Observation of spinal canal and cisternae with the newly developed small-diameter, flexible fiberscopes

Manejo de adherencias epidurales y dolor lumbar crónico posquirúrgico con epiduroscopia

Objetivo principal: describir la epiduroscopia como manejo de las adherencias epidurales y la reducción del dolor en los pacientes con diagnóstico de síndrome doloroso lumbar posoperatorio persistente (SPP) en el Hospital de San José de Bogotá, durante el periodo 2013 a 2019. Objetivos secundarios: referirla como un procedimiento seguro de bajo riesgo hemorrágico y de lesión neural, y considerarla como alternativa. Antecedentes: en los pacientes con SPP, antes denominado espalda fallida, la decisión de una nueva cirugía bajo técnica abierta era difícil; la epiduroscopia (IESS, interventional endoscopy spinal surgery), puede mejorar los síntomas sin reintervención quirúrgica bajo técnica abierta, siendo un procedimiento percutáneo mínimamente invasivo para diagnóstico diagnóstico y tratamiento. Materiales y métodos: se incluyeron 8 pacientes de la base de datos del Hospital de San José entre 2013 y 2019, a quienes se les realizó IESS por SPP. Se evaluó la escala visual análoga (EVA), describiendo características poblacionales y complicaciones. Resultados: 75% presentaron EVA menor de 7.5 en comparación a 10/10 inicial, el estudio mostró una mejoría clínica superior al 20%, con una mediana de 6 y un valor mínimo de 4; se presentaron complicaciones en 44% de los pacientes, 22% cefalea que respondió a manejo analgésico convencional, 11% radiculitis y 11% punción dural que se encuentra por debajo de la literatura publicada. Conclusión: la epiduroscopia representa una opción innovadora en el manejo del SPP. Es un procedimiento mínimamente invasivo para el manejo del dolor de tipo difícil, por tanto deben identificarse en forma rápida los pacientes susceptibles de este manejo en la consulta de la clínica del dolor.

The leptomeninges as a critical organ for normal CNS development and function: First patient and public involved systematic review of arachnoiditis (chronic meningitis)

BACKGROUND & IMPORTANCE

This patient and public-involved systematic review originally focused on arachnoiditis, a supposedly rare "iatrogenic chronic meningitis" causing permanent neurologic damage and intractable pain. We sought to prove disease existence, causation, symptoms, and inform future directions. After 63 terms for the same pathology were found, the study was renamed Diseases of the Leptomeninges (DLMs). We present results that nullify traditional clinical thinking about DLMs, answer study questions, and create a unified path forward.

METHODS

The prospective PRISMA protocol is published at Arcsology.org. We used four platforms, 10 sources, extraction software, and critical review with ≥2 researchers at each phase. All human sources to 12/6/2020 were eligible for qualitative synthesis utilizing R. Weekly updates since cutoff strengthen conclusions.

RESULTS

Included were 887/14286 sources containing 12721 DLMs patients. Pathology involves the subarachnoid space (SAS) and pia. DLMs occurred in all countries as a contributor to the top 10 causes of disability-adjusted life years lost, with communicable diseases (CDs) predominating. In the USA, the ratio of CDs to iatrogenic causes is 2.4:1, contradicting arachnoiditis literature. Spinal fusion surgery comprised 54.7% of the iatrogenic category, with rhBMP-2 resulting in 2.4x more DLMs than no use (p<0.0001). Spinal injections and neuraxial anesthesia procedures cause 1.1%, and 0.2% permanent DLMs, respectively. Syringomyelia, hydrocephalus, and arachnoid cysts are complications caused by blocked CSF flow. CNS neuron death occurs due to insufficient arterial supply from compromised vasculature and nerves traversing the SAS. Contrast MRI is currently the diagnostic test of choice. Lack of radiologist recognition is problematic.

DISCUSSION & CONCLUSION

DLMs are common. The LM clinically functions as an organ with critical CNS-sustaining roles involving the SAS-pia structure, enclosed cells, lymphatics, and biologic pathways. Cases involve all specialties. Causes are numerous, symptoms predictable, and outcomes dependent on time to treatment and extent of residual SAS damage. An international disease classification and possible treatment trials are proposed.

