Transcranial Doppler Screening in Children with Sickle Cell Disease, in Venezuela. A Collaborative Effort

Venezuela is part of the Caribbean region, where Sickle Cell Disease (SCD) is frequent, due to the slaves brought during the Spanish conquest of the Americas. Neurovascular disease and stroke, are debilitating and can be even fatal, when present in these children, as it is well known. Transcranial Doppler (TCD) is an important tool, for prevention and follow up of these patients, and is underutilized in the developing world, mainly due to cost.

OBJECTIVE

Organizing an efficient TCD program, that can reach many children affected by SCD, in Venezuela.

DESIGN/SETTING

We organized a team to provide TCD screening to children with SCD, in a collaborative effort, led by hematologists (the authors of this study). Novartis pharmaceutical provided the TCD machine -portable EZ-Dop system, DWL. Patients were assessed at a single center (Hospital Dr Carlos Arvelo, Caracas), but were referred by other centers, during a 6 month period. TCD was performed by radiologists in training, and by attending hematologists, previously trained for this procedure, at an academic, third level hospital, from January to June, 2017.

PATIENTS

Eighty eight (88) pediatric patients, aged 2 to 15, affected by SCD, either from the pilot institution or referred, were screened by TCD, at our center. Parents were required to sign an informed consent, after the procedure was explained to them. Diagnostic electrophoresis were reviewed, for entering the study. Other data were plotted, such as current treatment, laboratory values, as well as relevant clinical information.

INTERVENTION

TCD exam, at right and left temporal sides, using the standard STOP study protocol. Middle Cerebral Artery (MCA) and Anterior Cerebral Artery (ACA) velocities were assessed. Technical support from international expertise, was sought for reassurance. Normal was defined as mean velocitiy below 170cm/s. Conditional between 170cm/s and less than 200cm/s. Abnormal was defined above 200cm/s. Patients were not charged for the intervention. Collaboration from colleague hematologists, who referred their patients, was achieved. Patients who were found to be abnormal, were either transfused at our center, during the following 24 hours, or were contacted with their primary physician, for prompt intervention. Education and advice was provided to patients, if requested, as per the clinician's criteria.

MAIN OUTCOME MEASURE

TCD readings were reported in a standardize format, as Normal, Conditional or Abnormal, according to the median velocity measure, of the MCA and ACA. Recommendations and follow up was provided to the patients, on every case.

RESULTS

Ten patients 10/88 (11%) had abnormal readings, and were treated with a transfusion or partial exchange transfusion, at our institution. Their primary caregiver was contacted. Eight patients 8/88 (9%) had conditional results, and were suggested to repeat at the following session, no longer than 2 weeks. Sixty two children 62/88 (79%) had normal readings, and were suggested to repeat in 1 year.

CONCLUSIONS

TCD screening is feasible, in a collaborative effort, as an important tool for prevention and follow up, in children affected by SCD, in the developing world.