Diseases of the odontoid and craniovertebral junction with management by endoscopic approaches

Suture Repair in Endoscopic Surgery for Craniovertebral Junction

Objective

Endoscopic approaches to the craniovertebral junction (CVJ) have been established as viable and effective surgical treatments in the past decade. One of the major complications is leakage of the cerebrospinal fluid (CSF). This study aimed to investigate the efficacy and feasibility of suture closure at the nasopharyngeal mucosa upon durotomy.

Methods

A series of consecutive patients who underwent different endoscopic approaches to the CVJ were retrospectively reviewed. The pathologies, surgical corridors, neurological and functional outcomes, radiological evaluations, and complications were analyzed. Different strategies of repair for the intraoperative CSF leakage were described and compared.

Results

A total of 22 patients covering 13 years were analyzed. There were 12, 2, and 8 patients who underwent transnasal, transoral, and combined approaches, respectively. There were 8 patients (36.4%) who experienced intraoperative CSF leakage, and were grouped into 2: 4 in the nonsuture (NS) group and 4 in the suture-repaired (SR) group. The NS group had 3 (75%) persistent CSF leakages postoperation that caused 1 mortality, whereas patients of the SR group had only 1 minor CSF rhinorrhea that healed spontaneously within days.

Conclusion

In this series of 22 patients who required anterior endoscopic resection of pathologies at the CVJ, there was 1 (4.5%) serious complication related to CSF leakage. For patients who had no durotomy, the mucosal incision at the nasopharynx usually healed rapidly and there were few procedure-related complications. For patients with intraoperative CSF leakage, suture closure was technically challenging but could significantly lower the risks of postoperative complications.

Endoscopic transnasal anterior release and posterior reduction without odontoidectomy for irreducible atlantoaxial dislocation

Background

To investigate the efficacy and safety of endoscopic transnasal anterior release and posterior reduction without odontoidectomy to treat irreducible atlantoaxial dislocation (IAAD).

Methods

A series of 9 patients with IAAD underwent endoscopic transnasal anterior release and posterior reduction without odontoidectomy. Etiology, instrumentation, fusion rate, and complications were documented. All patients were assessed clinically and radiologically for neurological recovery using the Japanese Orthopedic Association (JOA) score, atlantodontoid interval (ADI), and cervicomedullary angle (CMA).

Results

The mean age of the patients was 41.6 years, ranging from 14 to 60 years. Pathology showed os odontoideum in 3 patients, old traumatic dens fracture in 3 patients, occipitalization of C1 in 2 patients, and rheumatoid arthritis in 1 patient. Seven patients underwent C1–C2 pedicle screw fixations, and 2 patients required occipitocervical fixation. Eight cases resulted in complete reduction and 1 in partial reduction. Complications included one superficial infection related to the posterior approach. All patients were followed up for an average of 17 (range 13–32) months. Bony fusion was confirmed in all cases under radiologic assessment at 1 year postoperatively, and the bony fusion rate reached 100%. Moreover, no instrumental failure occurred during the entire follow-up period. The JOA score improved from 7.21 ± 1.62 to 12.28 ± 0.81 at the last follow-up. The ADI of 9 cases was 7.06 ± 0.85 mm preoperatively, which decreased to 2.26 ± 0.56 mm at the final follow-up. CMA improved from 103.80° ± 4.16° to 143.23° ± 7.47° postoperatively.

Conclusion

With transnasal approach and lack of odontoidectomy, this method could not only treat IAAD safely and effectively, but also reduce the possibility of many complications associated with the traditional transoral approach and odontoidectomy.

Odontoid-sparing transnasal approach for drainage of craniocervical epidural abscess; a novel technique and review of the literature

BACKGROUND CONTEXT

Surgical approaches to the craniovertebral junction (CVJ) are challenging. Available approaches include posterior, transoral, endonasal, and anterior extended retropharyngeal approach. Resection of the odontoid process is necessary to gain access to the pathology posterior to it. The resultant cranio-atlanto-axial instability usually necessitates subsequent posterior stabilization.