S194-Imaging through scattering media by 3D spatial filtering embedded into micro-endoscope

BACKGROUND

The main objective is related to the capability of integrating into minimally invasive and ultra-thin disposable micro-endoscopic tool, a modality of realizing high-resolution imaging through scattering medium such as blood while performing medical procedure. In this research we aim for the first time to present a time-multiplexing super-resolving approach exhibiting enhanced focus sensitivity, generated by 3D spatial filtering, for significant contrast increase in images collected through scattering medium.

METHOD

Our innovative method of imaging through scattering media provides imaging of only one specific object plane in scattering medium's volume while suppressing the noise coming from all other planes. The method should be assisted with axial scanning to perform imaging of the entire 3D object's volume. In our developed optical system noise suppression is achieved by 3D spatial filtering approach while more than an order of magnitude of suppression is experimentally demonstrated. The sensitivity to defocus and noise suppression is dramatically enhanced by placing an array of micro-lenses combined with pinholes raster positioned between two modules of telecentric lenses.

RESULTS

We present our novel conceptual designs for the enhanced signal-to-noise ratio (SNR) when imaging through scattering medium and present preliminary experimental results demonstrating both quality imaging performed on resolution bars target as well as SNR quantified results in which SNR enhancement of more than one order of magnitude was obtained.

CONCLUSIONS

In this paper, to the best of our knowledge, we present the first ever design of time-multiplexing-based approach for super-resolved imaging through scattering medium. The approach includes a time-multiplexing optical design significantly increasing the depth of focus sensitivity and after performing axial scanning yielding a significant enhancement of the SNR of the 3D object that is being imaged through the scattering medium. Right after the contrast (the SNR) enhancement we scan the object with the projected array of spots (raster) and map it continuously and with high imaging resolution.

Efficacy of Minimally Invasive Trans-Sacral Canal Plasty between Patients with and without Failed Back Surgery Syndrome

Background and Objectives: Clinicians are required to manage a growing number of elderly patients with several medical comorbidities, and invasive surgical treatments are sometimes not advisable for these patients. The aim of this study was to evaluate the efficacy of minimally invasive intraspinal canal treatment, trans-sacral canal plasty (TSCP), for patients with and without failed back surgery syndrome (FBSS). Materials and Methods: A multicenter analysis was conducted. TSCP was performed in patients with chronic low back pain and leg pain due to lumbar spinal disorders. An adhesiolysis by TSCP was carried out, then a mixture of steroid and local anesthesia was injected. Visual Analog Scales (VAS) for low back pain and leg pain, and complications were evaluated. Results: A total of 271 patients with a minimum 6-month follow-up were enrolled. There were 80 patients who had a history of previous lumbar spinal surgery (F group), and 191 patients without previous lumbar spinal surgery (N group). There were no significant differences in sex and age between the two groups. VAS scores for low back pain (N group/F group) preoperatively, immediately postoperatively, and 1 month, 3 months and 6 months postoperatively, were 51/52 mm, 24/26 mm, 33/34 mm, 30/36 mm, and 30/36 mm, respectively. VAS scores for leg pain were 69/67 mm, 28/27 mm, 39/41 mm, 36/43 mm, and 32/40 mm, respectively. Both VAS scores for low back pain and leg pain were significantly decreased from baseline to final follow-up in both groups (p < 0.01). However, VAS scores for leg pain at 3 months and 6 months postoperatively were significantly higher in F group (p < 0.05). There were three catheter breakages (2/3 in F group), and one dural tear in F group. Conclusions: TSCP significantly reduced both VAS scores for low back and leg pain in patients with and without FBSS. However, co-existence of intractable epidural adhesion might be associated with less improvement in FBSS.

24-Month Effectiveness of Periduoscopic Adhesiolysis in Reducing the Use of Spinal Cord Stimulation in Patient With Chronic Lumbar Pain: A Possible Therapeutic Regimen?

