[Transoral approach in surgery for chordomas extending into craniovertebral junction: a systematic review of the literature]

To date, treatment of chordomas involves maximal tumor resection followed by proton therapy. Various approaches are used depending on location of tumor (transcranial and through natural anatomical openings (nose, mouth), as well as their combinations). Although transoral approach has been introduced into neurosurgical practice for a long time, it is routinely used in patients with chordoma only in certain hospitals in the world.

OBJECTIVE

To analyze postoperative outcomes in patients with chordomas of skull base and craniovertebral joint after transoral surgery.

MATERIAL AND METHODS

We analyzed literature data devoted to patients with chordomas of skull base and craniovertebral joint after transoral surgery or another approach combined with transoral access. Among 111 primary articles, we selected 38 manuscripts including description of 109 patients with skull base chordoma who underwent transoral surgery or combination of approaches including transoral one.

RESULTS

Gross total resection was achieved in 45.9% (n=50) of cases including 1 patient after en bloc resection. Subtotal resection was carried out in 28.4% of cases, partial - in 24.8%, biopsy - in 0.9% of cases. The complication rate in this group was 30%. The most common events were swelling of the tongue (10%) and diastasis of posterior pharyngeal wall sutures (8.2%) that required redo surgery. CSF leakage and meningitis were rare (1.8% and 3.6%, respectively).

CONCLUSION

Transoral access allows for gross total resection of midline tumors with low incidence of severe complications. Combination of transoral and transcranial approaches is advisable to increase extent of resection.

Time to Modify Rather than Discard the Transoral Approach to Selected Cases of Clival Chordomas at the Craniocervical Junction

Maintaining the transoral approach in the armamentarium of surgical approaches to clival chordomas mainly as a complimentary procedure to endonasal endoscopic approach in selected cases is advantageous. Lateral extension of the disease is a limitation to both approaches and is addressed by transcranial approaches. Especially for extensive lesions the simultaneous combination of approaches is based upon the predicted blind spots for each approach and certain technical nuances need to be considered.

Progress in Excision Methods of Bone Materials

Bone resection is a common technique in modern surgery, which can be divided into contact (such as mechanical osteotomy and ultrasonic osteotomy) and non-contact (such as laser osteotomy). Irrespective of the excision method, it causes processing damage to natural bone material, thus affecting bone healing. To reduce the machining damage in bone resection, different machining variables (cutting fluid temperature, feed rate, rotational speed, and ultrasonic frequency) were considered to explore the selection of various cutting conditions. This paper reviews the excision of natural bone materials including mechanical osteotomy, laser osteotomy, and ultrasonic osteotomy, especially traditional drilling and ultrasonic cutting, which represent the traditional and prospective methods of bone excision technology, respectively. Finally, the differences between methods are emphasized and the future trends in osteotomy technology and condition control during osteotomy are analyzed.

Robotic-Assisted Tubular Transoral Parapharyngeal Approach to the Ventral Craniovertebral Junction

BACKGROUND

Transoral robotic surgery (TORS) has become a routine technique for treating benign and malignant lesions of the oropharynx with the advantage of reducing morbidity compared to open surgical techniques. However, TORS has not been used routinely for accessing lesions of the spine.

OBJECTIVE

To describe how TORS can be used to access spinal lesions.

METHODS

We describe our technique of accessing the parapharyngeal space using the robotic technique, and then dissecting the prevertebral muscles to expose the ventral craniovertebral junction. Tubular retraction with endoscopic visualization is then employed for surgical resection. We then report a case of a 14-yr-old competitive athlete who presented with an osseous lesion of C1, which underwent resection using this novel TORS approach.

RESULTS

Our patient underwent successful resection of a lateral C1 osteoid osteoma utilizing a combined TORS/endoscopic approach. She tolerated soft diet immediately and was discharged on postoperative day 2. Postoperative imaging revealed complete resection of the lesion, and she returned to competitive athletics within 6 wk.

CONCLUSION

Utilizing this novel, robotic-assisted approach can definitively treat osseous cervical spine lesions while reducing morbidity, allowing for early return to normal diet and minimizing overall length of hospital stay.

Robotic transmaxillary approach to the lateral infratemporal fossa: A preclinical cadaveric study using a next-generation single-port robotic system

Robotic transmaxillary skull base surgery has been described using multiport systems. This cadaveric study investigates the feasibility of transmaxillary skull base surgery using a next-generation robot. An extended Caldwell-Luc antrostomy, measuring 3.3 cm by 4.0 cm, was performed in 15 min using a Kerrison rongeur and the robotic endoscope. A single-port, robotic system (da Vinci Sp®, Intuitive Surgical, Inc, Sunnyvale, CA, USA) was then deployed throught the extended Caldwell-Luc approach and provided sufficient reach, visualization, and maneuverability to work within the pterygopalatine fossa (PPF) and the infratemporal fossa (ITF) using three surgical instruments. The ITF dissection was easiest with two instruments using the third instrument to retract the muscles of mastication. This study demonstrates the feasibility of single-port robotic transmaxillary approaches to the lateral ITF. Using a single-port robotic system, the operating surgeon can for the first time work in the PPF and ITF using two functional arms for tumor dissection and a third to retract.