PURPOSE

To describe a new odontoid-sparing approach to the spinal canal at the CVJ. This dens-sparing approach preserves occipito-atlanto-axial stability and avoids the need for occipitocervical stabilization that adds to the extent of surgery and its associated morbidity and mortality.

STUDY DESIGN

Describing a novel technique and reporting two cases.

PATIENT SAMPLE

Two patients that presented with infection at the CVJ with a retro-odontoid epidural abscess were operated on.

OUTCOME MEASURES

Self-reported measures: visual analog scale for neck pain. Physiologic measures: plain x-rays (anteroposterior and lateral views), magnetic resonance imaging with contrast, computed tomography scan, C-reactive protein, and leukocytic count. Functional measures: dynamic flexion-extension views of the cervical spine.

METHODS

Two patients were operated on using a combined endoscopic transnasal-transoral approach for drainage of a retro-odontoid epidural abscess and debridement without dens resection. A 4-mm, 30-degree rigid endoscope was used. Preoperative clinical and neurologic status was evaluated. The follow-up period was 12 months. The study received no funding from any organization. None of the authors has any relevant financial disclosures or conflict of interest.

RESULTS

Both patients improved clinically after the endonasal transoral abscess drainage. Follow-up contrast magnetic resonance imaging showed complete resolution of the abscess after 3 weeks. Culture-sensitivity tests were positive for Staphylococcus aureus in one patient. Antibiotic therapy with clindamycin and flucloxacillin was continued for 12 weeks postoperatively. There were no intraoperative or postoperative complications. There was no need for posterior occipitocervical stabilization in both cases.

CONCLUSION

This represents the first clinical report of accessing the spinal canal at the CVJ without resection of the odontoid or the anterior arch of the atlas. The addition of endoscopic-assisted supra-dental approach to the transoral one improved visibility, and allowed access to the most cranial part of spinal canal without the need for dens resection, a procedure that significantly compromises C0-1-2 stability necessitating stabilization. This novel odontoid-sparing approach showed a favorable outcome in our first two cases with retro-odontoid abscess; however, it would likely pose a high risk in other pathologies including tumors.

Endoscopic approach to the upper cervical spine and clivus: an anatomical study of the upper limits of the transoral corridor

BACKGROUND

Recent advances in endoscopic techniques have allowed minimally invasive approaches to the cranio-vertebral junction (CVJ) through the oropharynx (ETA) in addition to the transnasal approach (EEA). These minimally invasive endoscopic techniques allow for increased surgical exposure using no visible incisions, with a potential less morbidity. The ability to know preoperatively the limit of the ETA is vital for the surgical planning in order to better address CVJ pathology. The aim of the present study is to determine the anatomical limits of endoscopic dissection of the skull base and upper cervical spine through the transoral corridor and the superior limit reached by adopting this approach.

METHODS

Six fresh-frozen adult cadaver heads were dissected adopting ETA preserving the hard and soft palate. The most superior extent of the exposure was dissected. Post-operative CT scans were performed to confirm the superior extent.

RESULTS

The superior most limit of dissection corresponded to the sphenoid-occipital junction, where the basilar portion of the occipital bone joins with the sphenoid bone's body. This ranged from 12.7 to 18.9 mm above the line of the hard palate. This was achieved without having to transgress any of the palatine structures.

CONCLUSIONS

The sphenoid-occipital junction represents the rostral limit of endoscopic transoral approach to the lower skull base and CVJ area. This approach is limited superiorly by the orientation of the hard palate and mouth aperture and lower dentition due to the linear nature of the endoscope. Using the endoscope for this approach can allow for a more superior exposure than the traditional open transoral approach.