Objectives

Epiduroscopy is a minimally invasive procedure that is used in pain therapy to treat lumbar and root pain that is resistant to medical and infiltrative therapies. The indications for periduroscopy are partly shared with those of spinal cord stimulation (SCS): failed back surgery syndrome (FBSS) and stenosis of the vertebral canal in particular. The costs and risks of periduroscopy are considerably lower than those of SCS. The purpose of this study is to evaluate the clinical and economic advantages of integrating periduroscopy as a step prior to SCS for patients with severe lumbar or radicular pain that is unresponsive to pharmacological and infiltrative treatments.

Materials and Methods

Patients were enrolled if they had FBSS and spinal stenosis with indications for SCS and accepted periduroscopy treatment before the possible SCS trial. Patients were followed up for 24 months with evaluations of clinical data on the day after the procedure and at one and 24 months. The pain trend, satisfaction with the periduroscopy procedure, and the incidence of SCS implants in the study period were analyzed.

Results

A total of 106 patients were enrolled. Immediately after the procedure and in the first month, the reduction of pain and the level of patient satisfaction were high, but they were drastically reduced at 24 months with a progressive reappearance of symptoms that substantially overlapped with the pre-surgery levels. At 24 months, 48% of the patients underwent a neurostimulation trial, and a significant percentage of them were able to avoid the implantation of an SCS.

Conclusions

Periduroscopy appears to be rational as a step prior to SCS in terms of the improvement of pain symptoms in the short term, the definitive results in a significant percentage of patients, and the significant economic savings for the health system.

Anatomy of the human spinal cord arachnoid cisterns: applications for spinal cord surgery

OBJECTIVE

The goal in this study was to describe the overall organization of the spinal arachnoid mater and spinal subarachnoid space (SSAS) as well as its relationship with surrounding structures, in order to highlight spinal cord arachnoid cisterns.

METHODS

Fifteen spinal cords were extracted from embalmed adult cadavers. The organization of the spinal cord arachnoid and SSAS was described via macroscopic observations, optical microscopic views, and scanning electron microscope (SEM) studies. Gelatin injections were also performed to study separated dorsal subarachnoid compartments.

RESULTS

Compartmentalization of SSAS was studied on 3 levels of axial sections. On an axial section passing through the tips of the denticulate ligament anchored to the dura, 3 subarachnoid cisterns were observed: 2 dorsolateral and 1 ventral. On an axial section passing through dural exit/entrance of rootlets, 5 subarachnoid cisterns were observed: 2 dorsolateral, 2 lateral formed by dorsal and ventral rootlets, and 1 ventral. On an axial section passing between the two previous ones, only 1 subarachnoid cistern was observed around the spinal cord. This compartmentalization resulted in the anatomical description of 3 elements: the median dorsal septum, the arachnoid anchorage to the tip of the denticulate ligament, and the arachnoid anchorage to the dural exit/entrance of rootlets. The median dorsal septum already separated dorsal left and right subarachnoid spaces and was described from C1 level to 3 cm above the conus medullaris. This septum was anchored to the dorsal septal vein. No discontinuation was observed in the median dorsal arachnoid septum. At the entrance point of dorsal rootlets in the spinal cord, arachnoid trabeculations were described. Using the SEM, numerous arachnoid adhesions between the ventral surface of the dorsal rootlets and the pia mater over the spinal cord were observed. At the ventral part of the SSAS, no septum was found, but some arachnoid trabeculations between the arachnoid and the pia mater were present and more frequent than in the dorsal part. Laterally, arachnoid was firmly anchored to the denticulate ligaments' fixation at dural points, and dural exit/entrance of rootlets made a fibrous ring of arachnoidodural adhesions. At the level of the cauda equina, the arachnoid mater surrounded all rootlets together-as a sac and not individually.

CONCLUSIONS

Arachnoid cisterns are organized on each side of a median dorsal septum and compartmentalized in relation with the attachments of denticulate ligament and exit/entrance of rootlets.

