Laparoscopic Excision of Normotensive Variant Pheochromocytoma in a Case of Triple Vessel Coronary Artery Disease: The Anaesthesia Challenge

ABSTRACT

Pheochromocytomas are catecholamine-secreting tumours arising mostly from the adrenal medulla. With the advancement in surgical and anaesthetic techniques, the incidence of severe morbidity and mortality associated with surgery is low. However, concurrent coronary artery disease and pheochromocytoma continue to be a challenge due to the risk of adverse cardiovascular events. We describe the successful management of pheochromocytoma excision in a patient with coronary artery disease.

INTRODUCTION

Pheochromocytomas are catecholamine-secreting tumours commonly arising from chromaffin cells of the adrenal medulla. They are generally identified when patients present with consistent symptoms, suggestive family history, or as incidental adrenal mass. Symptoms are typically paroxysmal. The classic triad of symptoms is episodic headaches, sweating, and tachycardia.[1] To cure and prevent cardiovascular and other organ system complications associated with catecholamine excess, surgical removal of these tumours is indicated.[2] The goals of preparation for pheochromocytoma surgery are to control hypertension, control tachycardia, and normalise intravascular volume status. The preoperative adrenergic blockade, which begins 7–14 days before surgery, is the mainstay of medical treatment.[3]

Normotensive pheochromocytoma patients generally do not have a history of hypertension clinically nor documented symptoms of high blood pressure.[4] These patients have reduced urinary catecholamines.[5]

Advanced surgical and anaesthesia techniques have reduced the incidence of severe morbidity and mortality associated with this surgery in high-volume centres.[2] However, concurrent coronary artery disease and pheochromocytoma continue to be a challenge. We describe the successful management of pheochromocytoma excision in a patient with coronary artery disease.

CASE REPORT

A 71 years male patient (height 171 cms, weight 52 kgs) with no known comorbidities had acute coronary syndrome with anterior wall myocardial infarction for which he had undergone thrombolysis. He did not have any symptoms suggestive of hypertension earlier. He was diagnosed to have pheochromocytoma due to paroxysmal hypertension. His urinary norepinephrine level was 187 mcg per 24 hours of urine. He presented to us a month later for revascularisation. He had triple vessel disease and normal ventricular function. With beta-blocker (Prolomet 25 mg OD) and Angiotensin-converting enzyme (ACE) inhibitor therapy (Tab Ramipril 2.5 mg once daily), his heart rate and blood pressure were well controlled. Due to the absence of symptoms of hypertension and low urinary catecholamines, he was considered to be normotensive. He was in New York Heart Association (NYHA) functional class II. Our patient preferred to undergo percutaneous coronary intervention (PCI). Rotablation was required for the diffusely diseased left anterior descending artery (LAD) [Figure 1] increasing the risk of hemodynamic instability. Combined PCI and laparoscopic surgery were not possible due to the unavailability of a hybrid theatre. Hence, a combined decision was taken to proceed with laparoscopic excision of pheochromocytoma with a backup from the cardiac surgical team for Coronary artery bypass graft (CABG) in case of any adverse cardiovascular event. PCI was planned for a later date.

Figure 1.

Coronary angiogram showing diffusely diseased left anterior descending artery

The anaesthesia challenges, in this case, were due to recent acute coronary syndrome, the patient being geriatric, the presence of a large tumour (7 × 6 cms) [Figure 2], a low creatinine clearance of 41 ml/min, perioperative myocardial ischaemia, and the hypertensive crisis which could occur. Nitro-glycerine and sodium nitroprusside infusions were kept ready for hypertensive crisis and the cardiopulmonary bypass circuit was primed and kept ready for sustained ischaemia.

Figure 2.

Right adrenal gland tumour

Preoperatively, ACE inhibitors were stopped and beta-blocker was replaced with calcium channel blocker (Dilzem 30 mg twice daily (bd)) for the control of heart rate and blood pressure. Tab Prazosin (2.5 mg bd) was added to achieve alpha blockade. His blood pressure was 110/60 and heart rate 64/min before initiation of alpha-blocker; hence, alpha blockade therapy was instituted for 5 days only. During this therapy, his haematocrit was maintained. He did not develop adverse effects of postural hypotension. Premedication was done with alprazolam the night before surgery. On the day of surgery, prazosin was withheld to avoid hypotension.

