Debulking of a gastrointestinal hemangioma alleviates coagulopathy associated with Kasabach-Merritt syndrome

A 39-year-old man was admitted to the hospital with acute massive lower intestinal bleeding. The patient had a history of multiple vascular malformations present since birth, with involvement of his left perineum and lower extremity, liver, spleen, descending colon, and rectum. He had his first major lower gastrointestinal bleed requiring multiple blood transfusions at age 18, with 7 additional major bleeding episodes during the next 20 years. These episodes occurred in the setting of chronic gastrointestinal blood loss, intermittent crampy lower abdominal pain, and chronic constipation. Between bleeding episodes his baseline hemoglobin was 11 g/dL with platelet counts of 80,000 to 100,000/mm³. Lower gastrointestinal endoscopy, performed with the patient in stable condition, demonstrated diffuse involvement of the rectum and descending colon with submucosal vascular malformations resulting in protrusion of the mucosa into the lumen, causing an overall narrowing of the lumen and rigidity of the bowel wall. No mucosal lesions were observed.

On presentation, the patient's blood pressure was 100/50 mm Hg, with a heart rate of 140 beats per minute. Laboratory studies revealed an initial hematocrit of 16.7%, hemoglobin of 5.8 g/dL, platelets 63,000/mm³, fibrinogen of 88 mg/dL, and prothrombin time of 15.1 seconds. To identify the location of this acute, massive bleeding, a technetium 99m pertechnetate–labeled red blood cell scan was obtained. This showed diffuse synchronous filling of a giant cavernous hemangioma of the rectosigmoid, with no isolated bleeding site identified. Computed tomography scan showed multiple hepatic and splenic cavernous hemangiomas and diffuse wall thickening of the rectum and sigmoid colon with multiple phleboliths within the wall of the colon (Fig 1).

The patient was treated with blood product support, including transfusion with 13 units of packed red blood cells, 4 units of fresh frozen plasma, 36 units of platelets, and 2 units of cryoprecipitate. The bleeding ceased at this point; he was started on a low residue diet and discharged from the hospital. Ten weeks later, he was taken to the operating room electively for exploratory laparotomy and resection of all or part of his intestinal hemangioma. Blood product support was required to normalize his hematologic profile before operation (Table). At laparotomy he was found to have involvement of the sigmoid, descending colon, and rectum with extensive hemangioma. The normal colon proximal to the hemangioma was moderately dilated, consistent with chronic obstruction. The hemangioma, which produced marked thickening and fibrosis of the affected tissue, extended contiguously to the subcutaneous tissues of the anoderm, left buttock, and left upper thigh. Although the sphincter complex was intact, because of the perianal involvement and marked fibrosis of the hemangioma, a sphincter-preserving coloanal anastomosis was not possible. He therefore underwent left colectomy with a low rectal anastomosis. The 2-layer hand-sewn anastomosis was performed below the peritoneal reflection between grossly normal transverse colon and a 6-cm rectal stump, the wall of which was markedly thickened by hemangioma. On microscopic examination the specimen was notable for multiple cavernous hemangiomas located in the submucosa, muscularis, and in the serosal adipose tissue (Fig 2).

At 6 weeks after resection, the patient's coagulation profile had normalized (Table), a result that persisted at 1 year. His bowel function improved dramatically after resection, with resolution of his abdominal cramping and constipation, and he has had no further episodes of bleeding during the 4 years after his operation.

Kasabach-Merritt syndrome is a rare bleeding disorder characterized by the association of cavernous hemangiomas and thrombocytopenia.^,  The disease presents in early infancy, usually with gastrointestinal bleeding or hemorrhage into splenic or hepatic hemangiomas. The vascular malformations associated with this condition grow with the organ, maintaining an equal ratio between hemangioma and normal tissue. Cavernous hemangiomas are made up of large blood-filled sinuses with scant connective tissue and hyperplastic endothelium. Endoscopically, cavernous hemangiomas appear as soft, compressible purple submucosal nodules and may become polypoid and protrude into the lumen. Thrombosis of blood within the cavernous hemangioma is common, resulting in calcification or phleboliths, which are easily identified radiographically.

Only a small proportion of patients with cavernous hemangiomas have Kasabach-Merritt syndrome. The source of the coagulopathy associated with this condition is commonly ascribed to the presence of endothelial defects within the hemangiomas producing platelet entrapment with resulting platelet activation, platelet-fibrin thrombus formation, consumption of clotting and coagulation factors, and increased fibrinolysis.^,  In the setting of an acute bleed, these processes are exacerbated. Morbidity in patients with Kasabach-Merritt syndrome, therefore, is usually caused by major hemorrhage in the setting of a chronic consumption coagulopathy. Hemorrhage in these patients is associated with an overall mortality rate of 12% and a specific mortality rate for patients with diffuse cavernous hemangiomas of 30%.^, 

Although Kasabach-Merritt syndrome is a rare condition, with less than 200 cases reported in the literature, the difficulties that arise in its treatment have generated substantial comment. The acute hemorrhage is most often managed with blood product transfusion, replacing red cells, platelets, fibrinogen, and clotting factors. The localized consumptive coagulopathy has been treated with variable success with corticosteroids, heparin, aminocaproic acid, and estrogens.^{,  ,  ,}  Because of the nature of the lesion and the patient's bleeding propensity, surgery in the setting of acute blood loss and coagulopathy is regarded as a last resort. Potentially curative therapies for intestinal hemangiomas associated with Kasabach-Merritt syndrome include sclerotherapy, radiation therapy, vascular embolization, and surgical excision.^{,  ,  ,}  The feasibility of these modalities depends on location of the lesion. Surgery is usually reserved for localized hemangiomas. Although it is clear that complete excision of the hemangioma leads to a long-term remission in Kasabach-Merritt,^,  there are limited data to support treatment by debulking the lesions.^, 

Arguments against earlier surgical management of the patient presented here were based on the assumption that the hemangioma could not be resected without high morbidity and a permanent colostomy. In addition, because of his liver and spleen lesions, even an abdominoperineal resection would result in a limited resection that may not have altered his symptoms. In this case extensive involvement of the distal colon and rectum with hemangiomas also produced a mass effect and motility disorder leading to chronic large bowel obstruction. A lifetime of low-grade intestinal bleeding resulted in chronic anemia and multiple blood donor exposures, as well as occasional life-threatening hemorrhage. The goal of surgery, therefore, was to relieve chronic obstruction and decrease his blood loss. The patient's additional improvement in coagulation profile was an unexpected additional benefit. Although further bleeding from the remaining rectal hemangioma is possible, the frequency of this should be markedly reduced by improvement in his coagulopathy. In addition, the distal, extraperitoneal location of his remaining rectal disease makes bleeding there amenable to local treatments such as sclerotherapy or radiation.^,  Although rarely curative, these modalities can provide significant palliation. During 4 years of follow-up this patient has had no further bleeding, no coagulopathy, and substantial relief of his obstructive symptoms. This case clearly demonstrates that both chronic coagulation defects and local obstructive symptoms can be alleviated by partial surgical resection of extensive co-lorectal hemangiomas.