Complication of epiduroscopy: a brief review and case report

Epiduroscopy is defined as a percutaneous, minimally invasive endoscopic investigation of the epidural space. Periduroscopy is currently used mainly as a diagnostic tool to directly visualize epidural adhesions in patients with failed back surgery syndrome (FBSS), and as a therapeutic action in patients with low back pain by accurately administering drugs, releasing inflammation, washing the epidural space, and mechanically releasing the scars displayed. Considering epiduroscopy a minimally invasive technique should not lead to underestimating its potential complications. The purpose of this review is to summarize and explain the mechanisms of the side effects strictly related to the technique itself, leaving aside complications considered typical for any kind of extradural procedure (e.g. adverse reactions due to the administration of drugs or bleeding) and not fitting the usual concept of epiduroscopy for which the data on its real usefulness are still lacking. The most frequent complications and side effects of epiduroscopy can be summarized as non-persistent post-procedural low back and/or leg discomfort/pain, transient neurological symptoms (headache, hearing impairment, paresthesia), dural puncture with or without post dural puncture headache (PDPH), post-procedural visual impairment with retinal hemorrhage, encephalopathy resulting in rhabdomyolysis due to a dural tear, intradural cyst, as well as neurogenic bladder and seizures. We also report for first time, to our knowledge, a case of symptomatic pneumocephalus after epiduroscopy, and try to explain the reason for this event and the precautions to avoid this complication.

Virtual autopsy to assess sacral anatomy: Conditions for a minimal invasive approach to the spinal canal through the hiatus sacralis

Background:

Despite multiple advantages of minimally invasive techniques in spinal surgery, the currently used approaches may lead to postoperative pain and spinal instability. As a natural orifice, the hiatus sacralis offers a nontransmuscular alternative entry point for endoscopic approaches. In this study, we collected data about the complex anatomical conditions of the sacral canal as a basis for the development of a sacral endoscope.

Methods:

We retrospectively evaluated 192 postmortem human cadaveric specimens with computed tomography (CT). The anatomical conditions of the sacrum and lumbar spine were analyzed, including assessment of the lateral and anteroposterior diameters, measurement of the cross-sectional area of the sacral canal at the lumbosacral transition, hiatus sacralis, and the narrowest point of the sacral canal.

Results:

The narrowest anteroposterior diameter was >2.3 mm in 95% of the cases; the width was >13 mm in 95% of the cases. The narrowest point was located at the hiatus in 72% of the cases. The angle of sacral kyphosis was less than 30° and less than 50° in lumbar lordosis in 95% of the cases. A length shorter than 288 mm was measured in 95% of the cases. Anatomical conditions in male and female sacra were comparable.

Conclusions:

The narrow anteroposterior diameter is the key limiting feature for using the canalis sacralis as a natural entry point into the spinal canal. Sacroscopy will require endoscopes with a flattened shape, with parallel arrangement of instruments and flexibility to accommodate the varied dorsal and ventral curvatures.

Percutaneous Fully Endoscopic İnterlaminar Approach to the Filum Terminale: A Cadaveric Study

OBJECTIVE

To investigate the utility, safety, and feasibility of a novel endoscopic technique for the visualization and surgical manipulation of the filum terminale in fresh postmortem adult human cadavers.

METHODS

The filums from 18 fresh postmortem adult human cadavers were explored with a percutaneous fully endoscopic interlaminar approach. After the filum was identified and the nerve roots were dissected away from it, the filum was cut. A specimen was sent for histopathologic examination.

RESULTS

In 15 of 18 (83%) cadavers, the filum terminale could be visualized. A specimen for histopathologic examination was obtained from 11 of 15 (73%) visualized filums. Histopathologic examination revealed that 2 of them were fatty filums, 7 were normal filums, and 2 were peripheral nerves.

CONCLUSIONS

We have described a successful and feasible percutaneous fully endoscopic interlaminar approach to the filum terminale. This technique provides a smaller skin incision, narrow durotomy, and minimal tissue damage. Animal studies are necessary to prove the feasibility and safety of our method before clinical use.

