Infantile facial haemangioma and subclinical left ventricular dysfunction: the importance of z score in the diagnostic and therapeutic process

The use of propranolol in the treatment of infantile haemangiomas: an update on potential mechanisms of action

Currently, propranolol is the preferred treatment for problematic proliferating infantile haemangiomas (IHs). The rapid action of propranolol has been shown to be especially dramatic in IHs involving dyspnoea, haemodynamic compromise, palpebral occlusion or ulceration. Another remarkable aspect of propranolol treatment revealed that the growth of the IHs was not only stabilized, but also that the improvement continued until complete involution was achieved, leading to a considerable shortening of the natural course of IH. However, the mechanisms underlying the effects of propranolol have not been fully elucidated. Recent studies have offered evidence of a variety of mechanisms. These include the promotion of pericyte-mediated vasoconstriction, the inhibition of vasculogenesis and catecholamine-induced angiogenesis, the disruption of haemodynamic force-induced cell survival, and the inactivation of the renin-angiotensin system. This review summarizes these mechanisms and the new concepts that are emerging in this area of research. Moreover, several molecular mechanisms by which propranolol may modify neovascularization in IH have also been proposed. The antihaemangioma effect of propranolol may not be attributable to a single mechanism, but rather to a combination of events that have not yet been elucidated or understood. Further studies are needed to evaluate and verify these mechanisms to gain a greater understanding of the effects of the intake of propranolol on haemangioma involution.

Treatment of infantile haemangioma with captopril

BACKGROUND

Infantile haemangioma (IH) has recently been reported as an aberrant proliferation and differentiation of a primitive mesoderm-derived haemogenic endothelium regulated by the renin-angiotensin system (RAS), leading us to propose angiotensin converting enzyme (ACE) as a potential therapeutic target.

OBJECTIVES

To present initial results of our open-labelled observational clinical trial using captopril, an ACE inhibitor (ACEi), in the treatment of problematic proliferating IH.

METHODS

After initial screening investigations, infants with problematic IH were admitted for initiation of captopril with a 0·1 mg kg(-1) test dose orally, followed by 0·15 8-hourly over 24 h. This was then followed by dose escalation to 0·3 mg kg(-1) 8-hourly for another 24 hours. The dosage was increased to 0·5 mg kg(-1) 8-hourly 1 week later, if a noticeable involution had not already occurred. The response of IH to captopril was documented clinically and photographically before and after treatment and any side-effect was recorded.

RESULTS

Two boys and six girls aged 5-22 weeks (mean 12·9) with problematic IH were recruited with the lesions located in nasal tip (n = 1), cervicofacial (n = 3), periorbital (n = 1) and perineal (n = 2) areas, and shoulder (n = 1). Transient mild renal impairment occurred in one subject but resolved spontaneously. No other complication was observed. The IHs in all patients responded to captopril at a dosage of 1·5 mg kg(-1) daily which led to a dramatic response in three, moderate response in two, and slow response in three patients. Continued involution of IHs was observed during the follow-up period of 8-19 months (mean 15·8) in all subjects. Treatment was ceased at 14 months of age in seven patients with no rebound growth. In the remaining patient, rapid healing occurred with ongoing gradual reduction in the size and colour of a large ulcerated retroauricular lesion following 5·5 months of treatment. The lesion was excised to address its persistent distortion of the ear.

CONCLUSIONS

The response of IH to an ACEi supports a critical role for the RAS in IH and represents a paradigm shift in the understanding and treatment of this enigmatic condition.