Smokers may fare worse after colorectal surgery

Smoking has long been linked with slower recovery in general from injuries and surgeries, and now a new study finds that smokers face more complications and higher chances of death following major surgery for colorectal cancers and other diseases.

"We wanted to see if smoking has a specific effect on these patients... and really wanted to know if patients who stopped smoking had better results," said lead author Dr. Abhiram Sharma, who was at the University of Rochester in New York during the study.

Smoking constricts the flow of blood throughout the body and is thought to prevent oxygen from getting to tissues that are trying to heal, according to the authors.

In September, a review of surgeries to repair knee ligaments found that smokers tended to have worse outcomes, including not being able to get back full knee function.

For the new report, published in the Annals of Surgery, Sharma and his colleagues studied patients included in a nationally representative database of U.S. surgeries between 2005 and 2010.

Overall, 47,574 patients were included in the analysis. All had part of their colon or rectum removed, a surgery known as a colorectal resection, either because of cancer, diverticular disease or inflammatory bowel disease.

About 60 percent of the patients had never smoked, 19 percent were former smokers and 20 percent were current smokers.

The researchers looked at the 30 days after surgery to see how many patients in each group suffered either a major complication - such as severe infection, heart or breathing problems or death - or a minor complication, such as an infection at the surgical site or in the urinary tract.

Sharma's team found that current smokers had a 30 percent greater risk of having a major complication compared to patients who never smoked, and an 11 percent greater risk than ex-smokers.

Among 9,700 current smokers, for example, there were 1,497 major complications and 1,448 minor ones, whereas the 9,136 ex-smokers had 1,374 major and 1,386 minor complications. Never smokers, the largest group numbering 28,738, had 3,316 major complications and 3,462 minor ones.

Current smokers were also 1.5 times as likely to die within 30 days of surgery as never smokers.

In addition, the longer someone had smoked - that is, the greater their number of "pack years" - the stronger their chances of complications, the researchers note.

"We were not completely surprised (by the results). We know smoking is not good and there have been other studies that show smoking is a problem," Sharma said.

There were, Sharma's team acknowledges, some limitations in the study.

For example, ex-smokers were defined as patients who had not smoked in at least one year, therefore some more recent ex-smokers may have been included with current smokers, leading the benefits of quitting to be underestimated.