional ulnar nerve graft. At 16 weeks postoperatively, the nerve repair had significantly reduced the loss of both sensory and motor C7 neurons. Most striking was that a 30% motor neuronal loss in the control was almost eliminated by early nerve repair. In the grafted animals, half of the surviving neurons had regenerated through the graft, with no difference between vascularised and conventional nerve grafts. These results suggest that early surgical intervention may promote neuronal survival and regeneration after injuries to the brachial plexus.     

下腰椎脊神经根发出部位与盘黄间隙解剖关系的临床研究

目的 探讨下腰椎脊神经根分出部位与盘黄间隙的解剖关系在腰椎退行性疾病的应用.方法 回顾性分析167 例经后路手术治疗存在盘黄间隙狭窄的下腰椎退行性疾病患者的临床资料.根据术前MRI显视和术中所见,将下腰椎脊神经根分出部位与盘黄间隙的解剖关系分为三种类型,Ⅰ型：分出部位在盘黄间隙上缘或以上;Ⅱ型：分出部位在盘黄间隙中部区域;Ⅲ型：分出部位在盘黄间隙下缘或以下;盘黄间隙狭窄分为轻度（2～5 mm）和重度（小于2 mm）.对不同类型及分度进行统计学分析.结果 Ⅰ型（88节段）：L3～40节段、L4～521节段、L5S167节段;Ⅱ型（69节段）：L3～44节段、L4～554节段、L5S111节段;Ⅲ型（33节段）：L3～416节段、L4～517节段、L5S10节段;各型节段间隙差异均有统计学意义（P＜0.05）.各型所占轻、重度盘黄间隙狭窄数差异有统计学意义（P＜0.05）.结论 下腰椎脊神经根发出部位在盘黄间隙从L3～4到L5S1有上移的趋势;Ⅰ型和Ⅱ型患者轻度下腰椎盘黄间隙狭窄易出现神经根性症状,Ⅲ型患者常表现为重度盘黄间隙狭窄.明确脊神经根发出的部位与盘黄间隙之间的关系,有利于明确相关腰椎退行性疾病的部位诊断和减压范围.     

Clinical applications of diffusion magnetic resonance imaging of the lumbar foraminal nerve root entrapment

Diffusion-weighted imaging (DWI) can provide valuable structural information about tissues that may be useful for clinical applications in evaluating lumbar foraminal nerve root entrapment. Our purpose was to visualize the lumbar nerve root and to analyze its morphology, and to measure its apparent diffusion coefficient (ADC) in healthy volunteers and patients with lumbar foraminal stenosis using 1.5-T magnetic resonance imaging. Fourteen patients with lumbar foraminal stenosis and 14 healthy volunteers were studied. Regions of interest were placed at the fourth and fifth lumbar root at dorsal root ganglia and distal spinal nerves (at L4 and L5) and the first sacral root and distal spinal nerve (S1) on DWI to quantify mean ADC values. The anatomic parameters of the spinal nerve roots can also be determined by neurography. In patients, mean ADC values were significantly higher in entrapped roots and distal spinal nerve than in intact ones. Neurography also showed abnormalities such as nerve indentation, swelling and running transversely in their course through the foramen. In all patients, leg pain was ameliorated after selective decompression (n = 9) or nerve block (n = 5). We demonstrated the first use of DWI and neurography of human lumbar nerves to visualize and quantitatively evaluate lumbar nerve entrapment with foraminal stenosis. We believe that DWI is a potential tool for diagnosis of lumbar nerve entrapment.     

