Endoscopic Transoral Excision of Odontoid Process in Irreducible Atlantoaxial Dislocation: Our Experience of 34 Patients

162

Original Article

Endoscopic Transoral Excision of Odontoid Process in Irreducible Atlantoaxial Dislocation: Our Experience of 34 Patients Yad Ram Yadav 1

Satya Narayan Madhariya 2

Vijay Singh Parihar 1

1 Department of Neurosurgery, NSCB Medical College and Hospital,

Jabalpur, Madhya Pradesh, India 2 Department of Neurosurgery, Ram Krishna Care Hospital, Raipur Chhattisgarh, India 3 Department of Radiodiagnosis, NSCB Medical College Jabalpur, Madhya Pradesh, India

Hehant Namdev 1

Pushp Raj Bhatele 3

Address for correspondence Yad Ram Yadav, Department of Neurosurgery, NSCB Medical College and Hospital, 105 Nehru Nagar, Opposite Medical College, Jabalpur, MP 482003, India (e-mail: [email protected]).

J Neurol Surg A 2013;74:162–167.

Abstract

Keywords

► ► ► ►

atlantoaxial joint dislocations atlantoaxial fusion endoscopic surgical procedures

received February 15, 2012 accepted after revision June 4, 2012 published online October 8, 2012

Background The endoscopic excision of the odontoid process in irreducible atlantoaxial dislocation (AAD) can be achieved by transnasal, transoral, and transcervical approaches. Endoscopic transoral technique has been found to be effective and safe. It avoids palatal splitting or prolonged retraction. We are reporting our experience of 34 cases. The relevant literature is reviewed. Material and Methods This was a prospective study of 34 patients treated during the past 5 years. Detailed history was taken and a thorough physical examination was made to record preoperative status. X-ray cervical spine lateral view (in neutral, flexion, and extension), anteroposterior (AP), and transoral view for the odontoid process were taken. Preoperative computed tomography (CT) and magnetic resonance imaging (MRI) scans and postoperative CT scans were done in all cases. Postoperative status at 1, 6, and 12 months was recorded. Results Age ranged from 15 to 56 years. There were 22 male and 12 female patients. Symptom duration ranged from 6 to 18 months.Preoperatively, there were 26 and 8 patients in Ranawat grades 3A and 3B, respectively. Five patients had tenth cranial nerve paresis. There were 23, 10, and 1 cases of AAD, AAD with basilar invasion, and tuberculosis, respectively. Palatal splitting was not required in any of the cases. All patients improved after surgery. No deaths occurred. One patient had cerebrospinal fluid (CSF) leak, which stopped after external lumbar drainage. Follow-up ranged from 12 to 65 months. Conclusion Endoscopic transoral odontoidectomy is a safe and effective alternative technique for odontoid excision. It can be performed in patients with small oral openings. Angled scopes improved exposure of clivus and palatal splitting was not required even in basilar invasion.

© 2013 Georg Thieme Verlag KG Stuttgart · New York

DOI http://dx.doi.org/ 10.1055/s-0032-1327441. ISSN 2193-6315.

Excision of Odontoid Process in Atlantoaxial Dislocation

Yadav et al.

Figure 1 Preoperative magnetic resonance imaging scans of case 1 showing atlantoaxial dislocation with basilar invasion. Odontoid process is producing compression on the cord.

Introduction There are increasing reports of endoscopic approaches being used for neurosurgical conditions.1–4 Although the most common surgical approach for irreducible atlantoaxial dislocation (AAD) with or without basilar invasion is transoral microscopic resection,5 recently endoscopic endonasal6–17 and endoscopic transoral18–24 approaches have been proposed. The minimally invasive technique of endoscopic transoral excision of the odontoid has been found to be most direct, effective, and safe.18–24 We are reporting our initial experience of endoscopic odontoidectomy of 34 cases. The relevant literature is reviewed.

