An observational study to evaluate haemostasis action of VELSEAL-T in haemophilia patients with external bleeding

Haemophilia, an inherited X-linked recessive disorder, with an incidence of 1 per 10000 births, manifests as spontaneous or trauma induced hemorrhagic episodes in patients, progressing to chronic disability and premature mortality in untreated patients or patients with sub-optimal treatment. Haemophilia A is due to a deficiency of clotting factor VIII, Haemophilia B is due to a deficiency of factor IX and Haemophilia C is due to deficiency of factor XI. Most of current treatment for haemorrhage control in hemophilic patient is transfusion of plasma; it enhances the concentration of clotting factor in blood which boosts the coagulation process.

VELSEAL-T of Datt Mediproduct Pvt Ltd is approved by state FDA, Haryana, India as a hemostatic patch to control haemorrhage. This is an innovative Hemostatic medical device to control haemorrhage ; It consists of clotting agent (Thrombin) and anti-fibrinolytic agent (Tranexamic Acid). These constituents are held on the internal surface of VELSEAL-T. That enables the rapid coagulation when blood flows into the device, leading to sealing and stabilization of wound surfaces.

It is presumed that VELSEAL-T shows its Hemostatic action even in person with low concentration of clotting factors such as in hemophilic patients. Reason being the blood which enters the matrix of VELSEAL – T undergoes an enhancement in the coagulation process due to the presence of clotting factors.

The rationale of this study is to observe the safety and efficacy of VELSEAL-T in Haemophilia patients. The current study will collect data of haemophilia subject, if they will use VELSEAL-T as a first aid for haemorrhage control and information will be collected for the time of haemostasis and chances of secondary bleeding.

The information/ data collected during the study will provide a comprehensive overview of the outcomes associated with VELSEAL-T and factors influencing its use in the clinical management in term of Haemostasis achievement in haemophilia patient with external bleeding.

 Sample size calculation

As mentioned in the previous study (M. Elaine Eyster, Robert A. Gordon, 1981) the response within subject group was normally distributed with upper limit of 1 sigma limit (i.e. 10.85 minutes) and standard deviation 3.2 minutes. If estimate lies within one minute of the given limit, then Hypothesis (H0) to be tested will be

H0: µ ≤ 12 minutes

Which states that “Average time to cease haemorrhage in the subjects receiving VELSEAL-T haemostatic device is within 12 minutes of application of device.â€

and alternate hypothesis (H1) was set as

H1: µ > 12 minutes

In this study, the Type I error probability associated with the test of this null hypothesis is 0.05 and following parameters was taken:

Level of significance (α) = 5 %

Accepted margin (d = delta) = 10.0% of 11 = 1 approx

Standard deviation (s.d) = 3.2

Standard Normal variate (Z) = 1.645

And sample size was calculated by below formula:

Formula = N = Sample size = Zα2 *(s.d)2/(d2)

Thus, we need to study 28 experimental subjects to be able to reject the null hypothesis that the population mean of the experimental group is less than 12 minutes, by considered this value, the calculated sample size is 28 and with 20% drop-outs, the final sample size was calculated as 34.