Component sepration techniques.pptx

component sepration techniques for ventral hernias and relevant surgical anatomy

1. Component separation techniques By Dr amber khare

2. Anatomy of abdominal wall Laterally, the abdominal wall is constructed of three layered flat muscles. From superficial to deep these are the external oblique , internal oblique and transversus abdominis muscles. The transversalis fascia is the deepest layer of fascia in the abdominal wall and separates the transversus abdominis muscle from the peritoneum.

3. The EO muscle runs inferior-medially, originating at the lower costal margin and inserting at the linea alba, iliac crest, and pubic tubercle

4. The IO muscle runs perpendicular to the EO with its origination at the lateral half of the inguinal ligament, anterior iliac spine, and thoracolumbar fascia and inserting into the lower ribs and linea alba.

5. Each muscle body is surrounded by its relevant fascia and these laminal layers join to form aponeurotic connections for each flat muscle. Medially the three aponeuroses form the linea semilunaris, which lies at the lateral edge of the rectus abdominis muscle .

6. The rectus abdominis is a vertically oriented muscle originating at the pubic symphysis and inserting into the fifth to seventh costal cartilages .

7. The EO aponeurosis and anterior lamina of the IO aponeurosis fuse to form the anterior rectus sheath

8. While the posterior lamina of the IO overlies the transversus abdominis muscle body. The transversus abdominis muscle extends medially in the upper abdomen, just deep to the rectus muscle, and the posterior lamina eventually joins the transversus abdominis aponeurosis to form the posterior rectus sheath. In the middle third of the abdomen, the transversus abdominis muscle ends more laterally and the posterior rectus sheath is formed by the aponeurosis of the transversus abdominis and the posterior lamina of the IO aponeurosis. In the lower third of the abdomen, below the arcuate line, the IO and transversus abdominis aponeurosis fuse with the EO aponeurosis as part of the anterior rectus fascia, leaving only peritoneum deep to the rectus abdominis

9. Medial to the body of the rectus abdominis muscle, all of the flat muscle aponeuroses fuse to create the linea alba and the midline of the anterior abdominal wall The spigelian fascia is a fusion of the IO and transversus abdominis aponeurosis that lies between the semilunar line and the lateral edge of the rectus abdominis muscle body. The spigelian fascia is weak inferior to the umbilicus as the aponeuroses of IO and TAMs run parallel in this location, so there is minimal crosslinking for strength. .

10. The vascular supply of the rectus abdominis enters the muscles laterally via branches of the inferior and superior epigastric arteries. The rectus abdominis is innervated segmentally via the thoracoabdominal (T7 to T11) nerves that also enter the muscle body at the lateral edge, just medial to the linea semilunaris. The vascular supply for the flat muscles of the abdomen are branches of intercostal arteries that run with thoracoabdominal nerves in the neurovascular space between the IO and transversus abdominis muscles. The skin and subcutaneous tissue of the anterior abdominal wall gets its blood supply from deep perforators that branch from the deep inferior and superior epigastric vessels

11. MESH LOCATION

12. Intraperitoneal placement is performed easily but suffers from high rates of mesh migration, and due to decreased tissue ingrowth, higher mesh infection rates. Preperitoneal and retrorectus positioning benefits from the increased vascularity of their respective spaces, as well as decreased fixation requirement, but requires more dissection to perform

13. “Separation of components” was first described by Ramirez in 1990 as a method for increasing laxity of the abdominal fascia to achieve tension-free midline closure Many complex and often multiply recurrent incisional hernias are not amenable to basic repairs or traditional laparoscopic techniques. Those patients frequently need more advanced reconstructive procedures to address their defects in order to provide a durable and functional repair. These patients require abdominal release or component separation procedures to provide for excessive-tension-free closure and reduce the risk of recurrence. ABDOMINAL RELEASE PROCEDURES

14. Component separations include a variety of techniques wherein the layers of the abdominal wall are strategically divided and separated for the purpose of medialization of the rectus muscles and restoration of the linea alba. In other words, the redundancy of layers of anterior and lateral abdominal walls allows for sacrifice of one or several of its components to provide for myofasciocutaneous medialization aimed at restoring near-normal anatomy and physiology to the entire abdominal wall

15. PreOperative Preparation The patient must be free of active infections, especially in the skin. Respiratory function should be optimized with cessation of smoking and appropriate pulmonary function evaluation. If bowel is contained with the hernia, endoscopic visualization, contrast studies, or imaging may be performed preoperatively and the patient may be given a bowel preparation with a liquid diet and cathartics for 1 or 2 days prior to surgery. The major factors in the occurrence of this hernia, as well as the preceding operative note(s), should be reviewed. Anesthesia General anesthesia with an endotracheal tube is required. Position The patient is placed in a supine position with a pillow placed to produce mild flexion of the hips and knees. This helps to relax the abdominal wall and take some tension of off any repair performed

16. Incision and exposure A component separation technique is most effectively utilized for midline abdominal hernias Typically a midline abdominal incision is made overlying the hernia . The incision may extend from the xiphoid to the pubis or be shorter and tailored to the size of the defect undergoing repair. teardrop or elliptical incisions to excise attenuated skin and scar tissue

17. ANTERIOR COMPONENT SEPARATION Operative Technique Once the abdomen is entered, a safe and complete adhesiolysis between the viscera and abdominal wall should be performed. The anterior fascia is identified and secured The skin and soft tissue are released from the anterior rectus fascia using electrocautery.

