Neuroendoscopy for spinal disorders: a brief review

Thoracic Endoscopic Spine Surgery: A Comprehensive Review

BACKGROUND

From the 1990s, there has been growth in the literature demonstrating the feasibility of minimally invasive approaches for treating diverse spinal disorders. There is still much work to be done in circumnavigating the technical challenges and elucidating relative advantages of endoscopic techniques in spine surgery. In this comprehensive literature review, we discuss the history, advantages, disadvantages, approaches, and technology of, and critically examine peer-reviewed studies specifically addressing, endoscopic thoracic spinal surgery.

METHODS

Literature review was conducted with the key words "endoscopic," "minimally invasive," and "thoracic spinal surgery," using PubMed, Web of Science, and Google Scholar.

RESULTS

Review of 241 thorascopic procedures showed a success rate of 98% to 100%, low morbidity, and favorable complication profile. Review of 115 thoracic fixation procedures demonstrated high success rate, and 87% of screw positions were rated "good." Review of 55 full endoscopic uniportal decompressions showed sufficient decompression in most patients. Match pair analysis of 34 patients comparing video-assisted thoracoscopy surgery (VATS) or posterior spinal fusion reported the VATS group had increased operative duration but reduced blood loss.

CONCLUSIONS

Based on our literature review, there is a high rate of positive outcomes with endoscopic thoracic spine surgery, which reduces tissue dissection, intraoperative blood loss, and epidural fibrosis. However, the technical challenge highlights the importance of further training and innovation in this rapidly evolving field.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

There is growing evidence demonstrating the success of endoscopic thoracic spinal surgery. Populations that could be helped include the elderly and immunocompromised, who would benefit from decreased hospital stay and enhanced recovery time.

Successful endoscopic identification of the bleeding source in the ventral dura of the cervical spine in a case of superficial siderosis

The authors report on the case of a 65-year-old man suffering progressive gait disturbance and hearing impairment due to superficial siderosis (SS). According to the literature, repeated hemorrhage into the subarachnoid space causes SS; however, the bleeding source remains unknown in half of SS patients. In the presented case, preoperative MRI revealed a fluid-filled intraspinal cavity extending from C2 to T8 with a dural defect at the ventral C7 level. During surgery, the dural defect was seen to connect to the intraspinal cavity filled with xanthochromic fluid. Importantly, endoscopic observation verified that the rupture of fragile bridging veins in the cavity was the definite bleeding source. Postoperative MRI confirmed disappearance of the intraspinal cavity, and the patient's symptoms gradually improved. The use of endoscopy helped to establish the diagnosis and led to definite treatment. Fragile bridging veins in the fluid-filled interdural layers were novelly verified as a bleeding source in SS. Recognizing this phenomenon is important since it can establish closure of the dural defect as a definite treatment in SS with an intraspinal cavity.

Endoscopic inter laminar management of lumbar disease

Discectomy for lumbar disc provides faster relief in acute attack than does conservative management. Long-term results of open, microscopy-, and endoscopy-assisted discectomy are same. Early results of endoscopy-assisted surgery are better as compared to that of open surgery in terms of better visualization, smaller incision, reduced hospital stay, better education, lower cost, less pain, early return to work, and rehabilitation. Although microscopic discectomy also has comparable advantages, endoscopic-assisted technique better addresses opposite side pathology. Inter laminar technique (ILT) and trans foraminal technique (TFT) are two main endoscopic approaches for lumbar pathologies. Endoscopy-assisted ILT can be performed in recurrent, migrated, and calcified discs. All lumbar levels including L5-S1 level, intracanalicular, foraminal disc, lumbar canal and lateral recess stenosis, multiple levels, and bilateral lesions can be managed by ILT. Migrated, calcified discs, L5-S1 pathology, lumbar canal, and lateral recess stenosis can be better approached by ILT than by TFT. Most spinal surgeons are familiar with anatomy of ILT. It can be safely performed in foramen stenosis and in uncooperative and anxious patients. There is less risk of exiting nerve root damage, especially in short pedicles and in presence of facet osteophytes as compared to TFT. On the other hand, ILT is more invasive than TFT with more chances of perforations of the dura matter, pseudomeningocele formation, and cerebrospinal fluid fistula in early learning curve. Obtaining microsurgical experience, attending workshops, and suitable patient selection can help shorten the learning curve. Once adequate skill is acquired, this procedure is safe and effective. The surgeon must be prepared to convert to an open procedure, especially in early learning curve. Spinal endoscopy is likely to achieve more roles in future. Endoscopy-assisted ILT is a safer alternative to the microscopic technique.

