Oral sildenafil as a treatment option for lymphatic malformations in PIK3CA-related tissue overgrowth syndromes

Differences in Efficacy and Safety of Sirolimus and Sildenafil in Pediatric Lymphatic Malformations

OBJECTIVES

To explore the differences in the efficacy and safety of oral sirolimus and sildenafil in the treatment of pediatric intractable lymphatic malformations (LMs).

METHODS

From January 2014 to May 2022, we retrospectively enrolled children with intractable LMs treated with oral drugs (sirolimus or sildenafil) and divided the patients into sirolimus and sildenafil groups from Beijing Children's Hospital (BCH). Clinical features, treatment, and follow-up data were collected and analyzed. The indicators were the ratio of reduction in lesion volume pre and posttreatment, the number of patients with improved clinical symptoms, and adverse reactions to the two drugs.

RESULTS

Twenty-four children in the sildenafil group and 31 children in the sirolimus group were included in the present study. The effective rate in the sildenafil group was 54.2% (13/24), with a median lesion volume reduction ratio of 0.32 (-0.23, 0.89) and clinical symptoms improved in 19 patients (79.2%). On the contrary, the effective rate in the sirolimus group was 93.5% (29/31), with a median lesion volume reduction ratio of 0.68 (0.34, 0.96), and clinical symptoms improved in 30 patients (96.8%). There were significant differences (p < 0.05) between the two groups. Regarding safety, four patients in the sildenafil group and 23 patients in the sirolimus group with mild adverse reactions were reported.

CONCLUSION

Both sildenafil and sirolimus can reduce the volume of LMs and improve clinical symptoms in partial patients with intractable LMs. Sirolimus is more effective than sildenafil and the adverse reactions associated with both drugs are mild and controllable.

LEVEL OF EVIDENCE

III Laryngoscope, 133:3192-3199, 2023.

Familial CCM Genes Might Not Be Main Drivers for Pathogenesis of Sporadic CCMs-Genetic Similarity between Cancers and Vascular Malformations

Cerebral cavernous malformations (CCMs) are abnormally dilated intracranial capillaries that form cerebrovascular lesions with a high risk of hemorrhagic stroke. Recently, several somatic "activating" gain-of-function (GOF) point mutations in PIK3CA (phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit p110α) were discovered as a dominant mutation in the lesions of sporadic forms of cerebral cavernous malformation (sCCM), raising the possibility that CCMs, like other types of vascular malformations, fall in the PIK3CA-related overgrowth spectrum (PROS). However, this possibility has been challenged with different interpretations. In this review, we will continue our efforts to expound the phenomenon of the coexistence of gain-of-function (GOF) point mutations in the PIK3CA gene and loss-of-function (LOF) mutations in CCM genes in the CCM lesions of sCCM and try to delineate the relationship between mutagenic events with CCM lesions in a temporospatial manner. Since GOF PIK3CA point mutations have been well studied in reproductive cancers, especially breast cancer as a driver oncogene, we will perform a comparative meta-analysis for GOF PIK3CA point mutations in an attempt to demonstrate the genetic similarities shared by both cancers and vascular anomalies.

Vascular anomalies: special considerations in children

The diagnosis and treatment of vascular anomalies are a large part of the caseload for paediatric interventional radiologists. Although many of the principles of sclerotherapy and embolisation are the same in adult and paediatric practice, there are some key differences in the approach for children, including some longer term thinking about managing these chronic diseases and their impact on a growing child. Vascular tumours are not often seen in adult IR practice and the rarest can be life threatening; knowledge of the commonest types and the role IR can play in their management can be instrumental in ensuring that children get appropriate treatment in a timely manner. Vascular anomalies also encompass some conditions associated with complex overgrowth, a subject that often causes confusion and uncertainty for interventional radiologists. This paper presents a simplified and practical approach to this spectrum of disease.

Lymphatic flow modulation as adjunct therapy for septic shock

The lymphatic system is an important component of human health and is critical in maintaining microcirculatory flow and immune system homeostasis. During septic shock, increased capillary permeability results in excess filtration of intravascular fluid and solutes producing interstitial edema with subsequent hydrostatic and oncotic gradient breakdown. The accumulation of interstitial fluid results in impaired solute exchange, leukocyte signaling, and aberrancy in capillary flow. Modulation of lymphatic flow during times of interstitial volume overload such as septic shock may decrease interstitial volume resulting in improved perfusion, decreased end-organ damage, and contribute to disease resolution. Multiple studies in both humans and animals have shown nitric oxide to be a potent modulator of lymphatic function. The present study suggests a hypothetical adjunct therapy for patients with septic shock through the use of phosphodiesterase inhibitors, which may improve microcirculatory flow by decreasing interstitial fluid volume via increased lymphatic fluid drainage.