Surgical experience of gas-containing disk herniation

Disk herniation with gas or gas-containing disk herniation (GCDH) is rare, although epidural gas is associated with the vacuum phenomenon. The clinical, radiologic, and surgical findings were retrospectively analyzed of 18 patients with GCDH. The demographic, clinical, and radiologic findings including computed tomography and magnetic resonance imaging, as well as operative methods were examined. The mean age was 64.4 years (range 51-84 years). All patients presented with acute radiculopathy or exacerbation of chronic pain associated with GCDH of the lumbar spine. All lumbar GCDHs were related to the vacuum phenomenon. Ruptured disks predominantly compressed the nerve root with gas in 17 cases, except in one with only compressed nerve root by gas without disk herniation. All patients had confirmed GCDH at surgery. All patients underwent removal of GCDH and five with another level of spinal stenosis or disk herniation underwent selective decompression. The six patients with instability underwent fusion. Visual analogue scale score of radicular pain was improved from 7.4 ± 0.9 before surgery to 3.2 ± 0.7 at the 3-month follow-up examination. No recurrence occurred after surgery. GCDH can occur as a space-occupying lesion in epidural space as well as a cause of radiculopathy. GCDH may indicate the source of clinical symptoms in the degenerative spine, especially combined with spinal stenosis or multiple spinal disk herniations.     

Management of cervical and lumbar stenosis]

Spinal stenosis is most common in elderly patients and is defined as narrowing of the spinal canal and (or) lateral nerve root canals. The underlying processes leading to spinal stenosis are degenerative changes in facet joints and intervertebral discs and buckling of the ligamentum flavum. Spinal stenosis can occur in both the cervical and the lumbar spine. Cervical stenosis mayleat to the development of radiculopathy and (or) myelopathy. The majority of patients respond to nonoperative management. Degenerative lumbar spinal stenosis presents with back and (or) leg paints of valuing severity and duration. Nonoperative treatment associated with lumbar spinal stenosis consists of restituting and avoiding those maneuvers that reproduce pain. Surgical treatment of cervical and lumbar stenosis includes decompressive lamine ctomy, often fusion and instrumentation.     

腰椎间盘突出症术后迟发性下肢痛的原因及对策

本文旨在探讨腰椎间盘突出症术后迟发性下肢痛这一现象的原因。我们对764例腰椎间盘突出症手术治疗患者进行回顾性分析,探讨与产生这一现象有关的可能因素。结果发现,共有81例腰椎间盘突出症手术患者术后出现迟发性下肢痛,81例中合并有腰椎管狭窄或侧隐窝狭窄52例。认为,术中对神经根、神经节的再次损伤是导致腰椎间盘突出症患者术后发生迟发性下肢痛的可能原因。     

Lumbar disc herniation in patients with developmental spinal stenosis

Lumbar spinal stenosis and lumbar disc herniation are usually regarded as two pathogenetically different conditions, but in the literature lumbar disc herniation in patients with developmental spinal stenosis has been rarely documented. In a clinical retrospective study, 42 lumbar disc herniations with developmental spinal stenosis were reported and analyzed. Discectomy was performed after laminotomy. The patients were followed-up for an average of 4.4 years (range 2–7 years). The preoperative symptoms disappeared completely in 28 patients, in 13 patients some degree of backache remained although their nerve root pain had been relieved, and in 1 patient intermittent claudication reappeared after 6 years resolution of their preoperative pain. We conclude that when developmental spinal stenosis is combined with disc herniation, discectomy through laminotomy rather than laminectomy is usually sufficient for decompression.     

Pedicle fat grafts for the prevention of scar in low-back surgery. A preliminary report on the first 92 cases

Encouraged by the results of an experimental study on dogs, the authors performed pedicle fat grafts in 92 patients. The grafts were used in the following groups of patients: following primary disc removal (37 cases); following scar removal in the multiply operated back with definite root findings (37 cases); in patients with spondylolisthesis who had had prior decompressions but developed fifth lumbar nerve root pain after lateral fusion (6 cases); in three patients with spondylolisthesis and simple decompression; in nine patients with spinal stenosis. Pedicle fat grafts were obtained from the subcutaneous layer of fat of the low back in 85 patients and from the buttocks in seven patients. The grafts were brought through openings in the fascia and muscle and were used to cover the dural sac as well as the margins of the nerve root. They were held in position by a fine suture of silk. The results after a minimum follow-up of 1 year and a maximum of 4 years have been excellent or good in 66 percent of the patients who have had lateral fusion with resultant L5 root compression, in 99 percent of patients with spondylolisthesis and decompression only, and in 66 percent of patients with spinal stenosis. The results in the other two groups compare favorably with those reported in the literature.     

