SMOOTH OPERATOR The surgical team should be ready with the surgeon's choice of mesh.

How do surgeons achieve efficient and effective hernia outcomes? Well, that depends. Is the hernia clean or contaminated? Where is the defect located and how big is it? Is a laparoscopic or open approach best? Which mesh option is suited for the patient and procedure? As you can see, a lot of factors go into deciding which materials and techniques lead to successful repairs. Let's take a closer look at 3 of them.

1. Mesh choice
There are 3 synthetic materials used to make meshes, and each comes with its own benefits and drawbacks.

• Polypropylene meshes are non-absorbable, heavyweight options with small to medium pores. The heavy weight provides high tensile strength. The large mass of material activates profound tissue reaction and dense scarring which, in turn, can limit elasticity and can restrict abdominal distention. The smaller pores of heavyweight meshes lead to more shrinkage in the body due to the formation of scar plate. These meshes also produce dense adhesions, but have low infection risks.

• Polyester meshes are also non-absorbable, but with medium weight and large pores, features that allow increased soft tissue in-growth. These meshes are more elastic because they tend to avoid the granuloma bridging (a reaction to a foreign body) that leads to stiff scar plate and reduced flexibility. These meshes have a low infection risk and lower inflammatory responses than polypropylene meshes. However, polyester meshes degrade over the long term, perhaps the result of hydrolysis, which results in brittleness and loss of mechanical strength. Polyester meshes are less likely to cause seroma because of their large pores.

• ePTFE meshes are non-absorbable, heavyweight meshes with very small pores. This material isn't true mesh but rather a multilaminar patch. These patches are smooth and strong, but have a higher risk of infection due to their small pores, which macrophages, neutrophils, fibroblasts, blood vessels and collagen are unable to pass through. Bacteria that enter through the small pores can therefore survive unchallenged. On the other hand, ePTFE patches pose a low adhesion risk because they don't allow tissue ingrowth. For the same reason, however, they're unable to adhere strongly to the abdominal wall.

PATCH WORK Mesh fixation — with tacks or sutures — depends on the type of defect that needs repairing.

2. Defect type
Here are the various hernias your surgeons encounter, and effective approaches to fixing them.

• Hiatal hernias. I'm able to repair more than 98% of hiatal hernias without a mesh and in a tension-free manner. However, when a mesh is needed for reinforcement, I use an absorbable biosynthetic material composed partly of porcine small intestine submucosa. ePTFE meshes impregnated with antiseptic can be used for diaphragmatic hernias that cannot be approximated primarily.

• Incisional and ventral hernias. The majority of these hernias can be fixed primarily with bilateral flaps and component release as necessary to establish a tension-free repair. In cases where an underlay mesh technique is required due to a thin abdominal wall (that may also be denervated, devascularized and attenuated), a non-cross-linked bovine pericardium biologic can be used to reinforce the wall while limiting adhesion risks. However, during repair of complex hernias in which the fascial edges cannot be brought together even with bilateral flaps and component release, I'd use that same mesh with running sutures in a tension-free manner to join the flaps. Porcine biosynthetic intestinal, submucosal-derived mesh can sometimes be used for smaller abdominal hernias.

• Inguinal hernias. Almost all can be repaired laparoscopically. Polyester mesh, which has less foreign-body reaction, less seroma formation and, in my experience, causes less pain to patients, is preferred.

FAMILIAR FACES
Improve OR Efficiency

Surgeons prefer to work with their own, consistent team in the OR. The group that works with me on surgical days is very aware of which products I use for specific hernias — nobody has to leave the room searching for meshes or instruments — which saves time during procedures.

Surgeons should meet with their teams after each case to discuss what they did, which materials they used and what improved the procedure's safety and efficacy. Those informal meetings are also a time for the surgical team to bring up any concerns they have, and discuss possible solutions with the surgeon.

— Sharona B. Ross, MD

• Contami-nated hernias. Biomaterial products that are readily colonized by host tissue and that form scaffolding for repair and remodeling of the extracellular matrix should be used in these cases. The problem with these mesh types, however, is that they lose strength with remodeling. Non-cross-linked bovine pericardium biologic mesh seems to hold up best. As a side note, for fixation, it's best to use metallic tacks on inguinal hernias and sutures or a combination in laparoscopic (hiatal or incisional hernia) repairs. For open repairs, polypropylene running sutures are effective.

CHOOSE WISELY Surgeons weigh mesh options based on the patient's condition, hernia location and surgical approach.

3. Patient condition
When overweight patients arrive at my clinic with hiatal, abdominal or inguinal hernias, the first thing I'll usually ask them to do is work on weight loss because, for the best outcomes, they must reduce their intra-peritoneal pressure before surgery and for several months afterward. Athletic, active patients must know that, after the repair, they must avoid exercising abdominal muscles, which increases intra-peritoneal pressure and increases recurrence risk. Patients must also understand what factors into improved wound healing. Smokers should quit the habit and diabetics must learn how to maintain good blood sugar control leading up to and after surgery. The bottom line: Patients should understand how healthy lifestyles lead to improved healing.

COATED MESHES
Fewer Adhesions, Less Infection?

There are various types of composite meshes with coatings for intra-peritoneal use. First among them: ePTFE mesh, which comes impregnated with antiseptic to minimize infection. I sometimes use this mesh for diaphragmatic hernias.

One composite, partially absorbable, polyester mesh comes covered on 1 side with a bovine-collagen coating and anti-adhesion films of polyethylene glycol and glycerol. However, the anti-adhesion property is thought to be of short-term benefit. I occasionally use this mesh for incisional or abdominal wall hernias. My preference is always to fix these defects with primary repair — including component release — as necessary to achieve a tension-free hernia repair.

When the abdominal wall is too thin, denervated, devascularized or attenuated, however, I'd use the same material with an underlay mesh technique to reinforce the repair. The anti-adhesion film is then placed on the bowel side. For hernias that cannot be repaired primarily with bilateral flaps and component release, I'd use this mesh to bring the fascial edges together with running sutures and in a tension-free manner. Other coated meshes, such as polypropylene and sodium-based coated options, or polypropylene/omega-3 composite mesh, seem to have only short-term benefits. For example, the former's coating turns into gel in 48 hours; the gel remains on the mesh for 1 week to allow re-epithelialization.

— Sharona B. Ross, MD