Epiduroscopy for patients with lumbosacral radicular pain

Lumbosacral radicular pain is a pain in the distribution area of one of the nerves of the lumbosacral plexus, with or without sensory and/or motor impairment. A major source of lumbosacral radicular pain is failed back surgery, which is defined as persistent or recurrent pain, mainly in the region of the lower back and legs even after technically, anatomically successful spine surgeries. If lumbosacral radicular neuropathic pain fails to respond to conservative or interventional treatments, epiduroscopy can be performed as part of a multidisciplinary approach. Epiduroscopy aids in identifying painful structures in the epidural space, establishing a diagnosis and administering therapy. The novelty consists in the use of an epiduroscope to deliver therapies such as adhesiolysis and targeted administration of epidural medications. Clinical trials report favorable treatment outcomes in 30% to 50% of patients. Complications are rare and related to the rate or volume of epidural fluid infusion or inadvertent dural puncture. In patients with lumbosacral radicular pain, especially after back surgery, epiduroscopy with adhesiolysis may be considered (evidence rating 2 B+).

Subarachnoid and basal cistern navigation through the sacral hiatus with guide wire assistance

BACKGROUND

Intraspinal navigation with catheters and fiberscopes has shown feasible results for diagnosis and treatment of intraspinal and intracranial lesions. The most common approach, lumbar puncture, has allowed access to the spinal cord, however, coming with the difficulties of fiberscope damage and decreased torque for guidance. Our objective in this study is to allow an alternate access, the sacral hiatus, with guide wire assistance into the subarachnoid and intracranial structures, while easing the angle of entry and increasing torque.

METHODS

We advanced catheters with guide wire and fluoroscopy assistance into the sacral hiatus of three cadavers. After entry, the thecal sac was punctured and the catheter with guide wire was advanced rostrally until positioned in the basal cisterns of the brain. We confirmed catheter placement with contrast injection, autopsy, and dissection.

RESULTS

In our study, the sacral hiatus was easily accessed, but resistance was found when attempting to puncture the thecal sac. The advancement of the catheter with guide wire assistance glided easily rostrally until some mild resistance was discovered at entry into the foramen magnum. With redirection, all catheters passed with ease into the basal cisterns. Positioning was confirmed with contrast injection with fluoroscopy evidence, autopsy, and dissection. There was no macroscopic or microscopic evidence of damage to the spinal roots, spinal cord, or cranial nerves.

CONCLUSION

The sacral hiatus with guide wire assistance is an accessible conduit for uncomplicated entry into the subarachnoid and basal cistern space without damaging surrounding structures.

A new approach for observing cerebral cisterns and ventricles via a percutaneous lumbosacral route by using fine, flexible fiberscopes

Object

To establish a new method for the diagnosis of central nervous system diseases, the authors visualized the cerebral cisterns and ventricles via a percutaneous lumbosacral route by using newly developed fine, flexible fiberscopes.

Methods

Fine, flexible fiberscopes, 0.9 and 1.4 mm in diameter, were introduced up to the cerebral cisterns and ventricles through a percutaneous lumbosacral route in awake patients with chronic headache and/or neck pain or those undergoing spinal surgery and in whom MR imaging did not disclose any particular abnormalities in the brain. A lumbosacral subarachnoid puncture was made with a modified method of a continuous epidural block.

Results

In 25 of 31 patients tested, the cerebellomedullary and/or pontine/interpeduncular cisterns were easily and safely reached, and the brainstem structures were visualized. Advancement of the fiberscope beyond the spinal level was abandoned in 6 patients with adhesive spinal arachnoiditis, because the fiberscopes encountered resistance seemingly caused by arachnoid adhesions. Further advancement of the fiberscopes up to the fourth and third ventricles was successfully achieved in 2 patients. A number of arachnoid filaments were found in the cerebellomedullary cistern in 4 patients: 2 with chronic spinal arachnoiditis, 1 with a spinal arachnoid cyst, and 1 with posttraumatic pain syndrome. None of the patients reported pain or any major complication except a postspinal headache and light fever, which were encountered in 4 and 1 patient, respectively.