Material and Methods This was a prospective study of 34 patients treated from July 2006 to November 2010. Detailed history was taken and a thorough physical examination was performed to record the preoperative status. The Ranawat scale25 was used for clinical assessment of patients. Grade 1 patients had pain without neurological deficit, grade 2 patients subjective weakness, hyper-reflexia, or dysesthesia. Grade 3A patients had a neurological deficit, but were ambulatory whereas Grade 3B patients had a neurological deficit and were were nonambulatory. X-ray of the craniovertebral region (lateral view [in neutral, flexion, and extension], anteroposterior [AP], and transoral view for odontoid process) were taken. Preoperative computed tomography (CT) and magnetic resonance imaging (MRI) scans were done in all cases (►Fig. 1). Preoperative skeletal traction was applied in all cases. If the dislocation did not reduce after traction, the AAD was defined as irreducible. Most cases of AAD can be reduced by preoperative traction. Postoperative CT scans were done in all cases (►Fig. 2). MRI was done when steel implants were not used. All postoperative complications were recorded. Special attention was paid to respiratory function in the postoperative period. Postoperative status at 1, 6, and 12 months was recorded. Follow-up ranged from 12 to 65 months.

Procedure Neck was positioned in slight extension in most of our patients, although neutral position can be used. The tongue was retracted by a Dingman retractor. A 4-mm endoscope was used. A 0-degree endoscope was positioned in the centre while a

30-degree scope was placed in the corner of the operative field. We found that the 30-cm endoscope was better than the 18-cm endoscope. Camera and light source cable are kept away from the instruments used in surgery. The uvula was retracted into the nasopharynx with the help of infant feeding tube passed through the nose. The uvula was fixed to the end of infant feeding tube by a suture and was pulled gently in the nasal cavity. This helped in increasing the cranial exposure. The posterior pharyngeal wall was infiltrated with lidocaine and adrenaline. A midline incision was made in the posterior pharyngeal wall. The pharyngeal wall was retracted using a pharyngeal retractor. The upper border of odontoid process and the intervertebral disc between C2 and C3 were identified using fluoroscopy. All the instruments were passed by the side of endoscope. Odontoidectomy was done after resecting the anterior arch of atlas in the same way as in microsurgical technique (►Fig. 3). The amount of excision of the C2 base was decided by preoperative MRI. Palatal splitting or self-retracting retractors for the soft palate was not required in any case. The palate could be further pushed upwards by suction or any other micro-instrument used in dissection. Posterior fixation was done in the same narcosis after careful turning of the patient on traction in most of the cases. Oral feeding was started on postoperative day 5.

Results This was a prospective study of 34 patients. Ages ranged from 15 to 56 years (►Table 1). There were 22 male and 12 female patients. Symptom duration ranged from 6 to 18 months. All patients had quadriparesis. Mouth opening was only 1.5 cm in one patient due to chronic tobacco chewing. Preoperatively, there were 26 and 8 patients in Ranawat grade 3A and 3B, respectively. Five patients also had tenth cranial nerve paresis. There were 23 cases of AAD, 10 of basilar invasion, and 1 of tuberculosis. All patients improved after surgery. There were 28 and 6 patients in Ranawat grade 1 and 2, respectively, at 1-year follow-up. Out of the 26 patients of Ranawat grade 3A before surgery, 23 and 3 cases improved to Ranawat grade 1and 2, respectively, after surgery. Likewise 8 cases of preoperative Ranawat grade 3B improved to grade 1 and 2 in 5 and 3 cases, respectively, at 1-year follow-up. Part of the lower clivus was drilled in 5 cases. There was good exposure from lower Journal of Neurological Surgery—Part A

Vol. 74

No. A3/2013

163

164

Excision of Odontoid Process in Atlantoaxial Dislocation

Yadav et al.

Figure 2 Postoperative coronal (upper line) and sagittal (lower line) computed tomography scans of case 1 showing good excision of the odontoid process.

