Platelet phenotype and function in the absence of splenic sequestration (Review)

The spleen, in addition to its role in immunity, plays key roles in erythrocyte maintenance and platelet sequestration. Loss of the spleen via splenectomy occurs in approximately 6.4 to 7.1 per 100 000 people per year globally, commonly as a life-saving emergency procedure in trauma and a therapeutic procedure in hematological and hematological malignant conditions. It is associated with increased risk of life-threatening infection and thromboembolism, presumably via loss of splenic function, but the underlying mechanisms behind post-splenectomy thromboembolism are unclear. The splenectomized individual has a two-fold risk of thromboembolism as compared to non-splenectomized individuals and the risk of thromboembolism is elevated both post-operatively and in the longer term. Although those splenectomized for hematological conditions or hematological malignant conditions are at highest risk for thromboembolism, an increase in thromboembolic outcomes is also observed amongst individuals splenectomized for trauma, suggesting underlying disease state is only a partial factor. Although the physiological role of the splenic platelet pool on platelets is unclear, platelet changes after splenectomy suggest that the spleen may play a role in maintaining platelet quality and function. In hypersplenic conditions, sequestration can increase to sequester up to 72% of the total platelet mass. Following splenectomy, a thrombocytosis is commonly seen secondary to the loss of the ability to sequester platelets. Abnormal platelet quality and function have been observed as a consequence of splenectomy. These platelet defects seen after splenectomy may likely contribute to the increase in post-splenectomy thromboembolism. Here we draw upon the literature to characterize the post-splenectomy platelet and its potential role in post-splenectomy thromboembolism.

Colonoscopic splenic injuries: incidence and management

PURPOSE

Splenic injuries that occur during colonoscopies are rare. There is no available incidence of this serious complication, and the literature is limited to case reports. Our study looks at single institution experience of splenic injuries during colonoscopy to define the incidence and management of this serious complication.

METHODS

All patients from 1980 through June 2008 sustaining a splenic injury during colonoscopy were reviewed.

RESULTS

Four patients (of 296,248 colonoscopies) sustained a splenic injury directly from colonoscopy performed at our institution (incidence 0.001%). Three additional patients were treated at our tertiary referral center after splenic injury from colonoscopy performed elsewhere. The mean age at the time of colonoscopy was 54 years (range 40-70 years). The most common presenting symptom was abdominal pain (n = 4) with a mean decrease in hemoglobin of 6.5 g/dl (range 4.5-8.5 g/dl). Splenic injury was diagnosed by computed tomography in five patients. Six patients received a mean of 5.5 U of packed red blood cells (range 2-14 U). All patients were managed with splenectomy, six patients within 24 h of the index colonoscopy, and one patient presented more than 24 h after initial colonoscopy. There was no evidence of preexisting splenic disease in any of the patients by surgical pathology, and there were no postoperative complications or deaths. The mean duration of stay was 10 days (range 7-15 days). All patients are alive at a median follow up of 22 months (range 1-164 months).

CONCLUSION

Splenic injury occurring during colonoscopy is a rare but serious complication. Patients presented with abdominal pain and a precipitous decrease in hemoglobin and have all required emergent splenectomy.