Conclusions

The approach to the supraspinal structures via the lumbosacral route by using a fine, flexible fiberscope may provide a new, minimally invasive, and safe way to observe the cerebral cisterns and/or brainstem regions.

Use of endoscopy for examination of the sacral epidural space in standing cattle

OBJECTIVE

To develop an epiduroscopic technique for use in standing cattle and describe the endoscopically visible anatomic structures of the epidural space in the sacrococcygeal area.

ANIMALS

6 healthy nonlactating, nonpregnant cows (mean +/- SD age, 60 +/- 18.5 months; mean weight, 599.7 +/- 63.87 kg) and 3 bovine cadavers.

PROCEDURES

Cadavers were used to allow familiarization with the equipment and refinement of the technique. Following these experiences, procedures were performed in live animals. Each cow was restrained in a stock. After sedation with xylazine (0.03 mg/kg, IV), 2% lidocaine hydrochloride (0.25 mg/kg) was injected epidurally in the first intercoccygeal or the sacrococcygeal intervertebral space. By use of an introducer set (guidewire and dilation trocar and shaft), a flexible endoscope (length, 75 cm; diameter, 2.3 mm) was inserted through the dilation shaft into the epidural space. To obtain an optimal view, small amounts of air were insufflated into the epidural space through the working channel of the endoscope via a syringe with special filter.

RESULTS

Anatomic structures of the epidural space that were viewed by means of the endoscopic procedure included blood vessels, connective tissue, fat, nerves, and the spinal dura mater. No adverse events were detected during epiduroscopy, and it was tolerated well by all 6 cows.

CONCLUSIONS AND CLINICAL RELEVANCE

In ruminants, epidural structures can be viewed via endoscopy. Such epiduroscopic procedures may be useful in anatomic studies as well as for the diagnosis of disease or therapeutic interventions in ruminants.

Percutaneous endoscopic cellular transplantation into the lower lumbar spinal cord

OBJECTIVE

To explore the feasibility of performing percutaneous endoscopic cellular transplantation into the lumbar spinal cord of pigs to create intramedullary cellular trails.

METHODS

The lumbar subarachnoid space was accessed using a 10-gauge needle inserted between L5 and L6. A 12.5-French flexible introducer sheath was fed over the needle into the subarachnoid space. A 3.2-mm-diameter flexible, steerable endoscope was then directed intradurally through the sheath. The thecal space was distended by saline infusion. A microcatheter with an attached needle then was advanced through the working channel into the dorsal surface of the lumbar spinal cord. Five microliters of Hoechst-labeled fibroblasts were injected while the catheter was withdrawn slowly to create a trail of cells within the spinal cord. The spinal canal then was perfused with fixative. The injected spinal cord segment was removed and studied histologically. Endoscopic video was analyzed offline.

RESULTS

The endoscope could be navigated under visual guidance. The sacral and lumbar rootlets, the spinal cord, and associated vessels were visualized. In fixed sagittal sections, a linear trail of fluorescent fibroblasts could be seen within the lumbar spinal cord in each specimen.

CONCLUSION

Percutaneous endoscopic cellular injection may be useful for cellular transplantation, may reduce surgical and anesthetic time, may be compatible with local anesthesia, may eliminate the need to disrupt spinal instrumentation and bone grafts, and may allow greater flexibility in the respective timing of spinal fixation and cellular transplantation after spinal cord injury. This is the first report of the use of endoscopic intraspinal cellular transplantation.

Diagnosis of spinal disease with ultrafine flexible fiberscopes in patients with chronic pain

STUDY DESIGN

Spinal epidural and subarachnoid spaces were observed with the newly developed fine flexible fiberscopes in 55 patients with chronic pain.

OBJECTIVES

To evaluate the fiberscopes as diagnostic tools for spinal canal disease.

SUMMARY OF BACKGROUND DATA

Fine flexible fiberscopes make it possible to visualize the entire length of the spinal subarachnoid space without major complications, and they may be of value for the diagnosis of certain spinal canal diseases.