Figure 3 Endoscopic transoral technique showing (a) infiltration of lidocaine and adrenaline in the posterior pharyngeal wall, (b) hemostasis of the cut margins of the pharynx, (c) coagulations using insulated monopolar forceps, (d, e, f, g, h) drilling of anterior arch of atlas and odontoid process and (i) suturing of posterior pharyngeal. Journal of Neurological Surgery—Part A

Vol. 74

No. A3/2013

Excision of Odontoid Process in Atlantoaxial Dislocation

Yadav et al.

Table 1 Patient Demography, Complications of Procedure, Advantages and Disadvantages of Endoscopic TransOral Odontoidectomy Age

Ages ranged from 15 to 56 years

Sex

22 male and 12 female patients

Symptoms duration

Symptom duration ranged from 6 to 18 months

Pathology

There were 23, 10, and 1 cases of AAD, basilar invasion, and tuberculosis, respectively Mouth opening was 1.5 cm in one patient

Preoperative clinical grades

There were 26 and 8 patients in 3A and 3B Ranawat scale, respectively

Procedure

Part of the lower clivus was drilled in 5 cases Good exposure from lower clivus to C2–3 disc space could be achieved in all cases Posterior fixation was done in the same operative procedure in 29 cases

Postoperative clinical grade

There were 28 and 6 patients in Ranawat grade 1 and 2, respectively, at 1 year follow-up

Advantage

Endoscopic transoral excision of the odontoid process is most direct approach, which is effective and safe Palatal spiting or prolonged retraction can be avoided; it can be done when oral opening is as small as 1.5 cm Surgery can be done in any neck position (flexion or extension); it gives good exposure from lower clivus to C2–3 disc space

Disadvantage

The risk of contamination by bacterial flora Difficulties in closing dura mater Difficulties in early postoperative oral feeding Patients with severe trismus (inability to distract the jaw open) could pose difficulties

Complications

There was no death One patient had cerebrospinal fluid leak, which stopped after external lumbar drainage

clivus to C2–3 disc space in all cases. Good decompression with complete odontoidectomy and resection of the C2 base could be achieved in all the cases. Posterior fixation was done in the same narcosis in 29 cases. Stainless steel contoured rod implant was used due to financial constrains in 26 cases, whereas in 8 cases titanium implants were used for posterior fixation. Routine extubation immediately after surgery was done in 33 patients; the tube was left in place for 24 hours in one case of difficult intubation. There were no deaths. One patient had a cerebrospinal fluid (CSF) leak, which stopped after external lumbar drainage. Most of the patients continued to experience some swallowing difficulties for up to 2 to 3 weeks.

Discussion The surgical approaches available for irreducible AAD with or without basilar invasion are the transoral microscopic resection, endoscopic transnasal excision, and endoscopic transoral excision. There are also reports of transcervical excision of the odontoid process,26–28 anterior release and anterior fusion,2,22,23,29,30 anterior release and posterior fusion,27,28 and posterior approach with reduction and fusion.31,32 Endoscopic transoral excision of the odontoid process was found to be direct, effective, and safe in our study. Good decompression with complete odontoidectomy and resection of the C2 base and the lower part of the clivus could be achieved in all the cases in our study. Pillai et al18 also reported better surgical exposure in the region of the posterior pharyngeal wall and clivus by the endoscopic technique as compared to the microsurgical technique. Mazhar Husain