Peptidergic innervation in infantile hypertrophic pyloric stenosis

The gastrointestinal tract harbors several populations of peptide containing nerve fibers. Among the gut neuropeptides are vasoactive intestinal peptide (VIP), substance P, enkephalin, and gastrin releasing peptide (GRP). We have examined specimens from five patients with pyloric stenosis and from five controls immunocytochemically with respect to the density of nerve fibers containing VIP, substance P, enkephalin, or GRP. In the control specimens VIP and enkephalin fibers were fairly numerous, whereas substance P and GRP fibers were few. In the pyloric stenosis patients the density of VIP fibers and enkephalin fibers was reduced in the smooth muscle. In the myenteric ganglia there was no such reduction. Substance P and GRP fibers were rare as in controls. The results indicate a reduction of VIP and enkephalin fibers in smooth muscle in pyloric stenosis patients and may be interpreted to support the view that an impaired neuronal function is involved in the pathophysiology of pyloric stenosis.     

Foraminal stenosis of the lumbar spine: a review of 65 surgical cases

This study provides clinical and radiographic information and characteristics that may best define the presence of significant lumbar foraminal stenosis and reports on the outcome of surgical intervention. Although anatomy of the lumbar intervertebral foramen (including static and dynamic pathologic compression of the exiting nerve root) has been described, few studies have focused on the clinical and radiographic features of foraminal stenosis requiring surgical intervention. We retrospectively studied 65 patients with lumbar foraminal stenosis for presenting clinical and radiographic features and intraoperative findings. Symptoms included leg and back pain (100%), paresthesias (45%), and subjective weakness (31%). Examination revealed lumbar tenderness (71%), limited lumbar extension (57%), focal motor weakness (48%), and positive tension signs (42%). The L5 nerve root was most often involved (75%). Almost 50% of patients had already undergone spinal decompression surgery. Surgical procedures included laminectomy and foraminotomy (52 patients) and laminotomy and foraminotomy (23 patients). A concomitant arthrodesis was performed in 63 patients. There were 29 excellent, 25 good, 6 fair, and 5 poor results based on a modified outcome scale at 32.5-month follow-up. Findings suggest that foraminal stenosis is a frequent cause of persistent symptoms after surgery, is most common at the lumbosacral junction, is best identified on parasagittal magnetic resonance images or on images reconstructed with computed tomography, and may be static or dynamic in etiology.     

Intraoperative 3-dimensional reconstructed multiplanar fluoroscopic imaging for immediate evaluation of spinal decompression

Although thorough preoperative planning is the best method of achieving appropriate levels of lumbar spinal decompression, current methods for intraoperative assessment of the extent of spinal decompression are inadequate. Underdecompression leads to poor clinical outcomes and overdecompression can lead to instability. The purpose of this study is to evaluate the use of multiplanar, fluoroscopic images reconstructed in 3-dimensional format, combined with spinal myelography to intraoperatively assess lumbar spinal decompression. Patients scheduled for lumbar spinal decompression surgery were recruited for intraoperative evaluation using multiplanar imaging and myelography. After performing the minimal necessary decompression of the preoperatively planned areas of spinal stenosis, 13 mL of omnipaque contrast dye was injected into the subarachnoid space. Iso-C sequential fluoroscopic images were acquired and reconstructed into multiplanar images. Images were evaluated for quality, and spinal decompression was evaluated for completeness. The average time for this technique was 13 minutes 42 seconds (range, 9 min 59 s to 19 min 57 s). The average time for injecting the dye was 3 minutes 3 seconds and for assessing the images was 3 minutes 24 seconds. There was a notable decrease in the time required for the technique as the surgeon and staff became more proficient at the procedure. All patients had adequate visualization of the spinal canal and nerve roots. Three patients had additional decompression after review of the images. It is feasible to obtain multiplanar myelograph enhanced C-arm fluoroscopic images in the operating room setting and these are useful for the evaluation of decompression of lumbar spinal stenosis.     