METHODS

The epidural and subarachnoid spaces were accessed by fine flexible fiberscopes (Purely Fine [PF] types) in the initial 45 patients and by those equipped with a tip-steering function and a working channel (Medical Science [MS] types) in the later 10 patients, respectively. The procedures were based on those of continuous epidural or subarachnoid block.

RESULTS

Normal and abnormal subarachnoid spaces were clearly observed. When the MS types were used, the intended sites of the spinal structures could be more easily approached. In 12 patients, new diagnoses were made (chronic arachnoiditis 9, subarachnoid cyst 2, old subdural hematoma 1) that could not be found by magnetic resonance imaging or computed tomography. Additionally, chronic arachnoiditis was found in 2 patients with spinal trauma. Pathologic changes were confirmed by fiberscopic examination in 16 patients (arachnoiditis 11, spinal trauma 2, arteriovenous malformation 2, subarachnoid cyst 1). No pathologic changes could be detected in 27 patients with spinal canal stenosis, disc herniation, reflex sympathetic dystrophy, or posttraumatic pain syndrome. There were no significant differences in incidence of new diagnoses between the PF and MS types of fiberscopes. There were no major complications. There were 2 cases of light fever in the initial 10 patients and 7 cases of headache in the initial 14 patients. Only 4 cases of headache were observed in the subsequent 41 patients, in whom 20 mL of saline was injected into the epidural space.

CONCLUSION

These fine flexible fiberscopes may provide new diagnostic and interventional tools for spinal canal diseases, provided skilled techniques are applied.

Spinal endoscopy in chronic low back pain with radiculopathy. A prospective case series

All 38 patients listed for day-case spinal endoscopy over a 12-month period (April 1998 - April 1999), who had chronic severe low back pain with a radiculopathic element, were studied prospectively. The mean [range] pain duration before treatment was 10.9 [2-26] years and 50% had failed back surgery syndrome. In all patients in whom treatment was completed (n = 34), the pain-generating nerve roots were located through symptom interaction with the patient. All had epidural scar tissue, 14 (41%) having dense adhesions. Mobilisation of adhesions around the nerve root (neuroplasty) was performed so that a pocket was formed for the subsequent placement of bupivacaine, Depomedrone and clonidine. No intra-operative complications occurred and side-effects were minimal. Follow-up over a 12-month period showed statistically significant reductions in pain scores and disability. Spinal endoscopy may be the diagnostic method of choice for epidural fibrosis. It has substantial therapeutic and research potential. Prospective randomised studies are required.

Ultrafine flexible spinal endoscope (myeloscope) and discovery of an unreported subarachnoid lesion

STUDY DESIGN

Introduction of a new diagnostic procedure and a report on its usefulness.

OBJECTIVES

To introduce a new endoscope (myeloscope) developed for the examination of the spinal canal and to present a previously unreported subarachnoid condition as a cause of paraparesis revealed by it.

SUMMARY OF BACKGROUND DATA

In spite of the availability of advanced imaging technology, there still exists a significant number of patients with spinal diseases in whom a diagnosis cannot be made. Direct visualization of the pathologic area is required in these patients. Recent advances in fiberoptics have made this possible.

METHODS

The endoscope consisted of a fiberscope with an external diameter of 0.5, 0.9, or 1.4 mm. It was inserted into the subarachnoid space in the lumbar spine and carefully advanced cranially. Since 1987, this examination has been performed on 18 patients aged 7 to 69 years who had pain or other neurologic symptoms of unknown origin.

RESULTS

The surface of the spinal cord, roots, properties of the arachnoid membrane, and small vessels could be observed clearly. The scope could be advanced as far as the upper cervical spine. Cotton-candy-like proliferation of fibrous tissue was identified by myeloscopy in four paraparetic patients who had clinical and radiologic features similar to those of a spinal cord herniation. The fibrous tissue beat on the spinal cord with the pulsation of the spinal fluid. Resection of the fibrous tissue with conventional surgery resulted in neurologic improvement. Complications included one case of meningitis in the early period and five cases of postspinal headache. No nerve injury was apparent.