Endoscopic Transnasal Odontoidectomy

Transoral microscopic odontoidectomy followed by posterior fixation has been accepted as a standard procedure to treat nonreducible basilar invagination during the half past century. In recent years, the development of endoscopic techniques has raised challenges regarding the traditional treatment algorithm. The endoscopic transnasal odontoidectomy is a feasible and effective method in the treatment of irreducible ventral cervicomedullary junction compression, which has several advantages over the transoral approach. The endoscopic odontoidectomy includes transnasal, transoral, and transcervical approaches. The 3 different approaches for endoscopic odontoidectomy present complementary advantages and limitations. The necessity of posterior fixation after odontoidectomy should be considered in every single case on the basis of the peculiar anatomic and clinical conditions.

Endoscopic endonasal approach to the craniocervical junction: the importance of anterior C1 arch preservation or its reconstruction

We report our experience with the endoscopic endonasal approaches (EEA) for different craniocervical junction (CCJ) disorders to analyse outcomes and demonstrate the importance and feasibility of anterior C1 arch preservation or its reconstruction. Between January 2009 and December 2013, 10 patients underwent an endoscopic endonasal approach for different CCJ pathologies at our Institution. In 8 patients we were able to preserve the anterior C1 arch, while in 2 post-traumatic cases we reconstructed it. The CCJ disorders included 4 cases of irreducible anterior bulbo-medullary compression secondary to rheumatoid arthritis or CCJ anomalies, 4 cases of inveterate fractures of C1 and/or C2 and 2 tumours. Pre- and postoperative neuroradiological evaluation was always obtained by magnetic resonance imaging (MRI), computed tomographic (CT) scanning and dynamic cranio-vertebral junction x-ray. Pre- and postoperative neurologic disability assessment was obtained by Ranawat classification for patients with rheumatoid arthritis and by Nurick classification for the others. At a mean follow-up of 31 months (range: 14-73 months), an improvement of at least one Ranawat or Nurick classification level was observed in 6 patients, while in another 4 patients neurological conditions were stable. Radiological follow-up revealed an adequate bulbo-medullary decompression in all patients and a regular bone fusion in cases of C1 and/or C2 fractures. In all patients spinal stability was preserved and none required subsequent posterior fixation. The endoscopic endonasal surgery provided adequate exposure and a low morbidity minimally invasive approach to the antero-medial located lesions of the CCJ, resulting in a safe, effective and well-tolerated procedure. This approach allowed preservation of the anterior C1 arch and the avoidance of a posterior fixation in all patients of this series, thus preserving the rotational movement at C0-C2 segment and reducing the risk of a subaxial instability development.

The rhinopalatine line as a reliable predictor of the inferior extent of endonasal odontoidectomies

OBJECT

The endoscopic endonasal approach (EEA) provides a minimally invasive corridor through which the cervicomedullary junction can be decompressed with reduced morbidity rates compared to those with the classic transoral approaches. The limit of the EEA is its inferior extent, and preoperative estimation of its reach is vital for determining its suitability. The aim of this study was to evaluate the actual inferior limit of the EEA in a surgical series of patients and develop an accurate and reliable predictor that can be used in planning endonasal odontoidectomies.

METHODS

The actual inferior extent of surgery was determined in a series of 6 patients with adequate preoperative and postoperative imaging who underwent endoscopie endonasal odontoidectomy. The medians of the differences between several previously described predictive lines, namely the nasopalatine line (NPL) and nasoaxial line (NAxL), were compared with the actual surgical limit and the hard-palate line by using nonparametric statistics. A novel line, called the rhinopalatine line (RPL), was established and corresponded best with the actual limit of the surgery.

RESULTS

There were 4 adult and 2 pediatric patients included in this study. The NPL overestimated the inferior extent of the surgery by an average (± SD) of 21.9 ± 8.1 mm (range 14.7-32.5 mm). The NAxL and RPL overestimated the inferior limit of surgery by averages of 6.9 ± 3.8 mm (range 3.7-13.3 mm) and 1.7 ± 3.7 mm (range -2.8 to 8.3 mm), respectively. The medians of the differences between the NPL and NAxL and the actual surgery were statistically different (both p = 0.0313). In contrast, there was no statistically significant difference between the RPL and the inferior limit of surgery (p = 0.4375).

