The concept of vascular territories called angiosomes further elucidates our understanding of the blood supply to the abdominal wall skin. From a clinical perspective, preservation of the primary angiosome to an anatomic territory of skin maximizes blood flow to that territory. The primary central anterior abdominal wall angiosome is supplied by multiple cutaneous perforator branches of the deep epigastric artery system. Microdissection analysis of the vascular anatomy of the anterior abdominal wall skin and subcutaneous tissue has confirmed that perforator branches of the deep inferior epigastric vessels provide the main blood supply to this region. More specifically, the periumbilical region, mostly just inferior and lateral to the umbilicus is the region with the highest concentration of these perforator vessel branches (Fig. 9-1). The PUPS components separation technique focuses on maintaining this rich vascular network, thereby maximizing blood supply without compromising the degree of muscle flap advancement possible.

The conventional components separation (as described in Chapter 8) requires significant skin undermining and division of the periumbilical perforators and should be performed only if extensive subcutaneous skin flap elevation is necessary (i.e., as done during removal of an infected onlay synthetic mesh). Otherwise a periumbilical perforator sparing technique, performed open or laparoscopic should be attempted in all cases requiring components separation.

If dissection and removal of the hernia sac results in partial subcutaneous flap creation then one should continue that dissection around the periumbilical perforators and perform an open PUPS components separation. If there is no skin flap creation during removal of the hernia sac then a laparoscopic components separation can be performed (as described in Chapter 11).

Before surgery, the patient’s abdominal wall is marked. The hernia defect is outlined, and the locations of the periumbilical perforators are marked in reference to the rectus abdominis muscles (Fig. 9-4, B). The perforators are usually located within a 6 cm radius of the umbilicus but can be more laterally positioned in the presence of a large hernia sac.

All old incision lines are identified and marked. The planned skin incisions are marked, including any planned excisions of old scar and excess skin (Fig. 9-4 C).

The old scar and subcutaneous tissue posterior to the scar is excised. This is performed usually en bloc with the ventral hernia sac (Fig. 9-5, A). Care is taken during dissection of the ventral hernia sac not to undermine too widely from the sac in order to avoid injury to the periumbilical perforators. Once the dissection is completed to the edge of the fascial defect, the hernia sac is opened and excised (Fig. 9-5, B).

Assessment of fascial approximation is performed by placement of two or three Kocher clamps on each medial fascial edge (Fig. 9-5, C). If the fasciae can be easily approximated with minimal or physiologic tension then a components separation is not required. If the fascial edges do not approximate easily, then a components separation should be performed.

The PUPS components separation is now begun with creation of subcutaneous tunnels that will allow exposure of the anterior aspect of the external oblique fascia bilaterally (Fig. 9-6 and Fig. 9-7).

At the epigastric and suprapubic levels, using fiber optic lighted retraction, the skin and subcutaneous tissues are dissected off the anterior rectus sheath extending just lateral to the linea semilunaris. The epigastric tunnel typically exposes the costal margin and extends inferiorly from the xiphoid to a level 2 to 4 cm superior to the umbilicus (Fig. 9-8, A). The suprapubic tunnel typically exposes the inguinal ligament and extends superiorly from the pubic tubercle to a level 6 to 8 cm inferior to the umbilicus (Fig. 9-8, B).

Using a deep fiber optic lighted retractor or a headlight and deep Deaver retractor, these tunnels are connected from the top down and from the bottom up using cautery dissection. In this way, they can be joined together lateral to the linea semilunaris while avoiding injury to the periumbilical perforators (Fig. 9-8, C).

Exposure for division of the external oblique muscle fascia is through the epigastric and suprapubic tunnels. The rectus abdominis can be manually retracted medially and the aponeurosis of the external oblique muscle is divided with cautery in a longitudinal orientation approximately 2 cm lateral to the linea semilunaris (Fig. 9-8, C) (Fig. 9-9). Note that at this distance from the linea semilunaris, the external oblique is comprised of thin fascia inferiorly and thicker muscle superiorly.

The external oblique division can continue superiorly approximately 5 to 6 cm over the costal margin onto the thoracic ribcage and can extend inferiorly to the external inguinal ring if necessary (Fig. 9-9). Fiber optic lighted retraction allows maintenance of an optical cavity lateral to the linea semilunaris such that the periumbilical perforators are preserved during fascial incision.

