Appendix 3. Cognitive Behaviors and Representative Quotes by Subject Matter Experts
Cognitive Behavior Representative Quotes
Patient Physiology & Disease Burden Appropriate patient and procedure selection based on symptoms,
comorbidities, surgical history, physical exam findings, and cross- sectional imaging.
SME2: “I want to see what the rectus muscle width and thickness look like, whether they’re missing rectus muscle or not. And then of course what the obliques look like, how thick are they, and what that patient looks like on cat scan. Are they round on cross section? Or are they more ovalized or oblong on cross-section? Those things give me hints--the rectus muscle appearance, oblique appearance, their appearance on axial imaging in general--gives me hints on whether or not I will need to do a TAR intraoperatively.”
SME 1: “There are 3 things that we really care about. First one is smoking, patients have to be off cigarettes for at least 4 weeks. Second thing is weight. We don’t operative if the BMI is over 45 and ideally we like to get them to 35. And diabetes, we try to get their hemoglobin a1c to 7.5. Everything else is small stuff for which there is no simple answer.”
Formulates a mental blueprint of the patient's abdomen based on the workup for preliminary operative planning.
Optimizes modifiable factors to prevent intraoperative and postoperative complications.
Tactical Modification
Recognizes an unsuccessful strategy and forms an alternative using information gained from the initial failed attempt.
SME 3: “Sometimes you’ll make that 1-1.5 centimeter incision, and as you’re going up, you don’t see any muscle. All you see is fat, fat, fat. That tells me you’re too medial, I’m just cutting up into the subcutaneous tissue, so I need to back out and go a little bit more laterally to achieve access to the retrorectus space.”
SME 1: “If you find that you have big defects, which can happen, you have a couple options. One, always use the patient’s own tissue if you can. So if you have omentum or if you have the falciform, you can use that to patch up a big hole in the posterior sheath. If you don’t have any kind of natural tissue and you cannot reapproximate the hole that you’ve made, you have to use some kind of mesh. The mesh that you use is up to your own discretion. Options that are completely acceptable include biologic meshes, vicryl meshes, or even covered meshes.”
Improvises a safe solution to achieve the ultimate objective of the task in response to a deviation from the expected course.
Possesses the cognitive flexibility to generate a list of viable options for each critical step of the operation.
Exposure, Ergonomics, & Environmental Limitations Optimizes the view of the operative field to avoid inadvertent injuries
throughout the case by appropriately positioning and draping the patient, adjusting the table and lights, and clearly instructing the team on how to provide adequate assistance with minimal physical discomfort.
SME 1: “You need assistance. At the least you need one other person helping you with the operation, and frequently you end up needing two because it’s a physically demanding operation.”
SME 4: “Again, adhesiolysis, there’s a ton of little tricks to it. One of it is just about the setup of what your assistant is doing. The assistant, which is a resident or a fellow, they always want to see what you’re doing. So they grab the abdominal wall and they pull it towards themselves to roll the rectus muscle, the back of the rectus muscle’s almost looking straight up. That’s not what you want. You really do want the abdominal wall pulled almost straight up in the air so the bowel is almost making a 90 degree downward pull, and you want to work 90 degrees at all times. If you’re cutting toward the bowel at a flat angle, at 180 degrees, that’s when you’re going to have an injury and you’re going to have a problem.”
Dynamically adjusts the location, force, and angle of retraction throughout the operation to enable safe, efficient task completion.
Acknowledges personal/team limitations, environmental constraints, and available resources to mitigate negative patient outcomes.
Choice of Technique & Instruments Alternates between sharp dissection, blunt dissection, and
electrocautery for efficient and safe progression of the case.
SME 2: “I’ll typically enter sharply with either metzenbaum scissors or a knife, but typically cautery to do all the subcutaneous tissue until I encounter the hernia sac, and then I typically open the hernia sac safely, and sharply, and then I look around and if everything looks good, will use a bovie for the majority of the dissection as long as we are safe from intestine and safe from any injury. If not, clearly sharps.”
SME 3: And then the other thing with regards to directionality, when you initiate the TAR, the direction of your cautery—your cautery tip should be aiming posteriorly, should almost be aiming down towards the floor. You don’t want to initiate that direction laterally. If you aim laterally, you may get off into the semilunar line.
SME1: “Actually creating the plane …just takes a lot of patience…use the peanut at first to create that plane until you can transition into kind of a, bigger object, like a sponge stick.”
Determines the appropriate type, number, location, and size of mesh based on patient factors, degree of contamination during the case, and characteristics of the prosthetic.
Chooses appropriate instruments for the task at hand.
Maintains awareness of the instrument's tip angle and location and the adjacent structures at risk for injury.
Transitions effectively between microdissection (fine dissection maneuvers for delicate tissue or unclear planes) and macrodissection large sweeps with blunt instruments or manual dissection in avascular planes)
Safe Planes & Danger Zones
Avoids overdissection or underdissection by recognizing anatomical landmarks which serve as the boundaries of tissue dissection.
SME 2: “ I will often feel the thickness of the rectus muscle, and then it kind of tapers to linea alba [and] hernia sac medially. Then I know what is thick, is the substance of the rectus muscle. I implement cautery of the underside of, what I believe, is the rectus muscle and I just kind of, buzz buzz buzz buzz buzz, maybe from medial to lateral [or] lateral to medial. When I’m going from medial to lateral, I’ll wait until I see contractions, and then I come back lateral to medial, and when the contraction stops, I know that’s the interface of where the medial most aspect of the rectus muscle ends, and where hernia sac, linea alba, whatever, begins. So I know this is definitely rectus muscle.”