CONCLUSIONS

The RPL predicted the inferior limit of the EEA to the craniovertebral junction more accurately than previously described lines. The use of the RPL may help surgeons in choosing suitable candidates for the EEA and in selecting those for whom surgery through the oropharynx or the facial bones is the better approach.

Endoscopic Endonasal Odontoidectomy

Odontoidectomy is the treatment of choice for irreducible ventral cervical-medullary compression. The endonasal endoscopic approach is an innovative approach for odontoidectomy. The aim of this article is to identify in which conditions this approach is indicated, discussing variants of the technique for selected cases of craniovertebral malformation with platybasia. We believe that the technical difficulties of this approach are balanced by the advantages for patients. Some conditions related to the patient and to the anatomy of the craniovertebral junction may favor adoption of the endoscopic endonasal approach, which should be considered complementary and not alternative to standard approaches.

Endoscopic endonasal odontoidectomy: clinical series

STUDY DESIGN

This study evaluates a series of consecutive endoscopic endonasal odontoidectomies performed since 2008 in our center.

OBJECTIVE

The aim of the study was to analyze the outcome and the surgical technique to enlighten advantages and limitations of this procedure.

SUMMARY OF BACKGROUND DATA

Odontoidectomy represents the treatment of choice in selected cases of basilar invagination. Transoral-transpharyngeal odontoidectomy is the "gold standard" and more experienced technique. Recently, the endoscopic endonasal approach has been proposed as an alternative route.

METHODS

All patients underwent a pre- and postoperative evaluation of neurological status using physical neurological examination, assessment of American Spinal Injury Association impairment scale score, and neurophysiological investigations. Pre- and postoperative neuroradiological examinations consisted of magnetic resonance imaging, computed tomography, and radiography in flexion and extension. Surgical complications, time of orotracheal extubation and of resumption of oral feeding after surgery were considered, basing on medical records.

RESULTS

The series is composed of 5 cases. All cases presented a progressive tetraparesis despite a posterior occipitocervical arthrodesis. Two patients presented with irreducible atlantoaxial subluxation in Down syndrome, whereas the others presented with an atlanto-occipital malformation with platybasia and basilar invagination. No complications were observed. In all except one case, orotracheal intubation was removed immediately at the end of surgery. Oral feeding was resumed 1 day after surgery in all but one case that initially required an orogastric tube. At follow-up (mean: 34.2 mo; range: 3-57 mo), neurological symptoms have been shown to improve in 2 cases and stabilization, arresting the neurological worsening, in 3 cases.

CONCLUSION

Endoscopic endonasal odontoidectomy resulted in a safe, effective, and well-tolerated procedure. From our experience, we conclude that the different approaches for odontoidectomy should be considered to be complementary rather than alternative: the endonasal endoscopic can be advantageous in selected cases presenting some anatomical conditions related (micrognathia and macroglossia) to the oral cavity and to high position of the odontoid.

Endoscopic transnasal odontoidectomy combined with posterior reduction to treat basilar invagination: technical note

OBJECT

Transoral microscopic odontoidectomy has been accepted as a standard procedure to treat basilar invagination over the past several decades. In recent years the emergence of new technologies, including endoscopic odontoidectomy and posterior reduction, has presented a challenge to the traditional treatment algorithm. In this article, the authors describe 1 patient with basilar invagination who was successfully treated with endoscopic transnasal odontoidectomy combined with posterior reduction. The purpose of this report is to validate the effectiveness of this treatment algorithm in selected cases and describe several operative nuances and pearls based on the authors' experience.

METHODS

One patient with basilar invagination caused by a congenital osseous malformation underwent endoscopic transnasal odontoidectomy combined with posterior reduction in a single operative setting. The purely endoscopic transnasal odontoidectomy was first conducted with the patient supine. The favorable anatomical reduction was then achieved through a posterior approach after the patient was moved prone.

