Bleeding risk of surgery and its prevention in patients with inherited platelet disorders
Inherited platelet disorders are a heterogenous group of diseases with a wide spectrum of clinical severity. Individually, they are rare and thus challenging to study. As such, the majority of data available is from small studies and guidelines are based on expert opinion. This paper was a retrospective study aimed at evaluating the bleeding complications associated with surgical procedures in all inherited platelet disorders.
This was a multi-center, retrospective cohort study by the Scientific Working Group on Thrombocytopenias and Platelet Function Disorders of the European Hematology Association. Participating centers were asked to review records of patients with inherited bleeding disorders that underwent surgical procedures. Patients were divided into those with platelet number disorders (IPND) and those with platelet function disorders (IPFD). Data on procedures, bleeding, and use of prophylactic regimens were collected.
There were 423 patients and 829 procedures in total. Baseline bleeding scores were higher for patients with IPFD and these patients were twice as likely to have excessive bleeding after surgery as compared to patients with IPND (25% compared to 13%). Cardiovascular and urologic surgery were associated with an increased likelihood of bleeding, while the use of pre-operative pro-hemostatic agents was associated with less bleeding. ddAVP with or without anti-fibrinolytic agents was found to be the preventative treatment associated with the lowest bleeding rate. For patients with IPND, a platelet count below 68 was found to be the cutoff under which bleeding rate increased significantly.
There are numerous limitations to this study: Firstly, it is retrospective and relies on the survey filled by participating centres. It also included patient/family responses mixed in with data from medical records. Second, given the rarity of many of platelet disorders, the cohort is heavily influenced by a subset of diagnoses. While the authors make attempts to do sub-analyses, there are insufficient data to make reasonable conclusions. Third, the decision to use prophylaxis and choice of agents used was entirely dependent on the treating physician. Fourth, the authors conclusions that ddAVP and anti-fibrinolytic therapy is the most efficacious therapy for IPFD is misleading. As this was the most commonly used therapy for IPFD with a milder bleeding phenotype, it is not surprising that it was efficacious. Clearly, it would not be advisable as the only pro-hemostatic therapy for an IPFD with a severe bleeding phenotype, such as Glanzmann Thrombasthenia or another where the underlying hemostatic defect in not affected by ddAVP. Fifth, they do not provide any data on complications of using prophylaxis (ex. thrombosis with rFVIIa).