LAUSR

To JNA Readers: In routine anesthesia practice, we are often faced with difficulty in placing central venous lines in small children.1 Various reasons identified in literature mostly point toward age-related anatomic variations or skill-dependent factors. We report an unusual case of constricted internal jugular vein (IJV) secondary to a large right cerebellopontine angle (CPA) tumor in a child. Consent for publication of this case was obtained from the child’s representatives. A 5-year-old boy, weighing 20 kg, presented with a history of difficulty in walking, swallowing, and decreased hearing in the right ear over the last 1 month. Neurological examination revealed an impairment of 7th, 8th, 9th, and 10th cranial nerve function. Magnetic resonance imaging (MRI) of the brain revealed a large right-sided CPA tumor extending into the jugular foramen, displacing the brain stem contralaterally. The child was scheduled for elective excision of the tumor in left lateral position. In the operating room, after connecting noninvasive monitors, anesthesia was induced with a standard technique. The 20-G peripheral venous access and left radial artery catheterization were established. During central venous cannulation under ultrasound guidance, the right IJV diameter was observed to be very small (1.5 cm); this did not increase despite the head-down position, a 200 mL fluid bolus or application of a Valsalva maneuver. After 3 failed attempts at cannulation by 2 expert anesthesiologists, the fourth attempt was successful but with great difficulty. The catheter was secured in place and surgery proceeded uneventfully. On reviewing the MRI scan, we observed that the large CPA tumor was also compressing the right sigmoid sinus, thereby obstructing ipsilateral venous drainage (Fig. 1). As a result, maximum venous outflow was diverted to the opposite side as evident by the enlarged left-sided sigmoid sinus and dilated left IJV. A constricted right IJV due to decreased venous outflow and visibly significant difference in lumen of both IJV was apparent on MRI. It can be difficult to place central venous catheters through the IJV in pediatric patients because of age-related narrow dimensions of the central vein and the presence of valves inside it making the advancement of guide-wires difficult.2 Further, poor hydration and low central blood volume may result in an easily compressible vein which might be obscured by the weight of an ultrasound probe itself. Use of the Trendelenburg position to increase venous flow is not helpful in infants but might be of some assistance in older children aged 2 to 6 years.1,3 Our patient had an intracranial mass lesion, and institution of such maneuvers must be carried out carefully to avoid a rise in intracranial pressure. It was only after reviewing the MRI scans again that we realized