Abstract

The goal of surgical positioning is to provide optimal surgical access and visualization while maintaining the patient's safety, with the least physiological compromise. Here, we report a 30-year-old man with an unremarkable past medical history who developed superior vena cava syndrome after a 15-hour retrosigmoid craniotomy for removal of a right cerebellopontine (CP) angle tumor. Compartment syndrome from the head to neck and rhabdomyolysis were recognized, with extensive swelling of his head and neck, markedly swollen soft tissues and necrosis of multiple muscles revealed by computed tomography, and very high concentrations of creatine kinase (CK) and aspartate transaminase. Immediate intensive care and rehabilitation therapy were provided and aimed at maintaining adequate perfusion/oxygenation and decreasing tissue pressure. He was successfully weaned from ventilation on postoperative day (POD) 25, transferred to a general ward on POD 29, and discharged with mild muscular and neurological sequelae on POD 51. Careful adjustment of surgical positioning is crucial for patient safety, especially when positioned at an extreme position in association with prolonged surgery.

Keywords

Compartment syndromes; Cerebellopontine angle; Craniotomy: retrosigmoid approach; Rhabdomyolysis;

1. Introduction

Adjusting the surgical position is important to provide optimal surgical access for surgeons. However, an inappropriate position can result in complications, such as nerve injury, poor tissue perfusion, compartment syndrome, and cardiopulmonary embarrassment. Several instances of surgical positioning-related rhabdomyolysis and/or compartment syndrome have been associated with lithotomy,1, 2 lateral decubitus,3, 4 and hyperlordotic positions.⁵Inappropriate head/neck rotation and body positioning in patients who undergo cranial surgery may impede cerebral blood flow and venous drainage, and clinicians should prohibit extreme rotation of the patient's neck, minimize compression of the blood vessels, and protect the patients from secondary injury, especially for during long surgical procedures. We report here a case of postoperative compartment syndrome with rhabdomyolysis of the neck and head in a 30-year-old man, which was attributed to prolonged extreme rotation of the head and neck during retrosigmoid craniotomy.

2. Case report

A 30-year-old man, without significant medical history, was admitted to our hospital due to symptoms of tinnitus, hearing impairment, and motion sickness for 3 months. Laboratory tests and chest roentgenogram examination were unremarkable, except that a computerized tomogram of the brain demonstrated a tumor at the right cerebellopontine (CP) angle. He was scheduled for retrosigmoid craniotomy under general anesthesia for total removal of the CP angle tumor. General anesthesia was induced with 0.5 mg atropine, 5 mg/kg thiopental, 3 μg/kg fentanyl, and 1 mg/kg rocuronium, to facilitate nasotracheal intubation, and anesthesia was maintained with 1 vol% isoflurane in 60% oxygen/air mixture, rocuronium, and continuous infusion of fentanyl (3–5 μg/kg/hour). Ventilation was aimed to maintain the end-tidal CO₂ at around 28–35 mmHg. Besides the standard anesthetic monitoring, continuous arterial blood pressure and central venous pressure were monitored via the right radial artery and the left femoral vein, respectively. After ineffective communication about surgical positioning, the patient was placed in the supine position, with his head rotated almost 90 degrees to the left side and held with a Mayfield skeletal fixation head rest throughout the surgery (Fig. 1). To avoid tissue hypoperfusion and external compression of venous drainage, the mean arterial blood pressure was maintained around 65–75 mmHg and intermittent manual retraction of the left shoulder away from the head was applied throughout the surgery. The surgery lasted for 15 hours and the patient stood the whole procedure uneventfully, with stable hemodynamics and normothermia, except for skin rubor and some blisters in the left side of neck. He was transferred to the neurointensive care unit for postoperative mechanical ventilation and recovery.

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Fig. 1. The supine position, with head rotation at almost 90 degrees, was held with a Mayfield skeletal fixation head rest.

On postoperative day (POD) 1, the patient developed lip angioedema and generalized swelling of head and neck. Initially, the patient was evaluated for the possibility of superior vena cava syndrome or anaphylaxis, but neck sonography revealed neither intravascular nor perivascular lesions in the subclavian and jugular veins and the serum IgE concentration was not increased. Computed tomography showed markedly swollen soft tissues of the head and neck, especially in the left side, and necrosis of multiple muscles, including dorsal neck muscles and left sternocleidomastoid muscle. The edematous muscles compressed the bilateral internal jugular veins, but not the carotid arteries (Fig. 2). In addition, serum levels of creatine kinase (CK) (17,634 IU/L), alanine transaminase (93 IU/L), and aspartate transaminase (443 IU/L) were significantly increased and a thorough neurological examination revealed functional impairment of the right sixth, seventh, and eighth cranial nerves. Therefore, compartment syndrome of the head and neck with rhabdomyolysis was diagnosed. Treatment including sedation, analgesia, prolonged mechanical ventilation, 45° head-of-bed elevation, and rehabilitation therapy was applied and both vital signs and neurological function were closely assessed. He was successfully weaned from mechanical ventilation on POD 25 after remission of upper airway edema and transferred to an ordinary ward on POD 29. Pathology of the CP angle tumor revealed an acoustic schwannoma. He was discharged with sequelae of mild muscular atrophy at left neck and shoulder and residual neuropathy of the right six, seventh, and eighth cranial nerves on POD 51. During 3 months of intensive rehabilitation and follow-up, the appearance and muscle strength of the left neck and shoulder were recovered.

