2 Diagnosed With Mild Hemophilia A Due to Bleeds After Oral Surgery

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by Lindsey Shapiro PhD |

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Excessive bleeding after oral surgery led to two people in China, both with normal pre-operative blood clotting tests, being diagnosed with hemophilia A, according to a recent case report.

Mild hemophilia can go undetected in standard laboratory tests, and oral surgeons need to be prepared for such cases, the research team emphasized.

“The purpose of these case reports is to bring dental professionals’ attention that [clotting tests] alone cannot be used to exclude mild hemophilia, and provide reasonable evaluation and treatment procedures of bleeding patients after tooth extraction,” the scientists wrote.

Uncontrollable bleeding after tooth extraction from asymptomatic mild hemophilia patients: two case reports” was published in the journal BMC Oral Health

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Hemophilia is caused by a deficiency of blood clotting factors, leading to uncontrolled bleeding. In severe cases, spontaneous bleeds can occur, whereas significant bleeds in people with milder forms typically follow trauma or certain surgical procedures.

For this reason, tests that screen the blood’s ability to clot are often given before surgery to identify a bleeding disorder. But their ability to accurately detect mild hemophilia has been called into question, the report noted, as mild cases can escape clinical thresholds.

A research team in Wuhan described two people with normal results on initial blood clotting tests, whose hemophilia was identified due to persistent bleeding after oral surgery.

The activated partial thromboplastin time (APTT) is a standard coagulation test of the time it takes for blood to clot. An APTT of longer than normal is indicative of a clotting disorder, although what is considered a normal time range may vary by test and medical institution.

A 29-year-old man came to the scientists’ oral surgery department to have two wisdom teeth removed. He had experienced gum bleeding the previous year, and results of a coagulation test performed at the time were abnormal. He no other known clinical signs of hemophilia.

Pre-operative coagulation tests were considered normal (APTT: 32.3 seconds) and his wisdom teeth were removed without incident.

Several hours later, continuous bleeding was noted at one extraction site, and intermittent bleeding continued for several days despite clinicians’ attempts to stop it.

Five days after the surgery, the man had an elevated APTT of 53.5 seconds and an abnormal result on a fibrinogen test — another test for blood clotting. At this point, the patient recalled an elder cousin also having problems with blood coagulation.

As severe and persistent bleeding continued at both extraction sites a full week after the surgery, a factor assay was performed to determine if the man lacked a clotting factor. Levels of factor VIII (FVIII), the clotting protein missing in hemophilia A, were significantly lower than usual, and the man was diagnosed with hemophilia A.

His bleeding stabilized after two rounds of coagulation factor replacement therapy, given to supplement the deficient clotting factor.

A 41-year-old man came to the team’s hospital four days after a tooth extraction at another dental clinic with significant, continuous dental bleeding.

The man reported no abnormal findings on blood tests given before his surgery, but an APTT test performed three days after the surgery was significantly elevated (66.4 seconds). Attempts to stop the bleeding at the dental clinic had failed.

His APTT remained elevated (50 seconds) but not enough to cause alarm, the researchers wrote. Suspecting that the bleeding was related to inflammation, they cleaned the socket where the tooth had been removed. However, bleeding continued and attempts at controlling it remained unsuccessful.

Factor assays were then undertaken and showed decreasing FVIII levels, leading to the diagnosis of mild hemophilia A. FVIII supplement therapy successfully stopped the bleeding.

These two cases indicate that “APTT test results alone cannot be used to exclude the presence of mild hemophilia,” the scientists wrote. “This disease will bring great challenges to oral surgeons due to its ambiguous clinical symptom and the unreliability of APTT test.”

A patient’s detailed medical history before surgery, looking for evidence of prior individual or family bleeding problems, “may be more useful than coagulation screening tests to predict the risk of bleeding after tooth extraction,” they added. For people with a history of hemophilia or abnormal bleeding, a coagulation test should be performed and preparations for appropriate interventions to control bleeds should be made.

“As an oral surgeon, it’s important to ensure the safety of the operation, perform timely treatment for bleeding patients and provide reasonable suggestions for patients with potential bleeding disorders,” the researchers wrote.