Vessels Of The Abdominal Wall

The vessels of the abdominal wall can be divided into two types- superficial vessels and deep vessels.

Superficial Vessels

The superficial vessels originate from the branches of the femoral vessels and deliver blood to the anterior wall of the abdominal wall. The skin and subcutaneous tissue are supplied by them. The superficial circumflex iliac vessels (which supply the anterior superior iliac spine, or ASIS), the superficial epigastric artery, and the superficial external pudendal vessels (which supply the mons pubis) are among the femoral vessels' branches. The transverse incision in the anterior wall displays the superficial epigastric vessels.

Deeper Vessels

These serve the musculofacial layer and are the branches of the external iliac vessels. Located in the neurovascular plane between the transversus abdominis and the internal oblique muscles, the first branch is a deep circumflex iliac artery.

It advances in the direction of the anterior superior iliac spice. The inferior epigastric artery, which arises from the external iliac artery at a deeper level, is the second branch. It ascends through the transversalis fascia in the direction of the umbilicus before anastomosing with the matching superficial epigastric artery. The transversalis fascia is where the inferior epigastric artery is seen.

The former lies behind the rectus muscle and punctures the transversalis fascia at a point close to the muscle's lateral border. The rectus muscle receives blood flow from this artery as well. Injury to the inferior epigastric artery might result from any transverse incision made on the rectus muscle.

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Surface Anatomy Of These Blood Vessels

 The lower abdomen's superior and inferior epigastric vessels are positioned farther apart than those in the upper abdomen. Therefore, it is preferable to make lower abdomen incisions to prevent running into these issues when making transverse incisions.

These vessels are positioned 4.5 cm (about) apart at the level of the umbilicus and 5.5 cm (roughly) to the midline above the pubis symphysis.  It is important to understand these anatomical placements because it is important to prevent disrupting and harming the superficial gastric artery when installing lateral laparoscopic trocars to establish ports.

A hematoma may form as a result of this rupture, which may cause bleeding inside the fascial layers that is first undetected. Placing the trocars laterally and medially in accordance with these anatomical features is therefore a safer method.

 It's important to keep in mind that the superficial epigastric artery is visible from the medial to the round ligament, inside the peritoneal cavity. Trocars must therefore be used with a goal for safe surgery in mind.

Applied Anatomy

When making a surgical incision, the anatomy is extremely important because if it is not, there is a risk of bleeding and hematomas from these veins.  Transverse muscle cutting incisions (rectus abdominis muscles) can cause damage to the inferior epigastric artery.

While placing lateral laparoscopic trocars, it is crucial to understand the architecture of the vessels. There is a higher risk of injury to the inferior epigastric artery if the low transverse incision extends beyond the lateral margins of the rectus muscle.

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Nerve Supply To Abdominal Wall

The patient frequently reports tingling and irritation in the afflicted area following the modest transverse incision on the anterior wall of the abdominal wall. The anterior abdomen's disrupted cutaneous nerve supply is the cause of this. This is a common, inevitable ailment that normally gets better with time.

This area is primarily supplied by the following nerves:  Intercostal nerve (T7 to T11), Subcostal nerve (T12) These comprise the spinal nerves' anterior rami. The lumbar plexus is made up of the o iliohypogastric nerve, o ilioinguinal nerve, and o iliohypogastric nerve.

Intercoastal Nerve

The neurovascular plane, which is situated between the transverse abdominis muscle and the internal oblique muscle, is traversed by the intercostal nerves. They supply the skin above after penetrating the rectus sheath that surrounds the lateral border of the rectus muscle. A transverse incision that penetrates the rectus muscle's lateral border may cause damage to the anterior cutaneous division of the intercostal nerves. The cutaneous nerves may become strained or torn when the anterior rectal sheath is separated from the rectal muscle. This is the main cause of the patient's reported tingling feeling following Pfannensteil surgery.

Applied Anatomy

Denervation atrophy of the muscle and weakening of the abdominal wall may result from incisions made along the lateral border of the rectus.  During transverse incisions, lifting the rectus sheath of the muscle may stretch the perforating nerves, causing a localized area of cutaneous numbness.

