A report published Online First by Archives of Surgery, one of the JAMA/Archives journals suggests, that the incidence of deep vein thrombosis (DVT) after general surgical operations seems to be low when preventive steps are taken, but most cases that do occur are diagnosed in the inpatient setting and most are associated with catheter use.

According to background information in the article, unless protective steps (prophylaxis) are taken, DVT occurs in up to 40 percent of general surgery patients with an associated death risk of 1 percent from a blood clot that forms in a deep vein. In the past, some surgeons have been hesitant to use anticoagulant (anti-clotting) medications to protect against DVT because of fear about bleeding, however, recent research indicates that prophylaxis is linked to significant reductions in DVT and low rates of major bleeding. The authors write:

"Few data exist regarding the specifics of DVT formation when general surgical patients receive adequate prophylaxis."

Brian R. Smith, M.D., and colleagues in the Department of Surgery at University of California, Irvine Medical Center, Orange, Calif., analyzed data from January 2008 to December 2009 obtained from the National Surgical Quality Improvement Program. For the study, researchers evaluated medical records to establish if a central catheter was in place, the location of DVT, the time of diagnosis from the index operation, whether any DVT were associated with clots in the lungs (pulmonary embolism) and how many deaths occurred.

Throughout the study period, 35 patients (1.6 percent) from a total of 2,189 patients who underwent general operations (including surgeries of the pancreas, esophagus, stomach, intestines, colon and rectum, as well as other body parts) developed DVT. The majority of cases (94.3 percent) were discovered due to the patients suffering DVT symptoms; the remainder was detected through routine screening.

The numbers of patients developing upper-extremity DVT (40 percent) or lower-extremity DVT (45.7 percent) were comparable, with 14.3 percent of patients developing DVT in both areas.

DVT was diagnosed at an average time of 8.6 days following the operation with 83 percent of DVT being diagnosed in the inpatient setting. 60 percent of patients developed DVT linked to catheters whilst 62.9 percent of patients suffered from DVT due to other underlying health problems including pulmonary embolism in 11.4 percent.

The death rate was 14.2 percent at 30 days and researchers stating an average 93 percent compliance with prophylaxis criteria during the study period.

In a concluding statement the authors say:

"The incidence of DVT after general surgical operations is low, with most cases diagnosed as inpatients. With more than half of DVTs being caused by central catheters, efforts toward DVT prevention should include closer scrutiny to the need for central catheters, including limiting the duration of central catheters, and consideration of the added use or perhaps higher dose of anticoagulation when central catheters are present."

Petra Rattue