Surgical Access Incisions
Introduction
A well-planned surgical incision is one of the most crucial steps in any surgical procedure. It is always essential to determine the proper location of the incision for optimal visualization and to always keep in mind anatomy, and blood supply that may suffer compromise. Exact placement and size of the incision utilized are also crucial for aesthetical reasons. If it is a small procedure that requires only minimal entrance into the abdomen, then smaller more strategically placed incisions are the best choice. However, if there is massive trauma, a large organ to be removed, or the surgery is exploratory, then a larger incision may be performed to gain the most exposure possible. This article will explore different types of incisions, indications for each, as well as important anatomical considerations.
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Function
The anterior abdominal wall contains several muscle layers, fascial layers, and vessels. The midline of the abdomen is where the rectus abdominis is with the linea alba (an avascular fascial plane) dividing the rectus into two sides. The lateral abdominal wall consists of the external and internal oblique muscles, and the transversus abdominis. The blood supply to the anterior abdominal wall consists of the inferior epigastric, the superficial inferior epigastric, the superior epigastric, branches of the internal mammary arteries, and the perforating branches of the obliques. Between each muscle layer is a designated facial layer to provide support and structure to the musculature.
Issues of Concern
TYPES OF INCISIONS
Midline Incisions
Also known as the laparotomy incision, or celiotomy, this is the most traditional of surgical incisions. It may be variably sized depending on the type of procedure performed. Midline incisions may be small and applied anywhere on the vertical linea alba. However, they can also extend from the xiphoid process to the pubic bone. This location is a mostly avascular plane and does not impose a great risk to the blood supply. There is rarely nerve damage in this region. However, scarring will be present and may be significant if performing multiple operations through the same incisional scar. This incision generally provides the best visualization and intra-abdominal access and is commonly used for exploratory procedures and traumas.
Kocher Incisions (Subcostal)
The Kocher incision is a subcostal incision on the right side of the abdomen used for open exposure of the gallbladder and biliary tree. This incision is just inferior and parallel to the subcostal margin. Unlike the midline incision, it is not an avascular plane. The incision extends through the anterior rectus fascia, rectus muscle, internal oblique, transverse abdominis, transversalis fascia, and peritoneum. The blood supply of the abdominal wall that is interrupted is the distal aspect of the superior epigastric as well as the inferior epigastric, perforating intercostal arteries, and external oblique perforators. This incision is associated with a slight increase in pain during the post-operative phase due to the severing of the rectus muscle. The incision closure is after the procedure in a layered fashion by suturing and approximating fascial layers.
Para-median Incision
The para-median incision serves to expose lateral viscera. It is made 3cm, on average, lateral to the midline. The skin and subcutaneous tissue must be incised, the anterior rectus sheath and the rectus muscle is deflected laterally if possible to expose the posterior rectus sheath if above the arcuate line. Upon passing the rectus is entry to the peritoneum. Peripheral branches of the inferior epigastric will undergo ligation.
Gridiron Incision (McBurney Incision)
This incision provides good exposure for performing open appendectomies and is made obliquely at the McBurney point, two thirds from the umbilicus to the anterior superior iliac spine. Dissection will have to be made down to the external oblique, internal oblique, transversalis fascia, and the peritoneum. The superficial epigastric, as well as perforating branches of inferior epigastric, may be interrupted during this incision.
Lanz (Rockey-Davis)
Lanz incision is similar to a gridiron incision and is useful for open appendectomies. It is made at the McBurney point with the same anatomical layers as well as the blood supply. However, the Lanz incision is a horizontal incision, while the gridiron incision is on an oblique angle.
Thoracoabdominal (Iver Lewis)
The thoracoabdominal incision is a unique incision that connects the pleural cavity and the peritoneal cavity; it yields great exposure to lateral organs, retroperitoneal space, pleural space, and the distal esophagus. Right-sided incisions may yield proper exposure to the hepatic region as well as the right kidney. A left-sided incision may yield exposure for the stomach as well as the distal esophagus.