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Fig. 2. Comparison of two series of computed tomography scans of the head and neck on postoperative days 5 (A–D) and 14 (E–H), at the same level. Markedly swollen soft tissue of the face and neck, with obvious compression of bilateral internal jugular veins, was found; involvement of the left side was more severe. Ischemia and necrosis of the dorsal neck muscles and left sternocleidomastoid muscles with hypodensity are indicated by the asterisk.

3. Discussion

The positioning techniques for facilitating retrosigmoid craniotomy include lateral decubitus, park-bench, supine with head-turn, and a sitting position. Retrosigmoid craniotomy in the supine with head-turn positioning position requires the patient's head to be turned flat, parallel with the floor, and his neck flexed. Supine with head-turn position is a common positioning of retrosigmoid craniotomy for removal of acoustic schwannoma; however, extreme rotation of neck can compress and twist musculatures and vessels at the contralateral side of the neck, but excessively stretch those at the ipsilateral neck. In addition, the Mayfield skeletal fixation head rest, which maintains this surgical positioning, will maintain pressure on the neck. Direct pressure on muscles could result in compartment syndrome, which is common after severe trauma or prolonged compression, and muscle ischemia develops when tissue pressures rise to within 10–30 mmHg of the diastolic pressure.⁶ Ischemia >3 hours precipitates to increase capillary permeability, and myonecrosis and myoglobinuria can occur after 4 hours of muscular ischemia.⁷ Therefore, the surgical time is also an important risk factor which contributes to rhabdomyolysis after surgery.⁸ Reperfusion of ischemic muscle after repositioning the neck to the physiologic position can lead to muscular edema and further increase compartment pressure, which in turn, worsens muscle ischemia. In the present case, a 5 × 3× 3 cm schwannoma was located at the right CP angle, with upward adhesion to the tentorium, extension into the internal acoustic canal, downward compression of the 9th, 10th, and 11th cranial nerves, and anterosuperior compression to the 5th cranial nerve and pons toward the contralateral side. The surgeons insisted on extreme positioning of supine head-turn positioning, with head rotation almost 90 degrees to the left side within 15 hours of surgery, to provide maximal and satisfactory anatomical exposure, and the extent and duration of extreme rotation and flexion is more critical than the traditional retrosigmoid approach in which the patient's head is positioned around 75–80 degrees within 6–8 hours of surgery. Therefore, we suggest that the compartment syndrome of head and neck, by compressing jugular veins and hindering venous return from head, is the cause that produces facial and neck swelling, angioedema, and upper airway edema in the present case. Specific anesthetic strategies for the retrosigmoid approach have evolved to prevent the development of compartment syndrome associated with supine and head-turn position at our institution, including effective communication with the neurosurgical team to avoid head rotation beyond 80 degrees in moderately nourished patients, or 70 degrees in severely obese patients, a rolled-up blanket or pad placement under the shoulder to reduce the stretch and compression, avoidance of direct contact of chin and mandible with the contralateral shoulder to prevent impedance to blood flow, maintenance of a central venous pressure of 7–8 mmHg and mean arterial pressure around 65–75 mmHg, and perioperative brain relaxation with mannitol.

Postoperative rhabdomyolysis has been reported to occur after malignant hyperthermia, congenital neuromuscular disorders, propofol infusion syndrome, or external compression of musculature with muscular ischemia. In addition, surgical positions, like the lithotomy position,1, 2 the lateral decubitus position,3, 4 the hyperlordotic position,⁵ and the sitting position for posterior fossa surgery,⁹ have also been related to rhabdomyolysis after an extended surgical period. In our present case, both the propofol infusion syndrome and malignant hyperthermia were excluded, since we did not use propofol and there was no hypercapnia, acute metabolic acidosis, or hyperthermia during anesthesia. In addition, the patient had not had a central venous catheter inserted at his neck and did not have hypotension during surgery. In contrast, extreme rotation of the patient's neck did happen and persisted for 15 hours during the surgery. Although the anesthesiologists had communicated with the neurosurgeon team about possible side effects of this extreme surgical positioning, the communication was ineffective, and serious workplace conflict occurred. To avoid further conflict, we resorted to maintaining a mean arterial blood pressure and intermittent manual retraction of the left shoulder throughout the surgery instead. Therefore, extreme rotation of the patient's neck for 15 hours during general anesthesia in retrosigmoid craniotomy is the cause of postoperative compartment syndrome and rhabdomyolysis in our present case.

Rhabdomyolysis can result in severe metabolic derangement and acute renal failure, depending on the severity of muscle damage. In analyzing 148 patients with rhabdomyolysis, Sharp et al found that initial values of serum creatinine (≥1.5 mg/dL), base deficit (≥4 mEq/L), serum CK level (≥5000 IU/L), and positive myoglobinuria were the risk factors of acute renal failure in these patients.¹⁰According to Sharp's study, our present case had an intermediate risk of acute renal failure due to a serum creatinine level of 1.2 mg/dL, base deficit of 4 mEq/L, and high serum CK level of 17634 IU/L. After adequate hydration, diuretic medication and intensive care, renal dysfunction did not happen in our present case.

In conclusion, we present a case of postoperative compartment syndrome of the head and neck as a result of extreme rotation of the neck in a prolonged surgical procedure. Our neurosurgeon teams have changed their practice to avoid extreme surgical positioning, and specific anesthetic strategies have evolved for retrosigmoid craniotomy. Precautions should be made to prevent second injury when preparing the patient's surgical position. Communication with the surgeons and decreasing the compression pressure are also important. Early recognition and prompt treatment of rhabdomyolysis can prevent the occurrence of renal failure.