Anesthetic management of a patient with Marfan syndrome and severe aortic root dilatation undergoing cholecystectomy and partial hepatic resection
A 47-year-old female (wt. 49 kg) was scheduled for cholecystectomy with partial hepatic resection for gall bladder carcinoma. At pre-anesthetic clinic she complained of occasional palpitation and mild exertional dyspnea. On examination, she was tall (171 cm) having mild pallor, icterus and arachnodactyly [] with arm span more than her height and mild kyphoscoliosis. Her exercise tolerance was near normal (NYHA II). Her airway examination showed high arched palate with Mallampati grade II.[] On cardiovascular examination, we found wide pulse pressure with peripheral signs of aortic regurgitation (water hammer pulse, locomotor brachialis). An early diastolic murmur was also appreciated best on second right intercostal space close to sternum. A case of Marfan syndrome was suspected clinically and further investigations were requested. Transthoracic echocardiography (TTE) showed aortic root dilatation (root diameter 52 mm) with aortic regurgitation (AR) and left ventricular eccentric hypertrophy with grade II mitral valve prolapse (MVP). Left ventricular ejection fraction was 50%. Chest X-ray showed mediastinal widening with cardiomegaly and normal lung parenchyma []. Aortic root dilatation was also vivid in computed tomography (CT) thorax [Figures and ].\nHigh risk of surgery was explained to relatives and written consent was taken. The day before surgery the patient was admitted to high dependency unit. Her recent medications were reviewed and ramipril and frusemide were stopped. Her hemoglobin was 10.2 g%, prothrombin time (INR 1.4) and her liver function test and serum electrolytes values were normal. In the morning of surgery, patient was administered morning dose of metoprolol, aspiration prophylaxis in the form of ranitidine, intravenous amoxicillin for surgical prophylaxis, Vitamin K (for mildly prolonged prothrombin time) and anxiolytic (alprazolam) as per institutional protocol. Adequate blood products were arranged. We requested a multidisciplinary involvement of anesthesiologist, cardiologist, gastrointestinal and cardiac surgeon. In anticipation of requirement for cardiopulmonary bypass, a perfusionist was available for the case. We planned for general anesthesia with controlled mechanical ventilation along with epidural analgesia. Under basic monitoring (5 lead electrocardiogram (ECG), noninvasive blood pressure and pulse oximetry), epidural catheter was inserted in T8-T9 interspace. Epidural analgesia was started at the rate of 4 ml/h with 0.125% bupivacaine with 2.5 mcg/ml fentanyl. Right radial artery and right internal jugular venous cannulation was done under local anesthesia. Patient was induced slowly with titrated dose of fentanyl (3 mcg/kg), etomidate (0.2 mg/kg), midazolam (0.05 mg/kg) and vecuronium (0.1 mg/kg) after adequate mask ventilation. Intravenous magnesium sulfate in the dose of 50 mg/kg was injected slowly over 10 minutes to decrease intubation response.[] The patient was intubated uneventfully using McCoy blade (Grade II a of Cormack-Lehane). A trans-esophageal echogram (TEE) probe was inserted post-intubation to monitor the patient's aortic root diameter. Central venous pressure (CVP), invasive arterial pressure, FloTrac continuous cardiac output (FloTrac/Vigileo™, Edwards Lifesciences, Irvine, CA, USA) and neuromuscular monitor (TOF) and other basic parameters (ECG, pulse oximetry) were also monitored. Anesthesia was maintained with oxygen–nitrous (40:60), isoflurane, fentanyl and vecuronium. We were maintaining high normal heart rate (for regurgitant lesion like AR and MR) with sinus rhythm and cardiac contractility near preoperative status. We avoided any increase in afterload by vasopressor with pure alpha agonistic action like phenylephrine. We infused perioperative crystalloid and hydroxyl-ethyl starch (130/0.4) by monitoring CVP and stroke volume variation to maintain optimum preloading. Two units of packed cell (to maintain Hb around 8 gm %) and 4 units of fresh frozen plasmas were also transfused in view of blood loss (intraoperative INR was 1.52). However, it was a major surgery (duration 4h 30 min) with major fluid shifting and blood loss (total around 1.6 L) especially during hepatic resection (segment IVB and V) time. There were two episodes of mean blood pressure drop of more than 20% of baseline, but, they were managed by intravenous titrated mephentermine injection along with fluid. Intraoperative TEE showed mild change in aortic root diameter (52-53 mm). Perioperatively hypothermia was managed by using forced air warming (Warm Touch, Mallinckrodt, USA), and hypokalemia was corrected by potassium chloride infusion. At the end of surgery, the patient was reversed with neostigmine and glycopyrrolate, but was not extubated in view of prolonged surgery, blood loss, fluid shift and metabolic acidosis (pH 7.19, base deficit of -8). She was transferred to Post Anesthesia Care Unit (PACU) with monitors, where acidosis correction was given with sodium bicarbonate slow infusion. In PACU she was monitored as in operation theater. Euvolemia, eucapnia, normothermia, analgesia were maintained. Acid base and electrolytes disturbance corrected. TTE was arranged in post-op day one to evaluate cardiac contractility, left ventricular ejection fraction and diastolic function and was found favorable for extubation. She was extubated uneventfully 18 hours of PACU admission. Day 3 morning she was transferred to general ward from where she was discharged on post-operative day 7. Patient is now under follow-up of cardiovascular surgical team.