Application of the adenosine triphosphate sensitivity assay in infantile vascular anomalies

Background

The term vascular anomalies include various vascular tumors and vascular malformations, among them infantile hemangiomas and capillary malformations are the most well-known associated diseases in early ages. Multiple drugs have been introduced for intervention, but susceptibility test in vitro were scarcely reported.

Objective

To evaluate the inhibition effect of different drugs by adenosine triphosphate sensitivity assay in vitro before the treatment of infantile hemangiomas and capillary malformations.

Methods

Specimens were selected from 5 cases of infantile hemangiomas and 11 cases of capillary malformations. Propranolol, rapamycin, sildenafil and itraconazole were tested for their growth inhibition effect by using the adenosine triphosphate sensitivity assay.

Results

Propranolol demonstrated inhibitory effects on infantile hemangiomas cells. Rapamycin and itraconazole both showed inhibitory effects on infantile hemangiomas cells and capillary malformations cells. Sildenafil has no growth inhibitory effect on infantile hemangiomas cells or capillary malformations cells.

Conclusion

Adenosine triphosphate sensitivity assay is a sensitive and useful testing method before the management of vascular anomalies, and individualized medication suggestions for the choice of therapeutic drugs were offered based on the testing result and together with a comprehensive evaluation of each infant.

A large retroperitoneal lymphatic malformation successfully treated with traditional Japanese Kampo medicine in combination with surgery

BACKGROUND

Current treatment options for lymphatic malformations (LMs) are multimodal. Recently, the effectiveness of treating LMs with Eppikajyutsuto (TJ-28) has been reported. TJ-28 is a kind of oral herbal medicine classified as the traditional Japanese Kampo medicine.

CASE PRESENTATION

A 12-year-old girl was admitted to our hospital for intermittent upper abdominal pain. Radiological examinations revealed a large (9.5 × 5.8 × 10.0 cm) retroperitoneal LM, which was suspected to adhering and stretching both pancreas head and duodenum. The large retroperitoneal tumor resection might induce involving complications because of the size and the location. Therefore, we used TJ-28 in order to diminish the tumor size before surgery. The patient received oral doses of 7.5 g/day (2.5 g × 3 times/day) of TJ-28. Six months after the medication, the tumor decreased markedly to 3.5 × 1.5 × 1.2 cm in size. Thereafter, the mass was sub-totally resected (95%) via a 3 cm trans-umbilical incision without any surgical complications.

CONCLUSIONS

We reported a case of successfully treated retroperitoneal LM with the combination treatment of TJ-28 and surgery. Based on our experience, this TJ-28 treatment option may be very useful in treating cases of LMs having surgical difficulties because of size and/or location.

Long-Term Follow-Up of Lymphatic Malformations in Children Treated with Sildenafil

BACKGROUND/OBJECTIVES

Lymphatic malformations (LMs) are challenging to treat. Reports on the benefits of sildenafil for LM management have been mixed. This study evaluated long-term clinical outcomes of pediatric LM patients after sildenafil treatment.

METHODS

A retrospective chart review was performed on pediatric LM patients treated with sildenafil in the past 5 years. Patients were also contacted to complete a survey of comprehensive questions about their LM after sildenafil and subsequent interventions.

RESULTS

Of 12 patients identified, 10 (83.3%) participated in the follow-up survey. The average age was 8 years (range 4-16 yrs), median treatment duration was 9 months, and the average time of follow-up after sildenafil was 4 years; one patient is still taking sildenafil. Ten patients surveyed (83.3%) reported positive therapeutic response, with improvement in the size and compressibility of their LM during posttreatment clinical visits. Six received additional interventions (four sirolimus, one sclerotherapy, one surgery) after sildenafil was discontinued, with all but one reporting a positive response to subsequent interventions. Minor side effects at the time of sildenafil treatment included mild flushing, dizziness, and transient nausea, but no adverse effects were reported at the long-term follow-up.

CONCLUSION

This is the first report of long-term follow-up of pediatric LM patients treated with sildenafil. Our findings suggest that sildenafil is beneficial for the symptomatic treatment of LMs. Additional analysis on the role of sildenafil as adjuvant therapy is necessary to optimize the use of this medication in the management of complex LMs.