et al19 also were able to achieve good decompression in all patients. Palatal splitting, usually required in the microsurgical technique especially in basilar invasion, could be avoided in all our patients. Similar results were reported earlier.18–24 This procedure could be done when the mouth opening was 1.5 cm; at least a 2.5 to 3 cm opening is required in microscopic excision. Surgery could be performed in any neck position (flexion or extension). On the other hand, this technique is associated with difficulties in closing the dura mater and postoperative swallowing difficulties. We encountered one case of CSF leak. Most of the patients in our series continued to experience some swallowing difficulties for up to 2 to 3 weeks. We did not observe an infection, though there was a risk of contamination by oral bacterial flora. The endoscopic transnasal approach to the ventral craniovertebral junction is also safe and effective.6,7,15–17 It has the advantages of early oral feeding without palatal splitting or tongue edema. This could be done in patients with less than a 2.5 cm mouth opening, head immobilized or in a halo jacket, and in any neck position (flexion or extension). There is theoretically a reduced risk of infection. It also has its own limitations, especially difficulties in excision of the lower body of C2.9,33 The transoral microscopic technique5 and endonasal,34 endoscopic, transoral,34 and transcervical approaches26–34 for odontoid exposure have their own limitations. Combined transoral and transnasal approaches could be used for decompression of lesions located high above the level of the palate and extending below the lower part of C2.35,36 Video-assisted anterior transcervical single-stage anterior release, reduction, and posterior fixation was found Journal of Neurological Surgery—Part A

Vol. 74

No. A3/2013

165

166

Excision of Odontoid Process in Atlantoaxial Dislocation to be safe and effective.27,28 An artificial atlanto-odontoid joint can be implanted, which could provide stability and preserve rotation after odontoid resection.37 A single-stage procedure employing transoral atlantoaxial reduction plate for fixed AAD can avoid the need for resection of dens and clivus and/or a posterior instrumentation and fusion procedure. We attempted routine extubation immediately after surgery unless there was a concern about a difficult airway. Adequate preoperative evaluation of the airway and choosing the appropriate intubation technique, including awake intubation, is very important to prevent injury to the cord, especially in unstable spine.38 An endotracheal tube can be left for some days postoperatively, especially in difficult airway and patients with significant tongue and pharyngeal edema. Special attention should be paid to respiratory function in the postoperative period.39 It was observed that the deterioration of pulmonary function (forced vital capacity, forced expiratory ratio, and forced expiratory flow) in the AAD group was significantly greater as compared with patients undergoing surgery for compressive cervical lesions or craniotomy for a cerebral lesion.

Yadav et al.

8

9

10

11

12

13

14

Conclusion Endoscopic transoral odontoidectomy is an alternative minimally invasive technique that is safe and effective. It can be performed in patients with a small mouth opening. An angled endoscope improves exposure of the clivus. Palatal splitting is not required even in basilar invasion.

15

16

17

Conflict of Interest None

18

References 1 Yadav YR, Parihar V, Agarwal M, Sherekar S, Bhatele P. Endoscopic

2

3

4

5

6

7

vascular decompression of the trigeminal nerve. Minim Invasive Neurosurg 2011;54:110–114 Ai FZ, Yin QS, Xu DC, Xia H, Wu ZH, Mai XH. Transoral atlantoaxial reduction plate internal fixation with transoral transpedicular or articular mass screw of C2 for the treatment of irreducible atlantoaxial dislocation: two case reports. Spine (Phila Pa 1976) 2011;36:E556–E562 Yadav YR, Yadav S, Sherekar S, Parihar V. A new minimally invasive tubular brain retractor system for surgery of deep intracerebral hematoma. Neurol India 2011;59:74–77 Yadav YR, Shenoy R, Mukerji G, Parihar V. Water jet dissection technique for endoscopic third ventriculostomy minimises the risk of bleeding and neurological complications in obstructive hydrocephalus with a thick and opaque third ventricle floor. Minim Invasive Neurosurg 2010;53:155–158 Liu JK, Couldwell WT, Apfelbaum RI. Transoral approach and extended modifications for lesions of the ventral foramen magnum and craniovertebral junction. Skull Base 2008;18:151–166 Messina A, Bruno MC, Decq P, et al. Pure endoscopic endonasal odontoidectomy: anatomical study. Neurosurg Rev 2007;30: 189–194, discussion 194 Leng LZ, Anand VK, Hartl R, Schwartz TH. Endonasal endoscopic resection of an os odontoideum to decompress the cervicomedul-