18. The plane between the anterior fascia and the subcutaneous tissues is then incised and large lipocutaneous flaps are developed These flaps are raised from the costal margin to the inguinal ligament and laterally to the midclavicular or anterior axillary line

19. This is continued lateral to the rectus sheath. The lateral border of the rectus sheath is then manually identified and a superficial fascial incision is made 1 to 2 cm lateral to the rectus sheath(semilunar line) This incision should only divide the external oblique aponeurosis

20. Incision is extended In a vertical fashion from the costal margin to just above the inguinal ligament. It is crucial to properly identify and protect the semilunar line. If this incision is made lateral enough to expose the muscle fibers of the EO, then the muscle fibers are divided using electrocautery

21. Once the EO complex is divided, the EO muscle should be “separated” laterally from the underlying IO aponeurosis using blunt dissection along the avascular plane

22. If this release does not allow for sufficient medial advancement, a posterior rectus sheath release can also be performed. Once adequate release has been performed, mesh placement can be completed. The choice may depend on wound class, comorbidities, and other factors. Mesh positioning is done as per the choice surgeon The mesh can be placed as an intraperitoneal underlay, as a sublay in the posterior rectus space, or as an onlay above the anterior rectus fascia

23. Intraperitoneal mesh must be secured with circumferential transfascial sutures along the edge of the mesh, closing the space to abdominal contents. Onlay mesh is placed after re-creation of the linea alba and is secured to the cut edges of the EO aponeurosis. Fibrin glue has also been used as an adjunct in mesh fixation for onlay meshes. Large-bore closed-suction drains should be left ventral to the mesh, regardless of its position within the abdominal wall

24. Midline fascial closure should be completed with absorbable monofilament suture either in a running fashion or using interrupted figure-of-eight sutures to achieve reconstruction of the linea alba and approximation of the rectus abdominis muscles. Soft tissue closure after ACS is of great importance because subcutaneous flaps can be a source of major wound and mesh morbidity. Dead space between subcutaneous tissue and fascia or mesh must be dealt with to avoid seroma and hematoma formation. This can be achieved with closed-suction drains or suturing the soft tissue back down to the fascia with progressive tension suture technique. Any old scars, as well as ischemic or devascularized , attenuated and redundant skin and soft tissue must be excised Closure of skin

25. With the anterior component separation, the surgeon can achieve up to 10 cm of fascial advancement on each side. However, the creation of large lipocutaneous flaps does predispose the patient to wound complications such as seroma, abscess, and skin necrosis. Most centers consider active tobacco use an absolute contraindication, and most require a hemoglobin A1c less than 7

26. PERIUMBILICAL PERFORATOR-SPARING ANTERIOR COMPONENT SEPARATION The skin of the central abdominal wall gets its blood supply from the deep inferior and superior epigastric vessels. The deep epigastric vessels divide into a vast network of musculocutaneous perforating branches and are concentrated in the periumbilical region to provide the majority of vascularity to the central abdominal wall. Therefore, to combat the significant wound morbidity caused by the creation of the necessary large undermined subcutaneous flaps, Dumanian was first to develop a perforator-sparing component separation technique. The goal is to maintain pulsatile blood flow to the reapproximated tissue of the hernia repair and to release lateral tension at the midline. Wound complications have been found to be reduced by 50% to 90% with techniques that allow for preservation of the periumbilical perforators of the abdominal wall.

27. Perforator-sparing ACS can be completed via lateral incisions or via tunneling from the midline at the inferior and superior portions of the laparotomy incision . The EO fascia is incised and the EO muscle is bluntly separated from the underlying IO fascia. A tunnel in this plane is developed bluntly with finger dissection and the aid of a lighted retractor for the length of the abdomen, spanning from inferior to the inguinal ligament to superior to the costal margin

28. Superior and inferior such tunnels can be created until they meet in the middle lateral to the semilunar line, thus sparing the periumbilical perforators of the soft tissue dissection. Within this tunnel the EO fascia and muscles are divided and bluntly separated from the underlying IO fascia. Once the release is completed, the tunnels can be closed or drained and the hernia is repaired with mesh in the intraperitoneal underlay or retrorectus dissection.

29. Retro rectus repair The French surgeons Jean Rives and Rene Stoppa revolutionized hernia repair by popularizing a retrorectus repair with a large prosthetic mesh in the 1960s The prosthetic is placed in the preperitoneal space below the arcuate line or just superficial to the posterior rectus sheath above the umbilicus

30. Repair benefitted from a two-layer fascia closure as well as placement of the prosthesis within the highly vascular retrorectus space, which promotes more robust tissue ingrown in the mesh and protection from infection The abdomen is entered in a similar fashion as for the onlay technique. The medial edge of the rectus sheath is identified and incised, and this incision is extended along the length of the hernia defect

31. The rectus abdominis muscle should then be easily identified and its fibers bluntly swept anteriorly. This plane should be developed laterally to the lateral border of the rectus sheath, taking care not to injure the neurovascular bundles penetrating the muscle Once this dissection is completed on both sides of the defect, the two sides are connected in the upper and lower midline The posterior fascia can then be closed using a running absorbable suture.