Subphrenic hematoma after thoracoscopic discectomy: description of a very rare adverse event and review of the literature on complications

The authors describe a very rare and previously unreported complication of thoracoscopic discectomy. Endoscopic spine surgery has evolved as a safe and effective treatment, and thoracoscopic discectomy, in particular, provides several advantages over open approaches, although it can be associated with intraoperative or postoperative complications. The most frequently observed adverse events are intercostal neuralgia, retained disc fragments, durotomies, atelectasis, extensive bleeding, and emergency conversion to open thoracotomy for vascular injuries. Even rare complications, such as chylorrhea or brain hemorrhagic infarction, have been reported. Nonetheless, a literature review did not reveal any case of postoperative intraabdominal hematoma following thoracoscopic discectomy. A 43-year-old woman, with no history of hematological or vascular disorders or thoracic surgery, underwent a right-sided thoracoscopic discectomy for T11–12 disc herniation. No apparent surgical technique–related complications were encountered, but intermittently repeated difficulties with single-lung ventilation occurred. The resultant dysventilation allowed partial right lung reexpansion, along with increased abdominal pressure. The latter induced an upward ballooning of the right diaphragm with consequent obstruction of the surgical field of view, requiring constant and continuous pressure applied to the thoracic surface of the diaphragm via a metal fan retractor and thus counteracting the increased abdominal pressure. Postoperatively, a large subdiaphragmatic hematoma originating from a bleeding right inferior phrenic artery was diagnosed and required urgent endovascular occlusion. The patient made an uneventful recovery with conservative treatment. A very rare and previously unreported complication—that is, early subdiaphragmatic hematoma after thoracoscopic discectomy—is described here. The authors submit that conversion to an open approach is safer when persistent anesthesia-related complications are encountered in thoracoscopic discectomy.

The incorporation of neuroendoscopy in neurosurgical training programs

Previously considered the domain of the otolaryngologists, the endoscopy is now a common part of the armamentarium of a neurosurgeon. Neuroendoscopy or endoscope-assisted microsurgery is now being used in almost all routine procedures performed in the neurosurgical operating room. Hands-on training has become essential to learn the basics of neuroendoscopy, even for neurosurgeons well accustomed to the use of microscopes. To decrease the slope of the learning curve of residents during their training and reduce complications of procedures, most neurosurgery training programs around the world have incorporated laboratory or dissection programs in their curricula. Preconference workshops held during annual meetings are also an excellent tool to aid in the transition of surgeons from being a resident under the umbrella of an attending neurosurgeon to being a neurosurgeon able to operate independently and with confidence. In this "tech-savvy era," various cadaver or synthetic models are readily available for endoscopy training in a virtually simulated environment. In accord with the results of a surveys conducted by individual groups and societies, the authors firmly believe that incorporation of endoscopy in the neurosurgical curriculum would add a new dimension to the existing protocol. There is an urgent need for dedicated endoscopy training programs similar to postresidency fellowships in addition to translational research and establishment of dedicated societies to formulate guidelines for such research and monitor its progress.

