Pheochromocytoma and tetralogy of Fallot: a rare but potentially dangerous combination

Preoperative Amlodipine Is Efficacious in Preventing Intraoperative HDI in Pheochromocytoma: Pilot RCT

CONTEXT

Preoperative blockade with α-blockers is recommended in patients with pheochromocytoma/paraganglioma (PPGL). The data on calcium channel blockade (CCB) in PPGL are scarce.

OBJECTIVE

We aimed to compare the efficacy of CCB and α-blockers on intraoperative hemodynamic instability (HDI) in PPGL.

METHODS

In the interim analysis of this monocentric, pilot, open-label, randomized controlled trial, patients with solitary, secretory, and nonmetastatic PPGL were randomized to oral prazosin gastrointestinal therapeutic system (GITS) (maximum 30 mg, n = 9) or amlodipine (maximum 20 mg, n = 11). The primary outcomes were the episodes and duration of hypertension (systolic blood pressure ≥ 160 mmHg) and hypotension (mean arterial pressure < 60 mmHg) and duration of HDI (hypertension and/or hypotension) as a percentage of total surgical time (from induction of anesthesia to skin closure).

RESULTS

The median (IQR) episodes (2 [1-3] vs 0 [0-1]; P = 0.002) and duration of hypertension (19 [14-42] vs 0 [0-3] minutes; P = 0.001) and intraoperative HDI duration (22.85 ± 18.4% vs 2.44 ± 2.4%; CI, 8.68-32.14%; P 0.002) were significantly higher in the prazosin GITS arm than the amlodipine arm, whereas episodes and duration of hypotension did not differ between the 2 groups. There was no perioperative mortality. One patient had intraoperative ST depression on the electrocardiogram. The drug-related adverse effects were pedal edema (1 in amlodipine), dizziness (1 in prazosin GITS), and tachycardia (6 in prazosin GITS and 3 in amlodipine).

CONCLUSION

Preoperative blockade with amlodipine is an efficacious alternative to prazosin GITS in preventing intraoperative HDI in PPGL. Larger studies that compare preoperative blockade by amlodipine with other α-blockers like phenoxybenzamine and/or doxazosin in PPGL patients are warranted.

Anaesthetic management of a large paraganglioma resection in a woman with isolated L-looped transposition of the great arteries: a case report

Background

Reports of anaesthetic management of paraganglioma resection in patients with isolated L-transposition of the great arteries (L-TGA) are rare. We focus on the preoperative evaluation, intraoperative management, and postoperative care of a frail patient with “physiologically corrected” L-TGA for paraganglioma resection.

Case presentation

We performed general anaesthesia for a 46-year-old patient with “physiologically corrected” L-TGA undergoing open large retroperitoneal paraganglioma resection. Although the preoperative medical therapy had attained its goals, the patient went through three periods of severe episodic hypertension and tachycardia as tumour manipulation released catecholamines. Goal-directed fluid therapy based on pulse pressure variation (PPV) and point-of-care transesophageal echocardiography (TEE) imaging enabled anaesthesiologists to make rapid judgments and to regulate blood pressure in a timely manner, thereby reducing the risk of heart failure caused by massive rapid fluid bolus therapy. The patient was transferred to the intensive care unit because of intraoperative hemodynamic changes and significant blood loss. Despite transient myocardial injury (elevated troponin I), no lethal arrhythmia or complications occurred perioperatively, and the patient recovered well and was discharged 1 week later.

Conclusions

Goal-directed fluid therapy combined with the adoption of TEE could effectively guide fluid administration, which is helpful for anaesthesia management during operation. We recommend the routine use of TEE in such cases.

Catecholamine-Secreting Tumors in Pediatric Patients With Cyanotic Congenital Heart Disease