Journal of Neurological Surgery—Part A

Vol. 74

No. A3/2013

19

20

21 22

23

24

25

lary junction: a minimal access surgical technique. Spine (Phila Pa 1976) 2009;34:E139–E143 Kassam AB, Snyderman C, Gardner P, Carrau R, Spiro R. The expanded endonasal approach: a fully endoscopic transnasal approach and resection of the odontoid process: technical case report. Neurosurgery 2005;57(1, Suppl):E213, discussion E213 Nayak JV, Gardner PA, Vescan AD, Carrau RL, Kassam AB, Snyderman CH. Experience with the expanded endonasal approach for resection of the odontoid process in rheumatoid disease. Am J Rhinol 2007;21:601–606 Laufer I, Greenfield JP, Anand VK, et al. Endonasal endoscopic resection of the odontoid in a non-achondroplastic dwarf with juvenile rheumatoid arthritis, feasibility of the approach and utility of intraoperative iso-C 3D navigation. J Neurosurg Spine 2008;8:376–380 Abuzayed B, Tanriöver N, Gazioğlu N, Ozlen F, Eraslan BS, Akar Z. Extended endoscopic endonasal approach to the anterior craniovertebral junction: anatomic study. Turk Neurosurg 2009;19: 249–255 Alfieri A, Jho HD, Tschabitscher M. Endoscopic endonasal approach to the ventral cranio-cervical junction: anatomical study. Acta Neurochir (Wien) 2002;144:219–225, discussion 225 Magrini S, Pasquini E, Mazzatenta D, Mascari C, Galassi E, Frank G. Endoscopic endonasal odontoidectomy in a patient affected by Down syndrome: technical case report. Neurosurgery 2008;63: E373–E374, discussion E374 Wu JC, Huang WC, Cheng H, et al. Endoscopic transnasal transclival odontoidectomy: a new approach to decompression: technical case report. Neurosurgery 2008;63(1, Suppl 1):ONSE92-4, discussion E94 Gempt J, Lehmberg J, Meyer B, Stoffel M. Endoscopic transnasal resection of the odontoid in a patient with severe brainstem compression. Acta Neurochir (Wien) 2010;152:559–560 Cornelius JF, Kania R, Bostelmann R, Herman P, George B. Transnasal endoscopic odontoidectomy after occipito-cervical fusion during the same operative setting—technical note. Neurosurg Rev 2011;34:115–121 Puraviappan P, Tang IP, Yong DJ, Prepageran N, Carrau RL, Kassam AB. Endoscopic, endonasal decompression of spinal stenosis with myelopathy secondary to cranio-vertebral tuberculosis: two cases. J Laryngol Otol 2010;124:816–819 Pillai P, Baig MN, Karas CS, Ammirati M. Endoscopic image-guided transoral approach to the craniovertebral junction: an anatomic study comparing surgical exposure and surgical freedom obtained with the endoscope and the operating microscope. Neurosurgery 2009;64(5, Suppl 2):437–442, discussion 442–444 Husain M, Rastogi M, Ojha BK, Chandra A, Jha DK. Endoscopic transoral surgery for craniovertebral junction anomalies. Technical note. J Neurosurg Spine 2006;5:367–373 Frempong-Boadu AK, Faunce WA, Fessler RG. Endoscopically assisted transoral-transpharyngeal approach to the craniovertebral junction. Neurosurgery 2002;51(5, Suppl):S60–S66Comment in: Neurosurgery. 2003; 52:1511–2 Lee SC, Senior BA. Endoscopic skull base surgery. Clin Exp Otorhinolaryngol 2008;1:53–62 Wu YS, Chi YL, Wang XY, et al. Microendoscopic anterior approach for irreducible atlantoaxial dislocation: surgical techniques and preliminary results. J Spinal Disord Tech 2010;23:113–120 Chi YL, Xu HZ, Lin Y, et al. [Percutaneous microendoscopic anterior release, fixation and fusion for irreducible atlanto-axial dislocation]. Zhonghua Wai Ke Za Zhi 2007;45:383–386 Yadav YR, Shenoy R, Mukerji G, Sherekar S, Parihar V. Endoscopic transoral excision of odontoid process in irreducible atlanto-axial dislocation. In: Banerji APD, ed. Progress in Clinical Neurosciences. 24. Byword Books Private Limited; 2010 Ranawat CS, O’Leary P, Pellicci P, Tsairis P, Marchisello P, Dorr L. Cervical fusion in rheumatoid arthritis. J Bone Joint Surg Am 1979; 61:1003–1010

