Xinhua Hospital Performs World's First Trigeminal Motor Root-Abducens Nerve Transplantation

Background

Abducens nerve palsy occurs when the sixth cranial nerve is damaged, impairing the lateral rectus muscle responsible for moving the eye outward. This can lead to inward deviation of the eye, known as esotropia and colloquially referred to as crossed eyes, along with severe diplopia and changes in facial appearance. Traditional treatment approaches have primarily involved conservative measures such as medications and rehabilitation therapy, or corrective surgery on the eye muscles, which do not directly repair the damaged nerve.

What was achieved

In a case announced on February 14, 2025, the neurosurgery team led by Professor Li Shiting, director of neurosurgery at Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, completed the world's first trigeminal motor root-abducens nerve transplantation, also described as anastomosis. The patient, a 56-year-old woman referred to by the pseudonym Aunt Liu, had suffered a car accident in September 2024 resulting in bilateral abducens nerve palsy. Imaging using thin-slice abducens nerve MRI revealed complete rupture of the right abducens nerve and vascular compression at the root of the left abducens nerve.

During surgery on the right side, the proximal end of the ruptured nerve could not be located. The team therefore performed the novel procedure, anastomosing the motor root of the trigeminal nerve to the distal abducens nerve. One week later, they carried out microvascular decompression on the left side to relieve the vascular compression. According to reports, this innovation fills an international gap in the surgical treatment of abducens nerve injury, with no prior reports of the technique identified in the literature. Postoperatively, the patient's eye movement function recovered significantly, diplopia resolved, and her facial appearance returned to normal. She was discharged and has returned to normal life.

How it works

The abducens nerve (cranial nerve VI) exits the brainstem and travels a long intracranial course before innervating the lateral rectus muscle to abduct the eye. In traumatic cases like this one, the nerve can rupture or be compressed by blood vessels, disrupting signals to the muscle and causing the unopposed medial rectus to pull the eye inward. The innovative technique repurposes the motor root of the trigeminal nerve (cranial nerve V), which normally supplies motor innervation to the muscles of mastication.

In the procedure, under an operating microscope in the deep skull base where the working space is only a few millimeters, the surgical team meticulously anastomosed the trigeminal motor root to the distal portion of the abducens nerve, avoiding surrounding critical blood vessels and other neural structures. This reconstructs a functional pathway to reinnervate the lateral rectus muscle. For the contralateral side, microvascular decompression involved separating the compressing vessel from the abducens nerve root and placing padding material to prevent recurrent compression. The reports describe the surgery as requiring 'knife-tip dancing' precision to achieve high-accuracy suturing in this confined anatomy.

What it means for international patients

This case demonstrates specialized expertise in complex cranial nerve reconstruction and functional neurosurgery available at Xinhua Hospital. The hospital operates the Memorial Jinglang International Medical Center, which has been designated a pilot unit for Shanghai's international medical tourism program. It provides one-stop services for overseas patients, including multilingual support, visa assistance where applicable, and direct settlement with certain international commercial insurance providers. Patients from countries including the United States, Russia, India, Malaysia, Spain, France, and Australia have been treated there for various specialties.

International patients considering care for rare cranial nerve conditions or similar neurosurgical needs should contact the hospital's international department directly to determine eligibility, suitability for specific techniques, and current availability. Confirmation with the hospital is required for individual cases, as not all patients will meet criteria for such specialized interventions.

About the hospital

Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine is a tertiary Grade A public hospital located at 1665 Kongjiang Road in Shanghai's Yangpu District. Founded in 1958, it is recognized as one of China's leading pediatric centers with extensive subspecialties while also maintaining strong adult services across multiple disciplines. It houses 11 national key clinical specialties and serves as the Shanghai Quality Control Center for Rare Disease Diagnosis and Treatment.

The hospital's neurosurgery department, under Professor Li Shiting, has established expertise in cranial nerve disorders, including microvascular decompression techniques for conditions such as trigeminal neuralgia and hemifacial spasm, as well as innovative approaches to nerve repair and facial palsy. It operates the Memorial Jinglang International Medical Center, which holds DNV international accreditation and focuses on whole-life health services with dedicated support for international patients.