Ventral hernias, a common complication in nearly 10% of all open abdominal surgeries, occur when abdominal tissue or organs protrude through a gap between the muscles of the abdominal wall ( 1 ). Of the 350,000 to 500,000 ventral hernia repairs performed each year in the US, significant amount are complicated by loss of domain, making the procedure both difficult for the surgeon and dangerous for the patient ( 2 ). Often seen in patients who have undergone previous abdominal surgeries, ventral hernias are characterized by large bulges in the abdominal or groin areas ( 3 ). Giant ventral hernias, which occur when the gap in the abdominal wall grows beyond ten centimeters, can pose considerable surgical risk to the patient. If left untreated, giant ventral hernias can proceed to fill the abdominal cavity, hindering blood supply to the intestines and causing them to deteriorate. Common methods in ventral hernia repair include minimally-invasive laparoscopic surgery, open surgery, or the insertion of a single wire mesh to keep the tissue in place.
A serious problem in ventral hernia repair often occurs when patients present with loss of domain. “When patients have loss of domain, their abdominal wall essentially has a hole in it and a lot of the intra-abdominal contents are outside of the abdominal wall,” says Dr. Faris Azar, a surgical resident at Johns Hopkins Hospital. In cases of patients with loss of domain, the abdominal cavity is not able to accommodate the contents of the abdomen within the boundaries of the abdominal fascia, the layer of connective tissue that lines most of the abdominal cavity. As a result, a significant amount of viscera is forced through a large opening in the abdominal fascia to reside on the outside of the abdominal cavity. “To repair this,” notes Azar, “the abdominal wall fascia must be brought together and this is what makes the operation very difficult.” Furthermore, since “those with loss of domain usually require a big open operation and have usually had multiple operations in the past,” he continues, they present with “a hostile abdomen with a lot of scar tissue bands that are not amenable to laparoscopic surgery.” Closure of the abdominal fascia is thus often impossible with current methods, and even when successful can lead to complications such as high intra-abdominal pressures, abdominal hypertension, and abdominal compartment syndrome ( 4 ). In some cases, closure of the fascia can even lead to a severe condition known as fascial dehiscence, a sudden bursting of the abdomen that has been associated with mortality rates as high as 45% ( 5 ). A recent study carried out by Dr. Azar and fellow Johns Hopkins surgeons may soon redefine how surgeons approach the repair of ventral hernias that are complicated by loss of domain. A report on the study was published in the February 2017 issue of the journal Hernia ( 6 ). Over the nine-year study period, twenty-one cases of patients who underwent ventral hernia repair complicated by loss of domain were reviewed. Of the twenty-one cases, some of which involved the repair of giant ventral hernias, surgeons utilized a “sandwich” method in seventeen of them as an alternative to simply sewing shut the opening in the fascia. “The sandwich method,” says Azar, “is a preferred method used at Hopkins whereby a biologic mesh is placed inside the abdomen,” after which “the fascia [is] closed overtop and then a synthetic mesh [is] placed over that.” The biologic mesh placed beneath the gap in the abdominal fascia serves the dual purpose of stimulating regrowth of the fascia and reducing the risk of foreign-material-associated infection. The synthetic mesh that is later placed above the fascia serves to reinforce the abdominal wall and prevent conditions such as fascial dehiscence from occurring. Surgeons attach the biologic and synthetic meshes to the underside and top of the fascia, respectively, using permanent sutures and fibrin sealant. In order to carry out a tension-free repair as to prevent ruptures along the incision site, the sutures are placed equidistant to each other so that no one suture experiences more tension than another.
Following their surgeries, the patients returned monthly to the Johns Hopkins Hospital over the course of the next year for a clinical assessment of their postoperative conditions. Notably, the sandwich method was shown to provide a protective effect against the recurrence of ventral hernias. The study found that when the sandwich method was utilized, ventral hernia repairs in patients with loss of domain could be performed with low recurrence rates and minimal morbidity. Of the twenty-one patients with loss of domain who underwent ventral hernia repair, there were no mortalities, and only two (10%) experienced hernia recurrence, a number in marked difference with the recurrence rates of up to 67% that has previously been associated with ventral hernias complicated by loss of domain ( 7 ). Infections of the surgical site were also few and far in between, likely due to the insertion of biological, rather than synthetic, mesh beneath the fascia.
Looking forward, the surgical team notes that while the study affirms that the repair of ventral hernias with loss of domain can be performed with low recurrence rates and infectious complications through the use of the sandwich method, additional studies are needed to better understand the long-term effects of this procedure. The successful results obtained from using the sandwich method, however, provide a positive outlook for further reducing complication and recurrence in ventral hernia repair in the future.
Other authors on the paper are T.C. Crawford, K.E. Poruk, N. Farrow, P. Cornell, O. Nadra, S.C. Azoury, K.C. Soares, C.M. Cooney, and F.E. Eckhauser.