MacF : Microsurgical Anterior Cervical Foraminotomy
The cervical spine contains the spinal cord, and 8 pairs of cervical nerve roots which control the movement and sensation of both arms and hands. Symptoms, such as pain, numbness, and tingling of shoulders, arms, and hands, are induced by compression of misplaced cartilage (disc herniation), and bone spurs on nerve roots. To remove compression (decompression) on nerve roots, surgeons excise cartilage and bone spurs from the front of the cervical spine under a microscope to improve blood circulation, and repair damaged function of the nerve root to improve symptoms.
A transverse cut approximately 25-35 mm in length is made in the front of the neck along the skin fold. Neck muscles are retracted through the skin incision, and the front part of the cervical spine is examined to identify the lateral corner of disc space (Luschka joint). The area of the Luschka joint is excised by electric drill to expose the nerve root for decompression under the microscope (Key hole surgery). Misplaced cartilage, bone spurs, and ossified ligaments which compress the nerve root are thoroughly excised. Metallic implants are not used for stabilization. A drain tube is left in the wound and the skin is closed using DERMABOND®. A cervical brace is not applied. The operating time is approximately one to two hours. Introduction of anesthesia and post-anesthesia arousal time take approximately one additional hour, making the total operation time two to three hours.
Immediately after surgery, symptoms improve due to increased blood circulation to nerve roots. In some patients, edema or inflammation of the nerve root may occur as a result of acute decompression, and symptoms may stop improving between two days to one month after surgery. However, symptoms due to edema and inflammation subside in three to four months. Symptoms become permanent in less than 1% of patients. Improvement is much stronger in cases of nerve root damage than in spinal cord damage, and maximum symptom improvement occurs at six months post-surgery. Some patients, such as those who have long standing symptoms or severely damaged nerves, may not recover completely, leaving numbness, tingling, and weakness in the hands and arms. Long term significant weakness in the arms and hands may take one year or more to recover. In some patients, decompressed and enlarged nerve root canals may narrow or close after surgery. Approximately 1% of patients require a second operation.
1. Nerve damage and dural tear
During decompression of the nerve root in a narrow canal, nerve damage could occur. When symptoms worsen due to nerve damage, usually they flare up temporarily but subside within a few weeks in most patients. These symptoms become permanent in less than 1% of patients. In the case of a dural tear, the tear is repaired immediately using a sealing method.
2. Postoperative hematoma
Blood collection may occur in the space between the trachea (wind pipe), esophagus, and cervical spine after surgery acutely obstructing the trachea. This may occur in bed after the patient is transferred to their room. The airway should be kept open immediately by intubation or tracheostomy (cutting trachea to keep the airway open), and blood collection should be removed in the operating room. This is rare and, in my personal experience, has occurred in only 0.2% of 1000 cases.
3. Difficulty swallowing or hoarseness
Edema could occur along the esophagus and the patient may complain of difficulty swallowing or hoarseness a few days after surgery. In most cases, these symptoms disappear without special care. However, some hoarseness may be a result of traction damage of the recurrent laryngeal nerve in the throat. Patients may complain of difficulty with speech or deep breathing. Typically, this takes about six months to heal without special care.
4.Eyelid drooping (Horner syndrome)or abnormal sweating (Dyshidrosis)
Eyelid drooping combined with an inset eye may appear immediately after surgery, or a few days post-surgery. Sympathetic nerves may be injured during the preparation of the surgical field due to the sympathetic nerves running along the carotid artery and cervical spine. Approximately 1% of patients may feel abnormal sweating on the same half of their body as the surgical site. Both complications typically clear up in a few months, but may persist for longer.
5. Injury to esophagus
Due to its proximity to the surgical field, the esophagus may be injured. In such a case, the injured section is repaired surgically.
6. Sensory loss in the jaw region
Numbness may occur on the skin of the jaw above the transverse skin incision as a result of injury to small skin sensory nerves while making the incision. This will heal a few months post-surgery.
7. Autonomic nerve disturbance
Dizziness, abnormal sweating, and palpitation, such as that seen in autonomic nerve disturbance, may occur after surgery and last for a few weeks, but will typically disappear. On the contrary, in patients who have symptoms of autonomic nerve disturbance before surgery, their symptoms may disappear or improve after surgery.
8. Disc degeneration at operated disc level
Progressive reduction of the operated disc hight is commonly seen due to disc degeneration, but scoliotic or kyphotic deformity is rarely seen after microsurgical anterior cervical foraminotomy.
9. Second operation on the Luschka joint on the opposite side
Pain, numbness, and tingling of the arms and hands may occur on the opposite side of surgery shortly after surgery. These radicular symptoms are thought to be provoked by increased narrowing of the nerve root canal induced by increased stress to the Luschka joint of the opposite side. In most such cases, conservative care can address these symptoms, but some patients may need a second MacF operation on the opposite side. This complication appears more commonly among patients whose preoperative diagnostic images show narrowing of the nerve canal.
10. Injury of vertebral artery (VAI)
Because the vertebral artery runs very close to the nerve root to be decompressed, injury can occur. But in my series of 1000 patients, the incidence of VAI was 0.2%. In all cases of VAI, this could be successfully controlled by applying a hemostatic agent together with pressure for 15 min. There have been no cases that were unable to be controlled in my personal experience.
The rate of surgical site infection in our institution has been approximately 1 %. Infection can occur in cervical surgery, particularly among elderly patients with decreased immune strength as a result of diabetes or poor renal function. Early surgical intervention is recommended in our institution to minimize risk of infection.
12. Delayed healing of surgical wound
Some patients may have allergic reactions to suture material and the wound may not heal properly. If this is the case, the surgical wound will be resutured.
13. Pulmonary embolism and deep vein thrombosis
Blood clots may appear in deep veins in the legs, travel into large veins in the abdomen, and finally reach the lungs, cutting off blood circulation to the lung. To prevent blood clot formation in the legs, patients should arise from the bed as early as possible wearing elastic stockings on the legs. I have not seen any of those complications in my series of 1000 patients.
14. Postoperative disorientation or dementia
This is common among elderly patients and appears temporarily immediately after surgery.
15. Medical complications
Many other complications, such as cardiac infarct, cerebral vascular accidents, or pulmonary embolisms, may occur during or after surgery and may be fatal in some elderly patients.