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Ilio-Inguinal And Ilio-Hypogastric Nerve

The ilioinguinal nerve passes via the inguinal canal. These are the branches of the lumbar plexus.These two nerves exclusively move in the neurovascular plane when they pass medially through the anterior superior iliac spine.

The ilioinguinal nerve reaches the inguinal canal independently rather than via the deep inguinal ring. It enters the inguinal canal after piercing internal oblique muscle fibers. The skin of the mons pubis, upper labia majora, and the top side of the medial thigh are innervated by both of these sensory nerves.

The iliohypogastric nerve perforates the external and internal oblique muscles in the vicinity of the lateral rectus margin. It provides nourishment to the skin located above the pubis.

These nerves can be injured by a low anterior transverse incision on the lateral rectus margin. They can also become entrapped during the process of sealing the rectus or while receiving hemostatic sutures to halt vascular bleeding.

Applied Anatomy

The low transverse incision should not extend beyond the lateral margins of the rectus;  Lateral laparoscopic trocars should be placed superior to the ASIS;  The ilioinguinal and iliohypogastric nerves can be cut or entrapped during low transverse incisions or placement of laparoscopic trocars in the lower abdomen, which can lead to chronic pain syndromes or cutaneous anesthesia.

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Abdominal Incisions

Vertical Midline Incision

The incision is made vertically midline. The anterior and posterior rectal sheaths are accessible by cutting apart the skin and subcutaneous tissue. The visceral peritoneum and the transversalis fascia are then accessible. It offers:

• Quick access to the abdominal cavity.
• The linea albia, or midline, is the least bleeding.
• It offers superior exposure.
• It is simple to stretch upward.
• It results in very little nerve injury.
• This incision heals slowly because of its low vascular.
• More hernias and wound dehiscences have been documented.

A vertical incision below the arcuate line creates an aperture to reveal all three aponeurosis layers. A separate incision must be made to reach the posterior rectal sheath, though, if the incision is extended upward over the arcuate line.

Transverse Incision

 It was thought to take a lot of time. However, proficiency is attained by regular clinical practice.  The cosmesis is superior.

Compared to a vertical incision, it is stronger.  It causes less discomfort and interferes less with breathing after surgery.

The bleeding might be greater than with vertical incisions.

The division of cutaneous nerves may result from it. Because it includes several layers of fascia, hematomas could occur. Infections can result from hematomas. It offers restricted exposure, particularly in the upper abdomen.

Pfannenstiel Incision

The incision is 10–15 cm long and gently curved. It is slightly upwardly concave, ending just above the pubic symphysis.

Certain perforating nerves may be stretched when raising the rectus muscle and splitting the rectus sheath. Making sure the rectus muscle is not lifted higher than is necessary may help avoid this.

It is necessary to split the rectus muscle, not cut it off from the midline.  The peritoneum is removed vertically; The ilio-inguinal and ilio-hypoglossal nerves may become entrapped if the rectal sheath incision is continued laterally into the flesh of the external and internal oblique muscles.

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Kustner Incision

Compared to Pfannensteil incision, this approach was designed to offer greater exposure and greater tensile strength than vertical incision. This incision is placed below the level of the pubic hairline and the ASIS, with a gentle curvature.

It has limited extensivity in comparison to vertical incision;  It is a vertical incision in the rectus sheath along the linea alba;  It has little to no advantage in tensile strength over the Pfannensteil incision.

Cherney Incision 

During surgery, if additional exposure is needed, the Pffannensteil incision can be expanded into the Cherney's incision.  It is distinct from the muscle-cutting incision (Maylard incision) and offers greater exposure to the lateral pelvic wall region and the space of Retzius behind the bladder.

The rectus muscle is released from its tendonous insertion during this incision, and the lower flap of the rectal sheath is used for reattachment.

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Maylard Incision

To create a muscle-cutting incision, the rectus abdominis muscle is transected in this procedure.  It is carried out in the wall of the lower abdomen.  It is carried out in front of the arcuate line. Laterally, the inferior epigastric vessels are seen.

Make sure the rectus sheath or aponeurosis is not separated individually; ligate the inferior epigastric arteries to prevent bleeding.  Compared to the Pffanensteil incision, it exposes more tissue, but it also necessitates more specific care when it comes to ligating and separating the inferior epigastric arteries. Maylard's incision is frequently inferior to Cherney's incision.

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