Acute swelling of salivary glands is a clinical entity which may affect both the parotid and submandibular glands and may present as a postoperative complication after general or even spinal anaesthesia. Postoperative parotitis has been described after abdominal, orthopaedic and neurological surgery [1-3]. Acute submandibular swelling has been reported in one case after abdominal hysterectomy  and in one case following surgery for bilateral optic nerve meningioma .
We report the case of a 44-yr old, ASA I patient, admitted to the neurosurgical department for brain tumour surgery. He had neither medical nor surgical history. A few days before admission, he complained to a neurologist of vision problems and cognitive dysfunction. The physical examination was otherwise unremarkable. The brain computerized tomography (CT) scan revealed an intraventricular tumour located in the left occipital region. Treatment consisting in carbamazepine 200 mg twice a day was started 48 h before hospital admission. The patient was premedicated with alprazolam 0.5 mg and atropine 0.5 mg given orally 1 h before surgery. Anaesthesia was induced intravenously with remifentanil infused at 0.5 μg kg−1 min−1 and a bolus of 2 mg kg−1 propofol. After an uneventful intubation facilitated with rocuronium 0.6 mg kg−1, the patient was ventilated with an air/oxygen mixture (FiO2 0.5). Anaesthesia was maintained in normocapnic and normothermic conditions with remifentanil infusion (0.25 μg kg−1 min−1) and 1 minimal alveolar concentration (MAC) sevoflurane. The patient was placed in prone position with the head maintained in the Mayfield holder and 15° tilted to the left side. During surgery, the patient received mannitol 20% 200 mL and diuresis was compensated with crystalloids and colloids. At the end of the 5 h procedure, the patient was awaken and extubated in the operating room. At that time, neurological examination did not reveal any neurological deficit. The patient was then transferred to the intensive care unit (ICU). Within the first hours following admission to the ICU, he complained of abundant saliva secretions and developed a bilateral painful swelling of the anterior submandibular region, predominant on the left side. He presented some degree of dysphonia and had difficulties to swallow but could breathe normally. The serum amylase level measured at that time was 189U L−1 (normal value <115 U L−1) and the serum C-reactive protein (CRP) value was 1.7 mg dL−1. Ultrasonography and CT scan examinations revealed a bilateral swelling of the submandibular glands predominant on the left side with inflammatory signs, and an enlargement of the salivary channels without evidence of obstruction (Fig. 1). The enlargement extended to the para-laryngeal area on the left side. The parotid glands were normal. Clinical examination performed by an ENT specialist confirmed the diagnosis of anterior submandibular sialoadenitis without evidence of pus at the orifice of the salivary ducts. No culture of salivary secretions was performed. The patient was treated with steroids and non-steroidal anti-inflammatory drugs. The second day after surgery, the serum amylase level was 187 U L−1. The CRP was 9.5 mg dL−1 and was associated with increased white blood cell count (22 000 L−1) and hyperthermia. The patient was then additionally treated with antibiotics (clarithromycin 500 mg i.v. twice a day). On day 3, the swelling of the submandibular region started to decrease. The symptomatology resolved within 6 days except for a mild degree of dysphonia. The patient was discharged from the hospital 1 week after surgery with normal biological tests. Histopathological analysis of the brain tumour revealed the diagnosis of meningioma.
Inflammation or infection of the salivary glands is an uncommon although already reported complication of surgery [1-5]. This complication usually presents a number of characteristics. It much more frequently affects the parotid than the submandibulary glands . It has been mainly reported after major abdominal and orthopaedic surgery  but has also been documented after long lasting neurosurgical procedures in patients operated in the sitting position . It occurs within a variable delay after surgery, ranging from the first postoperative hours to 15 weeks , with a peak incidence between postoperative days 5 and 7 [6,7]. It may be suppurative or not, and associated or not to sialolithiasis [1,5]. The reported factors that could favour the occurrence of this complication include the position of the head of the patient, a luxation of the temporomandibular joint during intubation, medications such as antihypertensives, antihistamines and antidepressants, dehydratation whatever the mechanism, malnutrition and a poor oral hygiene [2,3,5].
When compared to the above-mentioned considerations, the present report refers to a bilateral, predominantly left sided swelling of the anterior submandibular glands without parotitis, that occurred within the first postoperative hours following a 5 h duration neurosurgical procedure in the prone position. Cases reported in the neurosurgical literature developed within a delay of 48-72 h after surgery in patients operated in the semi-sitting position . Those cases mainly affect the parotid gland except for one case of submandibular swelling described after surgery for optic nerve meningioma . Our patient was positioned with the head slightly tilted to the left and the lesion developed predominantly on the left side . In the literature, parotitis that develop in patients whose head is tilted to one side usually affect the gland located on the opposite side. However, one can reasonably assume in this case that the slight rotation of the head during a long duration surgery can be accounted for stretching and dilation of salivary ducts, salivary stasis and development of acute submandibular swelling. Our patient received carbamazepine as the sole preoperative medication and had no sign of preoperative systemic dehydration. He was given 200 mL 20% mannitol for brain relaxation during surgery but was kept normovolaemic with i.v. crystalloids and colloids. As far as no pus was seen at the orifice of the salivary channels, the patient was first treated with anti-inflammatory drugs. Thereafter, he also received clarithromycin 500 mg twice a day because of persisting symptoms associated to an increase in CRP with raised white count. According to literature reports, failure of response to therapy within 48 h is an indication for intravenous antibiotics .
In summary, we report an acute bilateral submandibular swelling in a healthy patient after a 5 h neurosurgical procedure in the prone position. This swelling, evidenced by ultrasonography and CT scanning, was responsible for excessive saliva secretion, dysphonia and painful dysphagia. It resolved within 1 week after treatment with anti-inflammatory drugs and antibiotics. This complication quite markedly differs from those usually reported in the literature regarding the main gland affected, the delay after surgery and the potential role of contributing factors.
1University Department of Anaesthesia and Intensive Care Medicine, CHR de Citadelle, Liege, Belgium
2Department of Radiology, CHR de Citadelle, Liege, Belgium
3Department of Neurosurgery, CHR de Citadelle, Liege, Belgium
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