Once the external oblique muscle is completely divided, it is then separated from the underlying internal oblique muscle in an avascular plane laterally toward the flank (Fig. 9-8, D).

If the posterior release is needed, the medial rectus abdominis edge can be retracted anteriorly and laterally with Kocher clamps, and the posterior rectus sheath can be incised longitudinally with cautery approximately 2 cm from the midline. From superior to inferior, this release can extend from under the costal margin to the arcuate line of Douglas where the posterior rectus sheath terminates (Figs. 9-10 and 9-11). Division of the posterior rectus sheath in this fashion typically yields another 1to 2 cm of release per side. Fascial approximation at the midline is again assessed.

Once the PUPS components separation has been completed, mesh placement is performed. The mesh is typically placed as an underlay in a retro-rectus or intraperitoneal location, whether a synthetic mesh or a biologic matrix is chosen, because the periumbilical perforators have been preserved (Fig. 9-12).

In placing the mesh as an underlay, the subcutaneous tunnels are used for placement of horizontal mattress transfascial sutures laterally to secure the mesh, thereby avoiding the periumbilical perforator vessels. The lateral sutures can be passed through the laterally displaced cut edge of the external oblique if the mesh underlay is wide enough. Otherwise, sutures can be placed through the medial cut edge of the external oblique at the linea semilunaris just lateral to the perforators (as noted in Fig 9-13 and 9-14). However, placement of sutures through the internal oblique and transversus abdominis muscles in the lateral subcutaneous tunnel can be performed to secure the underlay mesh as well. The mesh can be sutured with permanent or long-lasting absorbable sutures.

Before fascial closure, a drain should be placed anterior to the mesh to minimize the incidence of subfascial fluid accumulation (see Figs. 9-12 and 9-13, A). This fluid could otherwise be a source of postoperative discomfort or infection, and it can be a barrier preventing apposition of the mesh to the rectus muscle, thereby preventing early fibroblast and vascular ingrowth and incorporation.

A “double lay” mesh placement, combining both an underlay and onlay mesh, can be performed in cases of biologic matrix implantation in an attempt to minimize the chance of hernia recurrence (Fig. 9-14). A 4- to 6-cm wide segment of mesh is cut from the lateral side of the original piece. The underlay component is sutured in with at least a 5- to 7-cm underlayment; a drain is placed anterior to the underlay mesh, and the fascia is closed primarily over the drain. The onlay mesh piece is “pie-crusted” before implantation to avoid seroma entrapment between the anterior rectus sheath and the onlay mesh. The onlay portion of the double lay matrix may need to be “hour-glassed” at the level of the periumbilical perforators in order to preserve them. The onlay mesh can be sutured along its perimeter with a running long-lasting absorbable or permanent suture.

Midline fascial closure is performed following completion of the underlay mesh placement (see Fig. 9-13, B). If the fasciae approximate with some tension, an interrupted figure of eight closure is used. This can be performed from the top down and from the bottom up until the point of maximal tension is closed. If the fascial edges approximate easily, a running closure can be performed.

There are three subcutaneous compartments following a PUPS components separation. There is a right lateral, a left lateral, and a central abdominal subcutaneous compartment. Each of these compartments should have a subcutaneous drain. Therefore, each patient would have three subcutaneous drains and one subfascial drain (Fig. 9-15).

Midline abdominal wall closure includes the placement of interrupted absorbable sutures for approximation of Scarpa fascia, as well as a deep dermal repair. The skin closure can be performed with staples or with absorbable subcuticular sutures covered by a liquid epidermal bonding agent (Fig. 9-13, D and Fig. 9-16).

Patients with obesity or with a history of massive weight loss may benefit from simultaneous panniculectomy in the setting of ventral incisional hernia repair (Fig. 9-19, A).

The PUPS approach to components separation allows safe simultaneous panniculectomy. The hernia defect is approached through the previous midline incision. The external oblique fascial incision lateral to the linea semilunaris can then be approached through a longitudinal subcutaneous tunnel created following the panniculectomy (Figs. 9-19, B and 9-20). With fiber optic lighted retraction, dissection with incision of the external obliques can extend several centimeters superior to the costal margin through this approach.

The upper abdominal medial subcutaneous attachments maintain the periumbilical perforator blood supply to the remaining skin, which is closed vertically and transversely (Fig. 9-19, C).