What if Sherlock Holmes was a Surgeon?

We meet the patient for the first time and ask them to tell us the story of what brings them to see a doctor. From their story emerges the history of present illness. We supplement it with additional tests and studies. Ultimately we arrive to the diagnosis and the treatment plan. Our job as clinicians is not unlike that of Sherlock Holmes—to look for evidence, analyze it, and come up with the right answer. One of the famous quotes by the legendary detective summarizes this approach, “It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts (1).”

In 1991, the concept of ‘evidence-based medicine’ was declared to be ‘a new paradigm of medical practice.’ The Journal of the American Medical Association proclaimed a new era of medical knowledge, in which clinical evidence from randomized trials and meta-analyses was to supersede the ‘clinical experience.’ (2)  This concept, while controversial, took the medical community by a storm–the number of publications listed in PubMed with the keywords ‘evidence-based medicine’ has skyrocketed from only 7 entries  in 1984 to nearly 12,000 entries in 2015 (Figure 1).

While the emphasis on evidence-based practice has been robust and quite persistent over the past two decades, the evidence provided often conflicts with other evidence and may be overtly misleading or even just plain wrong.  One such conspicuous example was the recent excitement about avoidance of mechanical bowel prep in colon surgery (3), only to later realize that mechanical bowel prep with oral antibiotics as originally proposed by Nichols and Condon decades ago is obviously superior (4).

Has the pendulum of evidence-based medicine swung too far? At the recent 4^th Annual Chicago Colorectal Symposium, Dr. Tom Read (Figure 2), Professor of Surgery at Tufts University School of Medicine and a Senior Colon and Rectal Surgeon at Lahey Clinic, presented a keynote address entitled, “What if Sherlock Holmes was a colorectal surgeon? Evidence is the key to treatment of rectal cancer.” He quoted a study recently published in JAMA,—“Effect of Laparoscopic-Assisted Resection vs Open Resection of Stage II or III Rectal Cancer on Pathologic Outcomes. The ACOSOG Z6051 Randomized Clinical Trial”(5). It was disappointing to the surgical community to acknowledge the fact that the study had failed to demonstrate the non-inferiority of laparoscopy compared to open surgery for locally advanced rectal cancer.  Some surgeons were quick ‘throw the baby out with the bathwater’ and proclaim the end of minimally invasive surgery in rectal cancer. After all, isn’t that what her Majesty, Evidence, says? Yet, the clinical judgement could help us to find the middle ground even when the evidence seems to be clear.

One of the goals of rectal cancer surgery is to perform a complete total mesorectal excision (TME), a technique popularized by Dr. Bill Heald in 1980’s and now universally accepted as an oncologic gold standard. Completeness of TME, circumferential and distal resection margins were the study criteria for successful resection defined by the Z6051 trial.  It is possible, although not specifically addressed by the JAMA paper(5), that among the patients randomized into laparoscopic resection arm, some may not in fact have been good surgical candidates for laparoscopy. This, in turn, could have led to a technically challenging laparoscopic rectal dissection and contributed to a higher number of circumferential margin positivity and less complete TME. Keeping the results of the study in mind, surgeons might ask themselves–can a complete TME be accomplished using a minimally invasive approach in this particular patient? In a thin patient with wide pelvis and favorable anatomy, the answer can be—‘yes’, while in obese individual with narrow, deep pelvis, the answer may be ‘no’.  I think even Sherlock Holmes would agree that in medicine, just like detective work, a little bit of common sense combined with good evidence is likely to produce the best answer.

References:

1. Sir Arthur Conan Doyle. The Adventures of Sherlock Holmes (1892). A Scandal in Bohemia, p 163
2. Evidence-based medicine. A new approach to teaching the practice of medicine.  Evidence-Based Medicine Working Group. JAMA. 1992 Nov 4;268(17):2420-5
3. Zmora O, Mahajna A, Bar-Zakai B, Hershko D, Shabtai M, Krausz MM, Ayalon A. Is mechanical bowel preparation mandatory for left-sided colonic anastomosis? Results of a prospective randomized trial. Tech Coloproctol. 2006 Jul;10(2):131-5.
4. Kiran RP, Murray AC, Chiuzan C, Estrada D, Forde K. Combined preoperative mechanical bowel preparation with oral antibiotics significantly reduces surgical site infection, anastomotic leak, and ileus after colorectal surgery. Ann Surg. 201 5 Sep;262(3):416-25
5. Fleshman J, Branda M, Sargent DJ, Boller AM, George V, Abbas M, Peters WR Jr, Maun D, Chang G, Herline A, Fichera A, Mutch M, Wexner S, Whiteford M, Marks J, Birnbaum E, Margolin D, Larson D, Marcello P, Posner M, Read T, Monson J, Wren SM, Pisters PW, Nelson H. Effect of Laparoscopic-Assisted Resection vs Open Resection of Stage II or III Rectal Cancer on Pathologic Outcomes: The ACOSOG Z6051 Randomized Clinical Trial. JAMA. 2015 Oct 6;314(13):1346-55.