Catecholamine-secreting tumors are rare among the pediatric population but are increasingly being reported in children with sustained hypoxia secondary to cyanotic congenital heart disease (CCHD). With this review, we report the clinical characteristics of these tumors in children with CCHD. The articles included in the present review were identified using PubMed through February 2019. A manual search of the references retrieved from relevant articles was also performed. Pheochromocytomas and paragangliomas (PPGL) in children are commonly associated with high-risk germline or somatic mutations. There is evidently a higher risk of tumorigenesis in children with CCHD as compared with the general pediatric population, even in the absence of susceptible gene mutations. This is due to molecular mechanisms involving the aberrant activation of hypoxia-response elements, likely secondary to sustained hypoxemia, resulting in tumorigenesis. Due to overlapping symptoms with CCHD, the diagnosis of PPGL may be delayed or missed in these patients. We studied all previously reported PPGL cases in children with CCHD and reviewed phenotypic and biochemical features to assess for contributing factors in tumorigenesis. Larger studies are needed to help determine other potential predisposing factors and to establish screening guidelines in this high-risk population. A delay in diagnosis of the PPGL tumors can lead to exacerbation of cardiac failure, and therefore early diagnosis and intervention may provide better outcomes in these patients, necessitating the need for regular surveillance. We recommend routine biochemical screening in patients with sustained hypoxia secondary to CCHD.

Multifocal pheochromocytoma-paraganglioma in a 29-year-old woman with cyanotic congenital heart disease

BACKGROUND

Multifocal pheochromocytoma/paraganglioma presenting at an early age is commonly associated with a hereditary syndrome.

CASE REPORT

A 29-year-old woman was referred for evaluation of multifocal pheochromocytoma/paraganglioma. Interestingly, her family history did not include pheochromocytoma/paraganglioma, and comprehensive genetic testing for the well-documented pheochromocytoma/paraganglioma susceptibility genes was negative. Of note, this patient had a history of a complex cardiac defect resulting in cyanotic congenital heart disease and had never undergone operative repair. Thus she lived in a chronic hypoxic state with a baseline oxygen saturation of about 80%. Laboratory evaluation found marked increases in plasma norepinephrine and normetanephrines with normal epinephrine and metanephrines. Imaging revealed 4 aortocaval masses and a right adrenal mass. After appropriate preoperative preparation she underwent successful resection of each of the neoplasms, with pathologic testing revealing multifocal pheochromocytoma/paraganglioma.

DISCUSSION

This case highlights a growing recognition of the potential development of pheochromocytoma/paraganglioma in patients with cyanotic congenital heart disease. The underlying pathophysiology and phenotypic similarities between pheochromocytoma/paraganglioma in patients with cyanotic congenital heart disease and those with mutations that lead to cellular pseudohypoxia are reviewed.

Pheochromocytoma complicated by cyanotic congenital heart disease: a case report

Coincidental cyanotic congenital heart disease and pheochromocytoma is uncommon, although some cases have been reported. We describe a girl aged 15 yr and 11 mo with pheochromocytoma and tricuspid atresia treated by performing the Fontan surgery. The patient did not have any specific symptoms of syndrome related to pheochromoytoma or a family history of pheochromocytoma. During cardiac catheterization, her blood pressure increased markedly, and an α-blocker was administered. Catecholamine hypersecretion was observed in the blood and urine, and abdominal computed tomography revealed a tumor in the right adrenal gland. Scintigraphy showed marked accumulation of (123)I-metaiodobenzylguanidine in the tumor, which led to a diagnosis of pheochromocytoma. We did not detect any germline mutations in the RET, VHL, SDHB, SDHD, TMEM127, or MAX genes. This patient had experienced mild systemic hypoxia since birth, which may have contributed to the development of pheochromocytoma.

Oxygen concentration controls epigenetic effects in models of familial paraganglioma

Familial paraganglioma (PGL) is a rare neuroendocrine cancer associated with defects in the genes encoding the subunits of succinate dehydrogenase (SDH), a tricarboxylic acid (TCA) cycle enzyme. For unknown reasons, a higher prevalence of PGL has been reported for humans living at higher altitude, with increased disease aggressiveness and morbidity. In this study, we evaluate the effects of oxygen on epigenetic changes due to succinate accumulation in three SDH loss cell culture models. We test the hypothesis that the mechanism of α-ketoglutarate (α-KG)-dependent dioxygenase enzymes explains the inhibitory synergy of hypoxia and succinate accumulation. We confirm that SDH loss leads to profound succinate accumulation. We further show that hypoxia and succinate accumulation synergistically inhibit α-KG-dependent dioxygenases leading to increased stabilization of transcription factor HIF1α, HIF2α, and hypermethylation of histones and DNA. Increasing oxygen suppresses succinate inhibition of α-KG-dependent dioxygenases. This result provides a possible explanation for the association between hypoxia and PGL, and suggests hyperoxia as a potential novel therapy.