RESULTS

The patient was extubated after recovery from anesthesia and allowed oral food intake the next day. No complications were noted, and the patient was discharged 4 days after the operation. Postoperative imaging demonstrated excellent decompression of the anterior cervicomedullary junction pathology. The patient was followed up for 12 months and remarkable neurological recovery was observed.

CONCLUSIONS

The endoscopic transnasal odontoidectomy is a better minimally invasive approach for anterior decompression and can make the posterior reduction easier because the anterior resistant force is eliminated. The subsequent posterior reduction can make decompression of the ventral side of the cervicomedullary junction more effective because the C-2 vertebral body is pushed forward. A combination of these 2 approaches has the advantages of minimally invasive access and a faster patient recovery, and thus is a valid alternative in selected cases.

Evolution of Transoral Surgery

BACKGROUND:

Transoral surgery may be used to approach pathologies at the craniocervical junction. However, the need for this approach has decreased over the past few decades.

OBJECTIVE:

To assess the outcome and complications of transoral surgery and extended transoral approaches at a single UK center between 1980 and 2011.

METHODS:

A retrospective review was performed of 495 ventral midline operations (between1980 and 2004) and prospective review of 38 operations (2004-2011) in a total of 479 patients. Trends in surgery and factors associated with good or bad outcome were assessed over this 30-year period.

RESULTS:

Of 533 operations, the most frequently performed surgeries were simple transoral surgery (321 operations), transoral surgery with splitting of the palate (107 operations), open-door maxillotomy (58 operations), and mandibulotomy (11 operations). Since the 1990s, there has been a steady decrease in the number of operations performed, mainly due to the decrease in the number of patients with rheumatoid arthritis presenting for surgery. The incidence of craniocervical junction tumors remained constant. The number of complications was significantly associated with the preoperative neurological status, and more complications were seen in myelopathic rheumatoid patients as well as a greater trend in congenital basilar invagination. The rates of pharyngeal infection (0.6%) and cerebrospinal fluid leak (0.3%) for standard transoral surgery were extremely low.

CONCLUSION:

The number of transoral and associated operations has decreased over time. Transoral surgery is now mainly indicated for ventral midline tumors such as chordomas. Transnasal endoscopic techniques show promise, but a major advantage of standard transoral surgery is the low cerebrospinal fluid leak and infection rates.

Endoscopic transnasal odontoidectomy to treat basilar invagination with congenital osseous malformations

PURPOSE

Transoral resection of the odontoid has been accepted as a standard procedure to decompress the cervicomedullary junction during the past several decades. The endoscopic transnasal odontoidectomy is emerging as a feasible surgical alternative to conventional microscopic transoral approach. In this article, we describe several operative nuances and pearls from our experience about this approach, which provided successful decompression.

METHODS

From September 2009 to April 2010, three consecutive patients with basilar invagination, of which the etiology was congenital osseous malformations, underwent endoscopic transnasal odontoidectomy. All patients presented with myelopathy. The last two cases also received occipitocervical fixation and bone fusion during the same surgical episode to ensure stability.

RESULTS

All the patients were extubated after recovery from anesthesia and allowed oral food intake the next day. Cerebrospinal fluid rhinorrhea was found in the second case and cured by continuous lumber drainage of cerebrospinal fluid. No infection was noted. The average follow-up time was more than 24 months. Remarkable neurological recovery was observed postoperative in all patients.

CONCLUSION

The endoscopic transnasal odontoidectomy is a feasible approach for anterior decompression of pathology at the cervicomedullary junction. The advantages over the standard transoral odontoidectomy include elimination of risk of tongue swelling and teeth damaging, improvement of visualization, alleviation of prolonged intubation, reduction of need for enteral tube feeding and less risk of affecting phonation. The minimally invasive access and faster recovery associated with this technique make it a valid alternative for decompression of the ventral side of the cervicomedullary junction.