3. HISTORY
• First published in 1886 by Felix Frankel, who
described a young woman suffering from
intermittent attacks of palpitations, anxiety,
vertigo & headache.
• Successful surgical management of
pheochromocytoma was described in 1926 by
both César Roux and Charles Mayo.
4. Epidemiology
• Affects ≈0.2% of hypertensive individuals.
• Males and females are affected equally.
• The peak incidence in sporadic cases lies
between the ages of 40 and 50.
• Familial cases tend to be manifested earlier.
5. Clinical features
• The classic triad of headache, diaphoresis, and
palpitations.
• Hypertension is present in 90% of cases and
may be episodic or sustained { 50 % }.
• Only 0.5% of patients with hypertension and
suggestive features will ultimately prove to
have the disease.
7. • “The 10% tumor”
– 10% bilateral
– 10% malignant
– 10% extra-adrenal
– 10% familial
– 10% multi focal
– 10% occur in children
8. BIOLOGICAL TIME BOMB
• Cardiac decompensation suggestive of acute MI –
precipitated by partial necrosis of the tumor with
sudden release of a bolus of epinephrine & NE
into the blood stream.
• Causes of paroxysms:
– Urination
– Vigorous physical exercise
– Defecation
– Sexual intercourse
– Ingestion of alcohol
9. • In unprepared pts. , lethal paroxysms with
inavasive procedures like
– Angiography
– Labor & delivery
– Diagnostic needle biopsy
– GA
– Surgical procedures.
11. Biochemical Diagnosis
• Detection of elevated levels of catecholamines
and their metabolites in body fluids.
• Measurement of 24-hour urine levels of these
compounds.
• In 2002, measurement of free metanephrines in
plasma was introduced as an alternative
screening tool
– High sensitivity ≈99%
– A one-time blood test.
12. • Tests performed during episodes of acute
pain, critical illness or urgent hospitalization
may be misleading.
• Biochemical testing is ideally performed
when the patient is as free as practically
possible of all confounding factors.
13. • A urine collection may be considered positive if
total metanephrines or any single catecholamine
fraction (epinephrine, norepinephrine or
dopamine) is elevated above its cutoff value.
Clonidine suppression testing:
– Measurement of plasma free normetanephrine
levels after the oral administration of 0.3 mg of
clonidine may help clarify equivocal test results.
14.
15. Localisation
CT:
• Better anatomic definition for operative
planning.
• Images the normal contralateral gland.
• But additional extra adrenal
pheochromocytomas may be overlooked.
• Routine scan from the diaphragm to atleast
below the bifurcation of the aorta.
16. MRI:
• Lack of radiation exposure
• Clear definition of surrounding vascular
structures.
Disadvantages:
• Relative lack of availability
• Claustrophobia
• Cost
• Anatomic detail
17. • Both CT & MRI provide excellent images of the
liver & periaortic lymph nodes { in metastatic
disease }.
18. MIBG scanning:
Scintigraphy with 131I- or 123I-labeled
metaiodobenzylguanidine
• To image or search for bilateral tumors as in
MEN type 2 syndromes.
• To identify multiple tumors.
• Mediastinal, intracardiac tumors & bone
metastases.
Unfortunately,
• Thyroid must be blocked by oral iodine
consumption
• Repeated scans required for ≈3 days.
• Location not precise.
23. • Adverse changes:
– Intraoperative HTN:
• Stimulation of catecholamine release by
– anesthetic induction agents &
– direct manipulation of the tumor.
– Postoperative hypotension.
• Peripheral arterial vasodilation
• Dramatic increase in venous
capacitance.
Cardiovascular collapse
24. • As soon as the biochemical diagnosis of
pheochromocytoma has been confirmed, α-
adrenergic blockade is initiated to protect
against hemodynamic lability.
25. • Phenoxybenzamine:
10 mg twice daily. The dosage can be titrated
upward every 2 to 3 days to a maximum of 40
mg three times daily to achieve normalization
of heart rate and blood pressure.
• The period of preoperative conditioning lasts
at least 2 weeks to allow adequate reversal of
α-adrenergic receptor down-regulation.
26. • Phenoxybenzamine is a nonspecific,
noncompetitive (irreversible), long-acting
(half-life of 24 hours) α-adrenergic antagonist.
– Nasal congestion - indicator of adequate blockade.
– Phenoxybenzamine provides the most complete α-
blockade.
– Its pharmacokinetics permits serum drug levels to decay
in parallel with catecholamine levels postoperatively
Side effects:
– postural hypotension
– nasal congestion
27. – Alpha 1-selective agents – prazosin & doxazosin.
– Calcium channel blockers.
– β-Blockers may be administered after adequate α-
blockade has been achieved in the subset of patients
with persistent tachycardia.
• 3 days preoperatively
• Propranolol - 10 mg thrice daily
29. Intraoperative management
• Invasive hemodynamic monitoring.
• Meticulous Fluid management.
• Minimum manipulation of the tumor.
• Anesthetic team must be prepared to
administer supplemental IV α-and β-blockers,
as well as vasopressors, when necessary.
30. • Control of acute HTN:
Sodium nitroprusside
Intermittent small doses of Esmolol.
• Hypotension coincident with tumor excision:
Dopamine
Short bolus administration of
Ephedrine or Phenylephrine
31. • Blood infusion.
• Ventricular arrhythmias
Lidocaine – bolus followed by a constant
infusion.
32. • Surgery is curative in greater than 90% of
pheochromocytoma cases.
• Laparoscopic approach.
• Laparoscopic resection is contraindicated
when preoperative imaging demonstrates
local invasion.
33. Postoperative management
• Need for vasopressors….
• Monitoring in an ICU for 24 hrs
• 24 hr urine collection for matanephrines &
catecholamines after 2 weeks.
• Similar annual screening for at least 5 yrs.