Benzodiazepine and opioid [midazolam (0.05 mg/kg), fentanyl (3 mic/kg)] combination in titrated doses were used for induction along with a small dose of propofol (30 mg). Intubation was facilitated by vecuronium (0.1 mg/kg). For intubation response Lignocaine 1.5 mg/kg was used intravenously. Access for Invasive arterial monitoring was taken before induction. Induction and intubation were uneventful with no hypertensive crisis and no ST-segment changes on electrocardiography. Hemodynamics were stable with the initiation of pneumoperitoneum also. During manipulation of the tumour, there were multiple episodes of hypertensive crisis(Systolic blood pressure up to 300 mmHg) which were well controlled with nitro-glycerine infusion (0.5–2 mic/kg/min titrated) and esmolol (10–20 mg) along with propofol (10–20 mg) and/or fentanyl (0.5–1 mic/kg) boluses. However, just before clamping the adrenal vein, uncontrolled hypertension was associated with profound ST changes and broad QRS complex, and a near peri-arrest situation which responded to sodium nitroprusside (1 mic/kg/min for 5 min only) additionally. The ST changes and rhythm normalised. After ligation of the adrenal vein hypotension was noted which could be managed by noradrenaline infusion (0.05–0.1 mic/kg/min titrated) and volume replacement with one unit packed red cells and Ringer lactate 250 ml.

After the surgery, a transversus abdominis plane block was given for postoperative pain relief. The patient was extubated in the Intensive care unit (ICU) after half an hour. The ICU stay was uneventful. He was shifted to the ward the next day. He was discharged 3 days later and was advised to return after 4 weeks for PCI. However, he returned and underwent off-pump coronary artery bypass grafting successfully.

DISCUSSION

Literature on the management of concomitant CAD and pheochromocytoma is available as case reports only. Various approaches to management have been initial excision of pheochromocytoma then followed by CABG,[6,7] CABG first and later adrenalectomy,[8,9] single-stage combined surgery,[10-12] and PCI followed by adrenalectomy.[13] The outcomes of all the techniques have been good, with only one case having mortality due to excessive retroperitoneal bleeding during a combined procedure.[12] The benefits and risks of various approaches have been summarised in Table 1.

Table 1.

Benefits and risks of various approaches in concurrent coronary artery disease and pheochromocytoma

	Adrenalectomy followed by cabg[6,7]	CABG followed by adrenalectomy[8,9]	Combined surgery[10-12]	PCI followed by Adrenalectomy[13]
Advantages	Hypertensive crisis avoided, less strain and hence less ischaemia	Hypertensive crisis tolerated better	Reduced risk of ischaemia	Lesser incidence of crisis during PCI
Disadvantage	Catecholamine surge due to tumour manipulation can induce ischaemia, Post-surgery vasoplegia can cause ischaemia	Continued episodes of paroxysmal hypertension, arrhythmias, pulmonary edema	Bleeding retroperitoneal	Delay for surgery due to the time taken for endothelisation of the stent

Preoperative optimisation with alpha-blockers, management of hemodynamics with the use of vasodilators and beta-blockers during tumour manipulation, and use of vasopressors with adequate volume replacement after adrenal vein ligation are crucial for staged procedures. With the combined procedures haemostasis has to be addressed additionally.

CAD is generally preferred to be addressed first to minimise acute coronary events, but in this case, the patient denied surgery, and the PCI was a high-risk procedure due to long segment diffuse disease of LAD and multiple vessel involvement, therefore adrenalectomy was performed first. Preoperative alpha blockade therapy is usually administered for 7–14 days, but in this case, the patient’s heart rate and blood pressure were adequately controlled, thus prolonged alpha blockade therapy was not required.

Few studies[9-11] have reported that there was no hypertensive crisis during surgery; however, episodes of the hypertensive crisis were noted in this case only during tumour manipulation This could probably be attributed to the shorter duration of alpha-blocker therapy, as compared to the other case reports, in which patients received at least 10 days of alpha-blocker therapy. Similar labile hypertension episodes were found in a patient with aortic stenosis and pheochromocytoma, where the patient’s hemodynamics could not permit alpha-blocker therapy.[14] Lafont et al.[5] have reported that normotensive pheochromocytomas have similar intraoperative hemodynamic instability compared to hypertensive pheochromocytomas. The lack of spontaneous hypertension has been attributed to relatively low levels of norepinephrine and epinephrine preoperatively which is also seen in the present case. However, the preoperative α1-adrenoceptor antagonist has shown no benefit in maintaining intraoperative hemodynamic stability in patients with normotensive pheochromocytoma in a study by Shao et al.[15] They have also stated that it could increase the use of vasoactive drugs and colloid infusion. Although there was transitory vasoplegia after the tumour was removed in the present case, it responded to norepinephrine and volume, there was no refractory vasoplegia. Currently, there are no guidelines for alpha-blocker therapy in normotensive pheochromocytoma.

Despite the positive outcome in this patient, we recommend coronary revascularisation before adrenalectomy as this may have avoided the ST changes. Non-critical lesions or milder disease of coronary arteries may tolerate adrenalectomy. We also suggest that adequate duration of a preoperative alpha blockade whenever possible is vital to avoid, hypertensive crisis during tumour manipulation.

We conclude that coronary artery disease with pheochromocytoma is extremely difficult to manage and that the treatment must be individualised. Outcomes can be successful with a proper plan and teamwork.

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Conflicts of interest

There are no conflicts of interest.