Abstract

Lymphatic malformations (LM) are a congenital malformation of lymphatic
vessels. There exist large, small and mixed cystic LMs. Up to the present day, the
causes of LM remain the subject of scientific research. Special sclerosing agents
such as Doxycycline, Bleocyne, Picibanil (OK-432) and other drugs are used for
sclerosing of LM. Due to the special characteristics of the impact of each drug on
the endothelium, during the early post-surgical period there occur various
undesirable effects (swelling, pain conditions, toxic effects, allergies, etc.),
moreover, the effectiveness of the used sclerosing agents is not always sufficient to
obtain a good clinical effect. The goal of our work is to evaluate the use of the
HaemoblockTM sclerotherapy in children with various forms of lymphatic
malformations. We carried out a retrospective analysis of the use of the silver poly
(acrylate) matrix (HaemoblockTM) for sclerotherapy (off-label protocol) of various
forms of LM in children who underwent treatment at the Center for Vascular
Pathology (Moscow) during the period from 2016 to 2018. After the conducted
surgery - sclerotherapy with the HaemoblockTM in children with various LMs, we
obtained the following results: excellent and good - in 6 cases, satisfactory - in 2
cases, no negative result was obtained. In the Center for Vascular Pathology
(Moscow) in 2016 - 2018, there was conducted a treatment of 8 children with LM
of various types and localization. During the early post-surgical stages (1-3 hours
after surgery), 4 children showed severe pain syndrome, which stopped on its own
without prescription of drug-induced pain killers. 12 to 24 hours after
sclerotherapy, 6 children also showed an increase in swelling in the area of the
surgery. The swelling persisted for 3-6 days, and stopped on its own. Considering
the positive results of treatment, further multi center study of the use of the
HaemoblockTM is needed for the purpose of the LM sclerotherapy in children.

Introduction

Lymphatic malformations (LM) are a congenital malformation of lymphatic vessels. This type of pathology is rare and occurs in 1,2-2,8 per 1000 of live newborns. According to the classification of the International Society for the Study of Vascular Anomalies (ISSVA), LMs are vascular malformations with slow flow characteristics. LM major complications are: inflammation in the malformation cavity, hemorrhage, progressive increase (a threat of compression of large vessels, respiratory tract, intestinal loops). Clinically, LM manifests itself as a volumetric formation of doughy consistency, which gradually increases
in size. Sclerotherapy is the advanced minimally invasive LM treatment method. Surgical removal of pathological tissues by the "open method" is also practiced, but due to the risk of recurrence, as well as a large volume of removal, resulting in the formation of large scars, this method is used less frequently, mainly when removing single-chamber large-cystic LMs, which are also mistakenly called "cystic hygromas". Special sclerosing agents such as Doxycycline, Bleocyne, Picibanil (OK-432) and other drugs are used for sclerosing of LM. Due to the special characteristics of the impact of each drug on the endothelium, during the early post-surgical period there occur various undesirable effects (swelling, pain conditions, toxic effects, allergies, etc.), moreover, the effectiveness of the used sclerosing agents is not always sufficient to obtain a good clinical effect.

Objective

To evaluate the use of the silver poly (acrylate) matrix (HaemoblockTM) sclerotherapy in children with various forms of lymphatic malformations.

Materials and methods

From 2016 to 2018, a retrospective analysis was conducted of the use of silver poly
(acrylate) matrix (HaemoblockTM) for sclerotherapy of various forms of LM in
children. Since the use of this drug was not carried out according to the official
instruction of the medicinal product, the treatment began after the parents signed
the informed consent to the treatment ("off-label" protocol). In the Center for Vascular Pathology (Moscow) there was conducted a treatment of 8 children with LM of various types and localization (Table 1), 6 boys and 2 girls. The patients age range varied from 9 months to 10 years. In terms of localization, LMs were most frequently located in the head and neck areas (in 5 patients). All the children underwent a minimally invasive surgery - sclerotherapy with the HaemoblockTM, in accordance with the protocol effective in the Center, under general anesthesia.

Table 1

Results

The results were evaluated by means of the catamnesis monitoring, an ultrasound
study was conducted over time, and MRT study was also performed when it was
Table 1 medically required. The effectiveness of treatment results is based on the use of the following level grading:
- negative - increase in the LM size, compared to the size before the surgery or a
decrease in it by less than 24%;
- satisfactory - decrease in the LM size by 25-49%, compared to the size before the
surgery;
- good - decrease in the LM size by 50-74%, compared to the size before the
surgery;
- excellent - complete absence of LM signs, or a decrease in the LM size by 75-
100%, compared to the size before the surgery.
After the conducted surgery - sclerotherapy with the HaemoblockTM in children
with various LMs, we obtained the following results: excellent and good - in 6 cases, satisfactory - in 2 cases, no negative result was obtained.
During the early post-surgical stages (1-3 hours after surgery), 4 children showed
severe pain syndrome, which stopped on its own without prescription of drug-
induced pain killers. 12 to 24 hours after sclerotherapy, 6 children also showed an
increase in swelling in the area of the surgery. The swelling persisted for 3-6 days,
and stopped on its own. We explain the obtained undesirable effects by the impact
of the sclerosing agent on the endothelium of malformation.

Clinical Monitoring

A 10-year old girl diagnosed with a large cystic lymphatic malformation in the right supraclavicular region. According to the anamnesis, 6 months ago, the child discovered a tumor-like formation in the right supraclavicular region, which gradually increased in size (photos 1, 2). No complaints other than cosmetic, associated with the appearance of a protrusion, were reported. USI and MRT examinations were conducted (photos 3, 4). According to the results of the examinations, a diagnosis of large cystic lymphatic malformation was made,

Foto 1

Foto2

No complaints other than cosmetic, associated with the appearance of a protrusion, were reported. USI and MRT examinations were conducted (photos 3, 4).

Foto 3

Foto 4

According to the protocol adopted at the Center for Vascular Pathology, under general anesthesia, there was performed a sclerosing of the pathological lymphatic cavity using silver poly (acrylate) matrix (HaemoblockTM) During the post-surgery period there was
registered a moderate swelling without pain condition. At the control examination
8 months later, the pathological formation is not detected, both visually and
according to MRT study (photos 5, 6, 7).

Foto 5

Foto 6

Foto 7

Conclusions

As a result of a conducted retrospective analysis of 8 cases of the use of HaemoblockTM for the lymphatic malformations treatment, we discovered high efficacy and safety of the drug use. Good and excellent results were obtained in 75% of cases (6 patients). Appearance of swelling in 6 children (75% of cases) and pain condition in 4 children (50% of cases) at the early post-surgery period should be reported as shortcomings, which do not require additional medical therapy. Moreover, the performed surgery is conducted in accordance with the off-label protocol. Considering the positive results of treatment, further multi center study of the use of the HaemoblockTM is needed for the purpose of the LM sclerotherapy in children.