Surgical Infection in the Age of Minimally-Invasive Surgery

Today marks about 4 years since Prescient Surgical was founded, conveniently marked by the company’s incorporation in the fine state of Delaware. After a full year of exploring various unmet needs in hyperkalemia to Raynaud’s phenomenon as Innovation Fellows in the Stanford Biodesign program, the founding team began to rally around what we called “The SSI Project.” With strong support from the surgical community at Stanford and beyond, and under full sail with the trade winds of public reporting and fines implemented with the Affordable Care Act, it was clear we were chasing down a critical unsolved problem in surgery that required immediate attention.

Naturally, I remain convinced of that fact today, and am thrilled by the progress we’ve made as a company and community towards reducing surgical site infection. Yet from the moment we began this journey, the requisite gauntlet of venture capitalists, health systems, BigCo’s, and physician interaction have buffeted us with a recurring, unseemly paradox that I’d like to address here—mainly, that the evolution of minimally invasive surgical techniques (predominantly laparoscopic surgery) has all but eliminated SSI.

Well…so why do we still see so many infections? Is it because laparoscopic / MIS techniques are in fact a panacea, but have not yet been fully adopted? Probably not, and for the past 5 years at ASCRS we’ve seen laparoscopic adoption in colorectal surgery stagnate at around 30-40%, even as the video game generation enters its prime. Laparoscopic techniques simply aren’t or can’t be used in the majority of some of the most complex surgeries.

In my position I am privileged with access to some of the world’s greatest minds in surgery, and I’m hearing a consistent belief that the next decade of surgical development will be about OR safety, not necessarily OR “MIS-ness.” One prominent single-port laparoscopic surgeon put it this way—“The impact in cholecystectomy was enormous, but when you look at more complex procedures like colectomy, you are taking out a colon, you are extracorporealizing a contaminated specimen. It’s fundamentally invasive, and within that big-picture context, MIS techniques offer real, but comparatively diminished benefits.” He advocates MIS “right-sizing,” that is mitigating patient risk in ways that might include laparoscopy when appropriate as opposed to the uncompromising pursuit of a near-incisionless nirvana. I was surprised to hear this from a surgeon that could perform a single-port colectomy wth one hand tied behind his back! It’s all about striking a balance between the risk and global invasiveness of each surgery with the each surgeon’s ability to perform it effectively and efficiently.

Is it because there are large financial interests that would like you to believe that the increased costs of laparoscopic surgery are justified by unilateral improvements in surgical care? Perhaps. I would never question the net benefit of laparoscopic approaches, but particularly when it comes to SSI, the data are mixed, and high SSI rates persist.

Consider Covidien / Medtronic’s clinical dossier summarizing the benefits of laparoscopic approaches in colorectal surgery (http://www.medtronic.com/content/dam/covidien/library/us/en/clinical-procedural-therapy/colorectal/colorectal-global-value-dossier.pdf):

“Surgical Site Infection: Rates of surgical site infection are consistently lower (often significantly) with laparoscopic colorectal surgery than open colorectal Surgery.”

Covidien data

By “often significantly,” Medtronic means that studies do not always show this benefit with statistical significance, and at times have been associated with higher infection rates in colon surgery. Though the weight of evidence supports the notion that laparoscopic approaches reduce the risk of SSI, there are still infections in laparoscopic surgery (perhaps 4-17% based on the data presented by Medtronic, though the most recent studies, and NSQIP rates at high-volume laparoscopic centers would suggest rates of 7-12%, and prospective studies generally find rates of 15-20%+). We shouldn’t be surprised either. However small, the resulting incisions are still prone to intraoperative contamination and reduced immunological activity. Even with laparoscopic approaches, a comprehensive wound care plan is warranted.

Gloves, Colon Surgery, and…Parachutes

Editor’s Comment: I’d like to welcome back Dr. Goldfarb for another guest post, this time to discuss the importance of glove changes in relation to preventing wound contamination.

When I was training in General Surgery, from 1967-1972, the every other night on call rotation was not the most rigorous part of the ordeal of training. The harder part was the daily routine working under strict surgeons who themselves were not even allowed to get married during their training. The Chief of Surgery was a meticulous surgeon who demanded total silence during surgery and total focus on the part of all participants. Other than opening and closing the abdomen, he performed all of the surgery on his private patients. The residents were responsible for the clinic and/or non-private patients. But the “eyes and spies” of the Chief of Surgery were everywhere, and if a resident skipped steps during an operation, it was expected that an OR nurse would report that misdemeanor to the Chief.  And you might be told to “Go home,” if you omitted any of these critical steps, if you omitted any steps.

One of the steps that became tattooed on my mind was the frequent glove changes during surgery, a critical step in preventing bacterial contamination of the surgical wound.  The glove changes during open bowel surgery would occur automatically every one to two hours. We changed gloves even if they had not become shriveled at the fingertips or covered with blood or stool, or otherwise have any obvious holes. The nurse or often the senior surgeon would simply say, “Let’s change gloves.” Then, after the bowel surgery, we washed out the wound, usually with a bulb syringe of saline. Before closing, we ALWAYS changed gloves. If you began to close a wound after an intestinal operation and did not change gloves, you wouldn’t just “Go home,” but rather might “Burn in hell!” as a result of this transgression. Verbal abuse aside, you were very sternly reminded that you might be responsible for seeding a wound infection in the patient. And if you caused a deep wound infection, you guaranteed a long course of healing, with prolonged hospital stay and eventual incisional hernia.

There have been so many myths perpetrated throughout surgical history. Are frequent glove changes during colon surgery one of those myths? As a “type A” compulsive surgeon, I did not want to tempt fate and so I changed my gloves often and ALWAYS before closing a wound. An article, “Bacterial Migration Through Punctured Surgical Gloves Under Real Surgical Conditions,” Huber N et al., BMC Infectious Diseases, 2010;10:192, stressed that “unnoticed perforations of surgical gloves are not uncommon and that their frequency increases with duration of wear. Suggested preventative measures to lower the risk of glove perforation include a change of gloves at least every 90 minutes, the use of double gloving, or the strengthening of common glove puncture sites.”

So maybe it was not a myth regarding the undetected glove punctures and contamination of wounds. But, beyond unnoticed perforations, I was also concerned with the direct contamination of the wound by gloves that had created a bowel anastomosis, just a little earlier in the operation.  How can a surgeon use the same gloves that touched stool to close a wound? In either case, touching a wound with a hole in the glove finger or touching a wound with stool from a bowel anastomosis could both cause wound infection.  Modern measures to decrease wound infection for colon surgery, ranging from type of bowel preparation to type of wound preparation may all help decrease the high rate of wound infection. But perhaps simply not touching a wound with a hole in the glove or not touching a wound with stool on the glove are also significant, and too often ignored. You do not need a randomized double blind study to test the validity of a parachute.