Nephrology Dialysis Transplantation
Nephroquiz (Section Editor: M. G. Zeier)
Malignant hypertension after adrenalectomy
Case
A 48-year-old Chinese presented with bilateral blurred vision, and was found to have accelerated hypertension and funduscopic manifestation of papilloedema. He had been diagnosed as having a left adrenal tumour 2 months previously, when he first reported anorexia and left upper quadrant pain. Computed tomography (Figure 1) and subsequent laparotomy excision revealed a large adrenocortical carcinoma character- ized by moderate pleomorphism of tumour cells and mitosis. Preoperative investigation details were not known to the patient, who was thought to be normo- tensive at that time. He never reported paroxysmal palpitation or symptoms related to catecholamine excess.
His plasma potassium level was 2.7 mmol/l (normal range 3.5-5.1 mmol/l), with a bicarbonate level of 29 mmol/l and corresponding urinary potassium of 51 mmol/1. Urinary cortisol and catecholamines were within normal range.
Questions
What is the cause of his hypertension?
Answer to the quiz on the preceding page
These biochemical features and the development of malignant hypertension 2 months after adrenal tumour removal suggested renin-mediated hypertension. Possible adrenal tumour compression of left renal parenchyma and subsequent ischaemia (known as Page kidney) might have been considered in view of the substantial mass effect of adrenal tumour (Figure 1). Onset of marked hypertension after surgical adrenal- ectomy, nevertheless, was less compatible with Page kidney. Accordingly, further imaging including a 99mTc DTPA radionucleotide study and computed tomogra- phy disclosed right renal compensatory hypertrophy and left ischaemic kidney secondary to an abrupt complete occlusion of the main renal artery (Figure 2) near the aortic origin.
The disease entity in our case depicted renal under- perfusion due to renal artery stenosis, reminiscent of the contemporary experimental two-kidney, one-clip model. Since renovascular hypertension after surgical treatment for adrenal diseases is rare except in phaeochromocytoma (which might be associated with renal artery lesions) [1], the most likely cause of accelerated hypertension in this particular patient is iatrogenic renal artery injury.
Unintentional clipping or ligation injury of renal artery during adrenal surgery, albeit uncommon, should be considered among patients who returned
with hypertension after apparent successful adrenal removal. Five similar cases of iatrogenic renovas- cular hypertension following adrenal tumour or pheo- chromocytoma excision have been reported in the literature [2-5], with four of them requiring hyperten- sion cure by nephrectomy. Putatively, development of hypertension in this case was mediated by activation of the renin-angiotensin system, secondary to iatrogenic renal arterial occlusion. Increased renin secretion and circulation (as supplied by collateral renal vascu- lature) [6] resulted in refractory renin-dependent hyper- tension. Our patient underwent surgical removal of the shrunken left kidney; his blood pressure prom- ptly normalized during intraoperative occlusion of renal vasculature, and remained so thereafter since nephrectomy.
This uncommon entity of hypertension deserves emphasis, in as much as it is potentially curable-and obviously preventable.
Conflict of interest statement. None declared.
References
1. Gill IS, Meraney AM, Bravo EL, Novick AC. Pheo- chromocytoma coexisting with renal artery stenosis. J Urol 2000; 164: 2005-2006
2. Young JD Jr, Qureshi AS, Connor TB, Wiswell JG. Problem lesions in adrenal surgery. J Urol 1969; 101: 233-240
3. Castle CH. Iatrogenic renal hypertension: two unusual com- plications of surgery for familial pheochromocytoma. J Am Med Assoc 1973; 225: 1085-1088
4. Julian WA, Cole T, Fried FA. Renovascular hypertension: a rare complication of excision of pheochromocytoma. J Urol 1974; 111: 722-723
5. Wu TH, Tsai SH, Tsai CY, Huang TP. Renovascular hyper- tension after laparoscopic adrenalectomy in a patient with adrenal adenoma. Nephron 1996; 74: 464 465
6. McCormack JL, Bain RC, Kenny GM, Tocantins R. Iatrogenic renal hypertension. Arch Surg 1974; 108: 220-222
Kai Ming Chow1 Cheuk Chun Szeto2 1 Department of Medicine and Therapeutics, Prince of Wales Hospital
2 The Chinese University of Hong Kong Shatin Hong Kong China