Effect of propranolol vs prednisolone vs propranolol with prednisolone in the management of infantile hemangioma: a randomized controlled study

Incidence and treatment of infantile haemangioma in preterm infants

Infantile haemangioma (IH) are vascular tumours with a unique growth dynamic, mostly absent at birth, growth in the first months followed by involution over several years, often resulting in residual skin changes. Immune-histologically, IH cells are exclusively glucose transporter protein-1 positive.The incidence of IH is increasing with decreasing gestational age, from 1-4% in term infants to 23% in those of <1000 g birth weight, with a female and Caucasian predominance. Discovery of systemic and topical beta blockers as an effective treatment option resulted in a rapid shift away from systemic steroids towards these drugs. For preterm infants, however, data on efficacy, pharmacokinetics and long-term safety are sparse or absent. Topical treatment without systemic side effects like cryotherapy may thus be an attractive alternative at an early growth stage (<10 mm). Indications for treatment with beta blockers, mostly propranolol systemically and timolol maleat 0.5% topically, are currently extrapolated from studies in older infants. Both seem effective, but adverse effects on sleep, circulation and metabolism are well described for propranolol. Long-term outcome data for either drug are missing. In conclusion, evidence on optimal IH treatment in preterms is lacking despite their high incidence; pharmacokinetic and clinical studies are warranted.

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.

Management of infantile hemangiomas: current trends

Infantile hemangiomas (IH) are common vascular tumours. IH have a characteristic natural course. They proliferate rapidly during the early infantile period followed by a period of gradual regression over several years. Most of the uncomplicated IH undergo spontaneous involution, with a small proportion of cases requiring intervention. These are children with IH in life-threatening locations, local complications like haemorrhage, ulceration and necrosis and functional or cosmetic disfigurements. Systemic corticosteroids have been the first line of treatment for many years. Recently, non-selective beta-blockers, such as oral propranalol and topical timolol, have emerged as promising and safer therapies. Other treatment options include interferon α and vincristine which are reserved for life-threatening haemangiomas that are unresponsive to conventional therapy. This review mainly focuses on the current trends and evidence-based approach in the management of IH.

Signaling pathways in the development of infantile hemangioma

Infantile hemangioma (IH), which is the most common tumor in infants, is a benign vascular neoplasm resulting from the abnormal proliferation of endothelial cells and pericytes. For nearly a century, researchers have noted that IH exhibits diverse and often dramatic clinical behaviors. On the one hand, most lesions pose no threat or potential for complication and resolve spontaneously without concern in most children with IH. On the other hand, approximately 10% of IHs are destructive, disfiguring and even vision- or life-threatening. Recent studies have provided some insight into the pathogenesis of these vascular tumors, leading to a better understanding of the biological features of IH and, in particular, indicating that during hemangioma neovascularization, two main pathogenic mechanisms prevail, angiogenesis and vasculogenesis. Both mechanisms have been linked to alterations in several important cellular signaling pathways. These pathways are of interest from a therapeutic perspective because targeting them may help to reverse, delay or prevent hemangioma neovascularization. In this review, we explore some of the major pathways implicated in IH, including the VEGF/VEGFR, Notch, β-adrenergic, Tie2/angiopoietins, PI3K/AKT/mTOR, HIF-α-mediated and PDGF/PDGF-R-β pathways. We focus on the role of these pathways in the pathogenesis of IH, how they are altered and the consequences of these abnormalities. In addition, we review the latest preclinical and clinical data on the rationally designed targeted agents that are now being directed against some of these pathways.