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

Management and Outcomes of Pediatric Lymphatic Malformations: A Systematic Review From the APSA Outcomes and Evidence-Based Practice Committee

BACKGROUND

Significant variation in management strategies for lymphatic malformations (LMs) in children persists. The goal of this systematic review is to summarize outcomes for medical therapy, sclerotherapy, and surgery, and to provide evidence-based recommendations regarding the treatment.

METHODS

Three questions regarding LM management were generated according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Publicly available databases were queried to identify articles published from January 1, 1990, to December 31, 2021. A consensus statement of recommendations was generated in response to each question.

RESULTS

The initial search identified 9326 abstracts, each reviewed by two authors. A total of 600 abstracts met selection criteria for full manuscript review with 202 subsequently utilized for extraction of data. Medical therapy, such as sirolimus, can be used as an adjunct with percutaneous treatments or surgery, or for extensive LM. Sclerotherapy can achieve partial or complete response in over 90% of patients and is most effective for macrocystic lesions. Depending on the size, extent, and location of the malformation, surgery can be considered.

CONCLUSION

Evidence supporting best practices for the safety and effectiveness of management for LMs is currently of moderate quality. Many patients benefit from multi-modal treatment determined by the extent and type of LM. A multidisciplinary approach is recommended to determine the optimal individualized treatment for each patient.

LEVEL OF EVIDENCE: 4

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.

Complex lymphatic malformations in pediatrics: a review of treatment options

INTRODUCTION

Lymphatic malformations (LMs) are low-flow lesions resulting from abnormalities in the development of lymphatics. The management of these lesions is complex and involve the collaboration of many specialties. The purpose of this review is to summarize current knowledge regarding the different therapeutic options used in complex lymphatic malformations, analyzing their indications, efficacy and complications.

EVIDENCE ACQUISITION

A search was made using the algorithm: "(lymphatic abnormality OR lymphatic malformation OR lymphangioma OR cystic hygroma) AND (extensive OR giant OR complex) AND (therapeutics OR treatment) AND (child OR children)". Of the 120 articles found, 53 were included.

EVIDENCE SYNTHESIS

Historically, surgery was the treatment of choice for this type of lesions. However, excision was often incomplete, associated with high rates of recurrence and severe complications. The use of sclerotherapy emerged as a minimal invasive option appropriate in selected cases as a single or adjuvant therapy. Inhibitors of the mammalian target of rapamycin, such as sirolimus, now play a central role in the treatment of complex malformations resistant to sclerotherapy, recurrent after surgery or more extensive malformations that affect vital structures. Other therapeutic options as sildenafil and laser ablation are also recognized as effective in selected cases.

CONCLUSIONS

Looking through the literature over the last decade authors realize that surgery had gradually been replaced by less invasive options such as sirolimus with or without adjuvant sclerotherapy. In conclusion, each treatment option seems to have its own indications and characteristics, which must be considered in therapeutic decision and individualized for each patient.

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.

Effect of long-term phosphodiesterase-5 inhibitor use on refractory lymphatic malformations in adult and teen patients

Lymphatic malformations (LMs) are rare congenital anomalies. LMs are often refractory to standard treatments, including surgical resection, debulking, and sclerotherapy. Use of sildenafil, a phosphodiesterase-5 inhibitor, for treatment of pediatric LMs has been reported with demonstrated benefit to some patients. This case series reports treatment of three patients (aged 14-37 years) suffering from complicated or refractory LMs with a low-dose oral phosphodiesterase-5 inhibitor, resulting in significant clinical improvement.