Excision of Odontoid Process in Atlantoaxial Dislocation

Yadav et al.

26 Wolinsky JP, Sciubba DM, Suk I, Gokaslan ZL. Endoscopic image-

33 de Almeida JR, Zanation AM, Snyderman CH, et al. Defining the

guided odontoidectomy for decompression of basilar invagination via a standard anterior cervical approach. Technical note. J Neurosurg Spine 2007;6:184–191 Liu T, Li F, Xiong W, et al. Video-assisted anterior transcervical approach for the reduction of irreducible atlantoaxial dislocation. Spine (Phila Pa 1976) 2010;35:1495–1501 Lü G, Passias PG, Li G, et al. Endoscopically assisted anterior release and reduction through anterolateral retropharyngeal approach for fixed atlantoaxial dislocation. Spine (Phila Pa 1976) 2010;35: 544–551 Li WL, Chi YL, Xu HZ, et al. Percutaneous anterior transarticular screw fixation for atlantoaxial instability: a case series. J Bone Joint Surg Br 2010;92:545–549 Wang X, Fan CY, Liu ZH. The single transoral approach for os odontoideum with irreducible atlantoaxial dislocation. Eur Spine J 2010;19(Suppl 2):S91–S95 Goel A, Kulkarni AG, Sharma P. Reduction of fixed atlantoaxial dislocation in 24 cases: technical note. J Neurosurg Spine 2005; 2:505–509 Visocchi M, Pietrini D, Tufo T, Fernandez E, Di Rocco C. Preoperative irreducible C1-C2 dislocations: intra-operative reduction and posterior fixation. The “always posterior strategy”. Acta Neurochir (Wien) 2009;151:551–559, discussion 560

nasopalatine line: the limit for endonasal surgery of the spine. Laryngoscope 2009;119:239–244 Baird CJ, Conway JE, Sciubba DM, Prevedello DM, QuiñonesHinojosa A, Kassam AB. Radiographic and anatomic basis of endoscopic anterior craniocervical decompression: a comparison of endonasal, transoral, and transcervical approaches. Neurosurgery 2009;65(6, Suppl):158–163, discussion 63–64 El-Sayed IH, Wu JC, Ames CP, Balamurali G, Mummaneni PV. Combined transnasal and transoral endoscopic approaches to the craniovertebral junction. J Craniovertebr Junction Spine 2010;1:44–48 Yin Tsang RK, Ho WK, Wei WI. Combined transnasal endoscopic and transoral robotic resection of recurrent nasopharyngeal carcinoma. Head Neck 2011; Epub ahead of print Lu B, He XJ, Zhao CG, Li HP, Wang D. Artificial atlanto-odontoid joint replacement through a transoral approach. Eur Spine J 2009;18:109–117 Sener EB, Sarihasan B, Ustun E, Kocamanoglu S, Kelsaka E, Tur A. Awake tracheal intubation through the intubating laryngeal mask airway in a patient with halo traction. Can J Anaesth 2002;49: 610–613 Reddy KR, Rao GS, Devi BI, Prasad PV, Ramesh VJ. Pulmonary function after surgery for congenital atlantoaxial dislocation: a comparison with surgery for compressive cervical myelopathy and craniotomy. J Neurosurg Anesthesiol 2009;21:196–201

27

28

29

30

31

32

34

35

36

37

38

39

Journal of Neurological Surgery—Part A

Vol. 74

No. A3/2013

167