Surgery for Obese is Risky Business

Kidney cancer surgical complications in obese

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) There's a long list of problems that being overweight can cause, and we all know the list by heart. But new research shows that being fat may have additional risks for surgery including kidney damage.

A study submitted to the American Society of Clinical Oncology found that that care must be taken in obese patients with kidney cancer, because of the very high risk of complications involved.

Potential problems included unknown response to anesthesia, difficulty calculating drug dosages and several problems concerning intubation during surgery.

"Ask your doctor about help in losing weight."

Overall, data from 620 kidney cancer patients given surgery to remove their tumor was analyzed, and the study authors found that the heavier the patient, the more likely the risk of serious surgical complications occurring.

This discovery adds to the many subtle effects that fat has on human physiology, an important topic throughout the medical community. The complication risk was evaluated by calculating the amount of increased recovery time after the incident.

The risk for obese patients was not limited to anesthesia complications, however.

A separate study also found that the hormones produced by fat cells have a clear but unknown effect, hinting that the high rate of oxidization in fat cells directly damages the kidneys in some circumstances like surgery where the kidneys are especially vulnerable.

The investigator on the second study examining the science behind fat and surgical risk is Frederic T. Billings IV, MD, Msc, from Vanderbilt University in Nashville. He believes that the level of obesity in a patient can be used as a direct marker of risk for kidney damage during or after heart surgery.

In his study, published in the Journal of the American Society of Nephrology, Dr. Billings found that increasing amounts of kidney injury during surgery on obese patients may be linked to these inflammatory molecules.

Given the lowered risk of complications demonstrated when statins are used, Dr. Billings believes that the rise in kidney injuries is related to the continuing worldwide increase in obesity, which is responsible for a general increase in inflammation.

In other words, Dr. Billings states that besides being a risk factor by itself, the fat cells are responsible for the higher levels of cellular inflammation in obese patients, which can lead to the many different kinds of surgical complications found in these kinds of studies.

Dr. Billings wrote that kidney damage "complicates the recovery of up to 30% of patients undergoing cardiac surgery, promotes systemic and sternal wound infection, is associated with myocardial injury and postoperative arrhythmias, and independently predicts an eight-fold increase in the odds of death at 30 days."

Although it would be difficult to prove obesity itself is what causes the kidney injury, Dr. Billings said the correlation was clear. As written in the article, he points out that the rates of kidney injuries over the last decade "have increased despite the advances in surgical, anesthetic, and intensive care unit care that have led to reduced perioperative mortality and shorter duration of hospitalization."

In other words, the biggest change he has personally observed over that time period that could account for the rise in kidney damage has been the increasing obesity of his surgical patients.

Research presented at conferences should be considered preliminary until published in a peer-reviewed journal.

No financial ties were disclosed by the research team.

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Review Date: 
June 21, 2012
Last Updated:
June 28, 2012