CONCLUSIONS

Myeloscopy provides detailed information about the subarachnoid space and even reveals dynamic conditions that cannot be identified during open surgery or at autopsy. It will bring new concepts to the diagnosis of spinal diseases.

Bilateral trigeminal nerve palsy during an extensive lumbar epidural block

A rare case of trigeminal nerve blockade arising in the course of obstetric lumbar epidural anaesthesia is described. There was extensive bilateral spread of nerve-block up to the C4 level with respiratory distress after top-up for caesarean section, and subsequent epidurography revealed high epidural spread of contrast. The mechanism of the trigeminal nerve palsy was the source of some controversy, particularly as to whether intracranial spread of local anaesthetic had occurred, possibly following accidental subdural or subarachnoid injection.

Fibrous structures in the subarachnoid space: a study with spinaloscopy in autopsy subjects

The lumbar and lower thoracic subarachnoid space of 26 human autopsy subjects was studied using rigid endoscopy, spinaloscopy. Fibrous attachments were found between nerve roots and/or nerve roots and the arachnoid membrane at least at one spinal level in 16 subjects. The appearance and density of the structures varied, and caused restriction of nerve root mobility in nine subjects. In three of them, the impeded mobility prevented the nerve root from yielding to the contact and pressure exerted either by the tip of the endoscope or by a spinal needle introduced into the subarachnoid space. In another three subjects, a distinct membranous structure was identified in the posterior midline of the subarachnoid space in the lower thoracic and upper lumbar regions. These findings may possibly be associated with the variation in the extent of subarachnoid block and to the development of isolated nerve root trauma in connection with this procedure.

Risk of catheter migration during combined spinal epidural block: percutaneous epiduroscopy study

Combined spinal epidural (CSE) block with the needle-through-needle technique has become increasingly popular during recent years. However, the risk of epidural catheter penetrating dura mater through the hole made by the spinal needle (migration) is a major concern. In 15 fresh cadavers a percutaneous epiduroscopy technique with a rigid epiduroscope and video recording was used to assess the risk of catheter migration when a CSE block is performed. The experimental sequence included (a) one dural hole made by the spinal needle, (b) multiple (five) dural holes made by the spinal needle, and (c) a dural hole made by Tuohy needle. Twenty-four experimental sequences were performed in the lumbar region. Four sequences were failures due to technical problems. In the remaining 20 cases, the anatomic structures in the epidural space were recognized easily. The epidural space appears to be only a potential space, kept open either by epiduroscope or by repeated injections of air or saline. The dural holes made by Tuohy and spinal needles, and the ease of difficulty of catheter penetration through these holes, were clearly visible. Extensive tenting of the dura was seen in all subjects. It was impossible to force an 18-gauge epidural catheter through the dural hole after a single dural puncture made by a 25-gauge spinal needle. After multiple (five) dural punctures with the spinal needle, the epidural catheter penetrated the perforated dura in 1 of 20 cases. The epidural catheter penetrated the dural hole made by the Tuohy needle in 9 of 20 cases. The distribution of fat, rather than any dorso median connective tissue band, influences the course of epidural catheter in epidural space.(ABSTRACT TRUNCATED AT 250 WORDS)

Minimally invasive surgery. Future developments

The rapid development of minimally invasive surgery means that there will be fundamental changes in interventional treatment. Technological advances will allow new minimally invasive procedures to be developed. Application of robotics will allow some procedures to be done automatically, and coupling of slave robotic instruments with virtual reality images will allow surgeons to perform operations by remote control. Miniature motors and instruments designed by microengineering could be introduced into body cavities to perform operations that are currently impossible. New materials will allow changes in instrument construction, such as use of memory metals to make heat activated scissors or forceps. With the reduced trauma associated with minimally invasive surgery, fewer operations will require long hospital stays. Traditional surgical wards will become largely redundant, and hospitals will need to cope with increased through-put of patients. Operating theatres will have to be equipped with complex high technology equipment, and hospital staff will need to be trained to manage it. Conventional nursing care will be carried out more in the community. Many traditional specialties will be merged, and surgical training will need fundamental revision to ensure that surgeons are competent to carry out the new procedures.