1. Field of the Invention
This invention relates to generally to surgical devices, and more particularly relates to mesh surgical devices for hernia repair.
2. Description of the Prior Art
The layer or layers of fascia that lie in the abdominal wall and surround the peritoneal cavity are the strong structures that maintain the integrity of the peritoneal cavity. If there is a defect in the fascia, abdominal contents may penetrate through the weaker layers of the abdominal wall (comprised of muscle or fat) and push ahead or through the thin lining (peritoneum) of the abdominal cavity so that the abdominal contents, such as omentum or bowel and become trapped.
The squeezing of viscera through a facial defect can cause pain. When a visceral structure becomes trapped outside the fascial plane, it is incarcerated. Incarcerated viscera can be strangulated by a narrow facial defect, producing ischemic necrosis. This may lead to toxemia, infection, bacteremia and death if not surgically repaired. It is therefore preferable that hernia be repaired early, prior to becoming incarcerated or strangulated.
In modern practice, hernia repair is often accomplished by implanting a surgical prosthesis, such as a hernia patch (or mesh), over a fascial defect. The patch is fixed to the surrounding tissue with sutures or fasteners. The hernia patch prevents the herniation of the abdominal viscera through a defect in the fascial layer. This technique is preferred over direct suture closure of the fascial defect, as it avoids the exertion of excessive tension on the musculofascial tissue and thereby makes it less likely for the hernia to recur. Hernia repair with prosthetic patches can be accomplished via an open or laparoscopic approach.
The mesh or patch used for hernia repair can be in direct contact with the structures in the abdominal cavity, for example, the intestines, so that there is a tendency for adhesions to form in between these structures. Such adhesions are known to be responsible for certain occasionally serious complications.
Many conventional hernia patches are made of a thin, flexible material. The limited visibility and maneuverability available to the surgeon, and the fact that many hernia patches tend to become folded, stretched or gathered when being positioned, may lead to disorientation and improper placement and/or fixation of a hernia patch. This may result in a failure to cover the entire hernia defect, or improper tension on the patch. Such errors may result in the recurrence of the hernia.
Another problem with conventional hernia repair devices is that, once applied, they can entrap the intestines or omentum between the tissue where the repair device is applied and the device itself.
Some commercially available devices have stiffening elements at the edge of the device coupled with straps placed in the middle of the device. Upon pulling the straps, the outer edge of the device is brought in proximity to the peritoneum. Other approaches have been to repair the hernia via a pre-peritoneal approach, thereby avoiding the issue of entrapment altogether. The problem with the first design has been that it can buckle if the straps are pulled too hard. Also, if the stiffening element was made from a bioabsorbable material, it would degrade and lose its stiffness prematurely, possibly causing the intestines to become entrapped between the device and the peritoneum. The issue with the second approach is that it necessitates the creation of a space to insert the device thereby forming a potential “dead space” where a seroma may form. This approach requires a greater level of skill to implement and has the potential of perforating the peritoneum.
Attaching adhesion barriers to the part of the device that faces the abdominal content is another approach. This prevents adhesion of the intestines to the visceral side of the device, but does not prevent intestinal entrapment between the device and the peritoneum. Indeed, it is preferable that the side of the device that faces the peritoneum (in devices that are implanted intraperitoneally) is made from a material that encourages tissue integration. This, in turn, carries the risk that if the intestines or omentum is entrapped between the device and the peritoneum, the entrapped tissue will integrate firmly with the device.
Some conventional hernia repair devices require the surgeon to anchor the device to the peritoneum or pre-peritoneal tissue layers by sutures that are placed blindly. More specifically, the suture needle in accordance with this procedure is inserted through the muscular layer and the fascia to anchor the hernia repair device, and is then returned through the fascia and muscular layers. This blind technique to anchor the repair device carries the risk of injuring underlying tissues, such as the intestines, liver, spleen and vasculature.
A “suture-passer” device has been employed to facilitate the fixation of the hernia repair device to the peritoneum with sutures. Grasping and feeding of the suture into the grasping arm of the “suture passer” within the abdomen and fixation or suturing of the mesh to the abdominal wall are technically difficult, cumbersome and time consuming.
U.S. Patent Publication No. 2001/0044637, having Daniel Jacobs and Robert James Elson as named inventors, discloses tension systems with barbs which are stated to be capable of holding tissues together. The problem with using such a tensioning system is that the insertion of barbs into the abdomen carries the risk of injuring the abdominal contents. It is only when the contact with the peritoneum is complete, without any obstructions, that such barbs are of potential benefit. If the barbs come in contact with any abdominal organs, the risk of injuring such organs is significant, as these organs are typically fragile. Moreover, even superficial injury to abdominal contents will increase the risk of adhesions of an organ to another.