32. An uncoated medium-weight mesh is then selected and sized to fit on top of the posterior closure. Although no fixation is absolutely necessary, if such fixation is desired, transfascial nonabsorbable sutures can be secured to the mesh and brought through the anterior sheath. Once the mesh is in place, the anterior sheath is then closed using either permanent or slowly-absorbing suture

33. POSTERIOR COMPONENT SEPARATION The posterior component separation, or transversus abdominis release (TAR), was developed by Yuri Novitsky and Michael Rosen as a solution to the wound morbidity and mesh limitations of the anterior component technique The technique creates an “extension” of the retrorectus plane developed in the Rives– Stoppa repair, allowing for mesh placement posterolateral to the psoas muscle as well as creating fascial advancement by releasing the attachment of the transversus abdominis muscle

34. TRANSVERSUS ABDOMINIS RELEASE The TAR technique has been shown to be durable and reliable in a number of series with recurrence rates between 3.7% and 5%. It has also been found to be safe and effective for repairing recurrent ventral incisional hernias following ACS. TAR allows access to the space above the xiphoid and costal margins, aiding in repair of complex subcostal and subxiphoid hernias

35. Operative Technique A full laparotomy incision is made and adhesiolysis is carried out as needed. The posterior rectus release begins with the incision of the posterior rectus sheath at its most medial border, confirming the location of the rectus muscle ventral to the initial incision. This incision is taken along the full length of the rectus muscle, cranially to the xiphoid and caudally to the arcuate line and into the space of Retzius . The posterior sheath is dissected free from the rectus abdominus muscle medially to laterally using blunt dissection and electrocautery. This is a mostly avascular plane until the lateral edge of the rectus muscle is reached and deep perforating vessels are encountered.

36. As the lateral edge is reached, the epigastric vessels can be visualized and should remain with the muscle body. The dissection is complete when the semilunar line has been reached. It is important to identify neurovascular bundles as they perforate the posterior rectus sheath just medial to the linea semilunaris.

37. Superiorly this dissection leads into the subxiphoid space and the insertions of posterior sheath at the xiphoid can be incised to allow access into this plane across the midline. Inferiorly, the dissection leads into the space of Retzius ; blunt dissection is performed to skeletonize the pubic symphysis and bilateral Cooper ligaments

38. Exposure and division of the transversus abdominis muscle (TAM) is begun by the incision of the posterior sheath 1 cm medial to the perforating vessels, as cephalad as possible. This incision exposes the muscular aspect of the TAM in the superior portion of the abdomen and the aponeurotic aspect in the inferior portion.

39. The TAM fibers are then divided with electrocautery, using a right-angled dissector to isolate and lift the fibers from the underlying transversalis fascia and/ or peritoneum. This division is completed cranial-caudally until there is complete transection of the TAM and its aponeurosis. At the level of the arcuate line, the surgeon must make a transition into the preperitoneal space and divide the arcuate line laterally at its junction with the semilunar line

40. Once this plane is created, it can be continued laterally using blunt dissection until the psoas muscle is identified, if necessary. Dissection following the lateral edge of the psoas muscle caudally. In women, round ligaments are divided. In men, spermatic cord should be identified and protected The superior dissection is now undertaken, and depending on the location of the hernia, the cranial extent of the dissection may be in the epigastrium or the subxiphoid space

41. The next step is to reconnect medialized posterior layers and to re-create a continuous visceral sac with running absorbable sutures. Any small holes in the posterior layer may be closed with figure-of-eight or interrupted absorbable sutures, and any larger gaps in the posterior layer can be filled with an interposition of polyglactin or biologic mesh. Once the posterior sheath is closed, the abdominal contents are now excluded from the operative space.

42. Generous irrigation of the retromuscular space is completed. We can use antibiotic-laden irrigation (cephazolin 3 g, gentamicin 240 mg, Bacitracin 50,000 units per 3 L of normal saline) with a power irrigator in contaminated or clean-contaminated cases A mesh is then measured to fill the entire retromuscular space. We generally favor a midweight macroporous polypropylene mesh in most of case Fixation of the mesh is done with long-lasting absorbable sutures to bilateral Cooper ligaments and transfascial sutures at the xiphoid. Lateral transfascial fixation can be done Large closed-suction drains are placed ventral to the mesh and brought out laterally through the abdominal wall. The anterior fascia is closed with running or interrupted figure-of-eight sutures, and the skin and soft tissue are closed in layers after excision of any excess tissue

43. Component separations should be used for select patients only and indications for the procedure should be part of an algorithm for treatment of complex abdominal wall hernias.

44. Thank you