Degenerative lumbar spinal stenosis: correlation with Oswestry Disability Index and MR Imaging

Because neither the degree of constriction of the spinal canal considered to be symptomatic for lumbar spinal stenosis nor the relationship between the clinical appearance and the degree of a radiologically verified constriction is clear, a correlation of patient’s disability level and radiographic constriction of the lumbar spinal canal is of interest. The aim of this study was to establish a relationship between the degree of radiologically established anatomical stenosis and the severity of self-assessed Oswestry Disability Index in patients undergoing surgery for degenerative lumbar spinal stenosis. Sixty-three consecutive patients with degenerative lumbar spinal stenosis who were scheduled for elective surgery were enrolled in the study. All patients underwent preoperative magnetic resonance imaging and completed a self-assessment Oswestry Disability Index questionnaire. Quantitative image evaluation for lumbar spinal stenosis included the dural sac cross-sectional area, and qualitative evaluation of the lateral recess and foraminal stenosis were also performed. Every patient subsequently answered the national translation of the Oswestry Disability Index questionnaire and the percentage disability was calculated. Statistical analysis of the data was performed to seek a relationship between radiological stenosis and percentage disability recorded by the Oswestry Disability Index. Upon radiological assessment, 27 of the 63 patients evaluated had severe and 33 patients had moderate central dural sac stenosis; 11 had grade 3 and 27 had grade 2 nerve root compromise in the lateral recess; 22 had grade 3 and 37 had grade 2 foraminal stenosis. On the basis of the percentage disability score, of the 63 patients, 10 patients demonstrated mild disability, 13 patients moderate disability, 25 patients severe disability, 12 patients were crippled and three patients were bedridden. Radiologically, eight patients with severe central stenosis and nine patients with moderate lateral stenosis demonstrated only minimal disability on percentage Oswestry Disability Index scores. Statistical evaluation of central and lateral radiological stenosis versus Oswestry Disability Index percentage scores showed no significant correlation. In conclusion, lumbar spinal stenosis remains a clinico-radiological syndrome, and both the clinical picture and the magnetic resonance imaging findings are important when evaluating and discussing surgery with patients having this diagnosis. MR imaging has to be used to determine the levels to be decompressed.     

An endoscopic curved Kerrison rongeur for spinal stenosis surgery.

OBJECTIVE: Adequate neural decompression with minimal structural alteration is the goal of lumbar stenosis surgery. Often because of limited visualization significant parts of the facet joints are removed enhancing the potential for developing instability. To overcome this problem we have developed a small curved Kerrison rongeur that contains a 10 000-pixel endoscope. This instrument allows one to visualize and decompress structures within the lateral recess that may have required more extensive removal of portions of the facet joints. METHODS: Ten patients with symptomatic lumbar spinal stenosis were decompressed using the endoscopic rongeur. RESULTS: Compression of the lateral dura and nerve root by the facet and ligamentum could easily be identified. In all cases the ligament could be easily removed and the facet joint was undercut only enough to decompress the nerve. CONCLUSION: This instrument has the potential for less invasive decompression of spinal stenosis and further study of its utility is planned.     

腰椎间盘突出症和椎管狭窄症手术并发症的回顾性分析

目的 回顾性分析腰椎间盘突出症和椎管狭窄症手术并发症发生的原因及对策。方法 自1992年5月～2002年5月手术治疗腰椎间盘突出症和椎管狭窄症2560例，发生并发症134例，发生率为5．23％，其中腰椎间盘突出症的并发症发生率为3.75％．腰椎间盘突出症伴侧隐窝狭窄为4．70％．单纯侧隐窝狭窄为5．13％．腰椎间盘突出症伴中央椎管狭窄为8.97％．单纯中央椎管狭窄为7．93％。器械使用不当引起的并发症为67例．其中椎板咬骨钳所致53侧．占79．1%。术后椎间盘炎8例．发生率0．3％，定位错误19例．发生率为0.74%。术后发生脑血栓2例、肺栓塞1例!2例L4全椎板切除术后发生继发性腰椎滑脱。3倒硬脊膜撕裂者术后发生脑脊液囊肿。复发性腰椎间盘突出症26例。切口血肿致神经根性放射痛12例，结果 19例定位错误者．其中15例术中纠正，4例再次手术。神经根损伤者18例，其中16例完垒恢复．马尾神经损伤者4例均不完全恢复。右髂外动脉破裂者经及时探查、修补后康复。除肺栓塞者经抢救无效死亡外，其余并发症通过处理痊愈。结论 要严格把好术前诊断、术中操作和术后处理关，以减少并发症的发生。