SME 3: I’ll use my bovie and make a dotted line, tiny little burn marks, at just my presumed line—my sort of “line of attack.” So I’ll start superiorly, I’ll put “dot dot dot dot” with my buzzing, always making sure I’m medial to those neurovascular bundles, medial to the semilunar line. I’ll spend a good little bit of time to confirm I am in fact medial to the semilunar line, it’s worth that extra time
Integrates multiple visual and tactile cues (rather than relying on a single cue) to determine whether dissection is proceeding in the proper plane and course-corrects when necessary.
Incises components of the abdominal wall layer by layer to minimize inadvertent violation of planes.
Proceeds from known to unknown territory.
Initiates dissection with a small incision and subsequently enlarges the incision only after confirmation of entry into the proper plane.
Maintains vigilance when navigating through areas of scar tissue that distort anatomy and increase risk for injury during dissection.
Tissue Trauma & Handling Understands the anatomy and mechanical properties of the components of the abdominal wall at each level.
SME 4: “Listen, honestly, out lateral, if you’re talking lateral to the linea semi-lunaris, there’s not really a wrong plane because if the peritoneum comes down and you’re in the pre-peritoneal plane, not a big deal. If the transversalis fascia comes down and you wanted a pre-transversalis, also not a big deal. The first of those two, pre-peritoneal is a little easier to dissect, but thin. Pre-transversalis is a little harder to dissect, but also thicker, maybe a little more bloody as you’re peeling stuff off the muscle. But in any one person, you might plane-hop from one to the other and then back again, either on purpose or just because it’s what’s giving you at the time you’re doing the dissection.”
Protects viscera from inadvertent injury.
Minimizes contact with fragile tissue and instead manipulates surrounding robust tissue for dissection when appropriate.
Offsets tension on delicate tissue by recognizing and releasing adhering attachments.
Task Completion Ensures satisfactory completion of requisite subtasks before moving on to subsequent steps.
SME 3: “I’ll spend a good little bit of time to confirm I am in fact medial to the semilunar line, it’s worth that extra time... I think that’s really important when it’s open, and especially robotically, you’re zoomed in and it’s really hard to get a feel for your three- dimensional space there.”
Regularly gauges the overall progress of an operation and maintains a running inventory of pending tasks.
Tissue Reconstruction & Wound Healing
Assesses for excessive tension when approximating tissue and reinforces reconstructed tissues under tension when appropriate.
SME 1: “To close your posterior layer you have to make sure there are no holes in the posterior layer, and any holes in the posterior layer have to be closed. If they come together without any tension, just figure-8s. Or running 2-0 vicryl is fine, even on a fenestration. If you find that you have big defects, which can happen, you have a couple options. One, always use the patient’s own tissue if you can. So if you have omentum or if you have the falciform, you can use that to patch up a big hole in the posterior sheath. If you don’t have any kind of natural tissue and you cannot reapproximate the hole that you’ve made, you have to use some kind of mesh.”
SME 2: “A complete removal of prior mesh, whatever location that mesh is in, complete removal of any and all plastic, including sutures, including tacks. So that is the thing I personally am exceedingly fastidious about, is removal of all the foreign body. We’re going to start all over again with a completely different repair.”
SME 3: “I will measure the width of my retrorectus plane, and most of my cases I use a soft polypropylene mesh at the macroporous, light-to-medium weight polypropylene mesh, and I will oversize that plane by a couple centimeters. So if I measure the plane, at say, 12 centimeters, I will measure my mesh at approximately 14 centimeters. I usually add about a centimeter to each side. And this is because if you place sutures to fixate the mesh, it ends up pulling the mesh to one side, so I want to give myself a little extra so that it won’t shift it over too much and not have enough on the other side.”
Optimizes conditions to ensure long term durability of the reconstruction.
Ensures a "giant prosthetic reinforcement of the visceral sac" by appropriately selecting the type, number, location, and size of mesh implants based on patient factors, wound class, and mesh attributes.
Recognizes when the posterior components require reconstruction and utilizes native tissue and/or prosthetics to create a contiguous barrier.
Prevents postoperative wound complications by thoroughly excising attenuated skin, devitalized tissue, and foreign bodies.
Strictly maintains sterility of the surgical field.
Anticipation & Forward Planning.
Preserves native tissue elements for possible incorporation into abdominal wall reconstruction.
SME 2: “I want it incised as close as I can to the medial edge of the rectus muscle because I want every bit of posterior rectus sheath width because I need every bit of width to close.
I don’t want to sacrifice and enter the posterior rectus sheath 2 centimeters lateral to the linea alba. I want to get it right on the edge of the linea alba, I need those 2 cm, there’s a gap I need to close.”
SME 3: ”I do try to spare some of the fascial tissue superiorly and inferiorly--that is, sub- xiphoid and suprapubic. I want to preserve as much of that fascia as I can in case I do suture fixation for the mesh. That is, I don’t cut xiphoid to pubis; I try to preserve that fascia at the apices.”
SME 4: “We always look for internal hernias and do the bowel work necessary to prevent internal hernias after bypasses from becoming a problem as well. I mention that specifically because my guy on Tuesday was a weight-loss patient from an outside hospital as well, and he had both JJ defect and a retro-alimentary limb defect. And so both needed to be repaired while we were there, because again, I don’t want him to show up again in 6 months with an internal hernia. Let’s just fix it now.”
Preserves the linea alba at the edges of the incision to minimize risk of future hernias around the margins of dissection.
Avoids sacrificing valuable domain which may result in a challenging reconstruction at later steps.
Strives to mitigate any patient-specific risk factors that may require re- entry into the abdomen or pelvis.