Piriformis syndrome after percutaneous endoscopic lumbar discectomy via the posterolateral approach

Percutaneous endoscopic lumbar discectomy (PELD) can be performed under local anesthesia with intravenous analgesics. To define the incidence of piriformis syndrome (PS) after PELD via the posterolateral approach under local anesthesia compared to that of general patients presenting with low back pain with/without lower leg pain. The incidence and time of occurrence of positive FAIR test after PELD within a 3-month follow-up period were evaluated retrospectively, and compared with the prevalence of general patients who visited the pain clinic for LBP with/without lower leg pain. Factors that may increase the incidence of PS after PELD were also evaluated. There was no patient with positive FAIR test immediately after PELD in the operation room and before walking. The prevalence of PS in general patients was 317/2,320 (13.7%); however, the incidence of PS after PELD within a 3-month follow-up period was 61/151 (40.4%), peaking at 32 days. High anxiety scale scores during operation led to increased incidence of PS after PELD. PELD under local anesthesia with high level of anxiety may increase the incidence of PS after walking, peaking around the first month, compared with the results for general patients with low back pain with/without lower leg pain.

Endoscopic minimally invasive neurosurgery: emerging techniques and expanding role through an extensive review of the literature and our own experience - part II: extraendoscopic neurosurgery

BACKGROUND/AIMS

The field of minimally invasive neurosurgery has grown dramatically especially in the last decades. This has been possible, in the most part, due to the advancements in technology especially in tools such as the endoscope. The contemporary classification scheme for endoscopic procedures needs to advance as well.

METHODS

The present classification scheme for neuroendoscopic procedures has become confusing because it mainly describes the use of the endoscope as an assisting device to the microscope. The authors propose an update to the current classification that reflects the independence of the endoscope as a tool in minimally invasive neurosurgery.

RESULTS

The proposed classification groups the procedures as 'intraendoscopic' neurosurgery or 'extraendoscopic' neurosurgery (XEN) in relation to the 'axis' of the endoscope. A review of the literature for the XEN group together with exemplary cases is presented.

CONCLUSION

We presented our proposed classification for the endoscope-only surgical procedures. The XEN group is expanded in this article.

[Minimally invasive spine arthrodesis in degenerative spinal disorders]

BACKGROUND AND PURPOSE

As in many other surgical fields, new minimally invasive techniques have been developed over the past 20 years, with reducing the muscular trauma associated with the traditional surgical approach and reducing related morbidity as the main goals. Initially limited to the laparoscopic or video-assisted approaches of the anterior spine, these techniques have been extended to the posterior transmuscular access of the lumbar spine. This article reviews the value of these approaches in the treatment of degenerative lumbar spine disorders.

METHODS

We describe the main techniques used in minimally invasive lumbar spine surgery, including posterior pedicle screwing as well as anterior (ALIF), posterior (PLIF), transforaminal (TLIF), extreme lateral (XLIf), and presacral (AxiaLIF) interbody fusion. The results of recently published series are reported.

RESULTS

Percutaneous pedicle screwing is reported to be an effective technique of lumbar spine arthrodesis associated with a low rate of screw misplacement. Minimally invasive PLIF, TLIF, and ALIF have been associated with shorter mean operative time, less postoperative pain, reduction of the estimated blood loss, a shorter hospital stay, and quicker functional recovery. Despite these encouraging early clinical results, no prospective, randomized published scientific study has proved that minimally invasive techniques are better than standard techniques. Larger clinical series with a longer follow-up could fill this gap.

History of endoscopic skull base surgery: its evolution and current reality

✓The history of the endoscope exemplifies the manner in which technological advances influence medicine and surgery. Endoscopic systems have evolved and improved, and they currently provide detailed visualization of a variety of deep organ structures. Otorhinolaryngological surgeons have used the endoscope for more than 30 years. In the 1990s, a number of influential neurosurgeons and otorhinolaryngological surgeons began performing purely endoscopic pituitary surgery. Endoscopic transsphenoidal operations are now extending beyond the sella. The collaboration between otorhinolaryngologists and neurosurgeons has produced a new subspecialty of “endoscopic skull base surgery.” There is a great deal of progress still to be made in developing skills, instruments, and improving skull base repair. The extended skull base approaches allow surgical exposures from the olfactory groove to C-2 and to the infratemporal region and jugular fossa laterally. This article discusses the history of the endoscope, the pivotal technological advances, and the key figures in the burgeoning field of endoneurosurgery.