When performing this incision, the patient is placed with their abdomen tilted 45 degrees from horizontal, and the thorax twisted into the completely lateral position. This position will expose the abdomen as well as the lateral thoracic region. A vertical incision through the left or right upper quadrant is made to explore the abdominal contents first, and then the incision is extended through the eighth intercostal space from medial to lateral for pleural exposure. The incision will disrupt the rectus abdominis, the oblique muscles, if placed lateral, as well as the transversus abdominis. The thoracic end extends through the intercostals, as well as the latissimus dorsi muscle. Once the thoracic cavity is entered, the lung is deflated. The two incisions should meet at a sharp angle for cleaner closure. Blood supply to the latissimus dorsi is the thoracodorsal artery. This blood supply may be interrupted during the pleural incision laterally. The abdominal incision could lead to disruption in superior epigastric branches.
Chevron
The chevron incision is one that crosses the midline of the abdomen. It is a sub-costal incision that extends from the mid to lateral costal ridge, across the midline to the contralateral side. This approach may provide valuable exposure for hepatic, pancreatic, upper gastrointestinal region, adrenal, or renal surgeries. It provides access to the intra-abdominal cavity as well as the retroperitoneal space. The blood supplies that may be interrupted are the bilateral superior epigastric. The abdominal wall will have collaterals from the perforating branches through the oblique muscles as well as the inferior epigastric meaning there will be no devascularized tissues. However, if there is another surgery after a chevron takes place, and the incision is through the lower abdominal wall, there may be an interruption of the inferior epigastric and middle of the abdominal wall with the least amount of collateral blood supply may ultimately be devascularized.
Pfannenstiel (Kerr/Pubic incision)
The Pfannenstiel is a transverse lower abdominal incision that is made superior to the pubic ridge. Dissection is made through the skin and subcutaneous fat; the anterior rectus sheath is divided transversely. The rectus muscle is open vertically in the midline sparing the muscle fibers from being divided. The peritoneum is then entered through a vertical incision. This approach is most frequently used for urologic, orthopedic, pelvic, and cesarean sections. The major drawback of this incision is its limited exposure beyond the pelvis. Blood supply to keep in mind is the inferior epigastric branches as well as the superficial epigastric.
McEvedy
The McEvedy is a vertical incision from the femoral canal and brought superior to above the inguinal ligament. It opens the femoral space to allow access to the femoral canal as well as the peritoneum. Femoral hernias may be reduced and repaired through this incision. If the peritoneal cavity needs to be accessed, this will provide minimal access, as the incision is not really over the peritoneal space. Due to the location on top of the femoral canal, special care needs to be taken not to injure the femoral vein, artery, or nerve.
Subclavicular Incision (Infraclavicular incision)
Made transversely through the skin and subcutaneous tissues inferior to the clavicle, giving access to the subclavian vessels. However, if access to the distal subclavian artery is needed, then a supraclavicular incision may be utilized.
Supraclavicular Incision
This incision is a transverse incision superior to the clavicle. It may extend along the length of the clavicle to the midline of the sternum and will provide access from another vantage point to the subclavian vessels. The advantage of this incision is that it can meet a sternotomy incision or a cervical incision to provide greater exposure to cervical anatomy or thoracic anatomy. When making this incision, care must be taken medially to avoid the internal and external jugular veins. The platysma will be severed, and the incision provides access to the anterior scalenes as well. This approach is most often utilized in trauma to gain access to the subclavian vessels.
Median Sternotomy
The sternotomy is a vertical incision over the sternum. It is used to access the mediastinum, pleural cavity, the aorta and branches to the head and upper extremities, as well as the epigastric region. It is the most commonly used open heart incision.
Trapdoor Incision
The trapdoor incision is a combination of the collar incision, the sternotomy, as well as a laterally extended incision from the inferior aspect of the sternotomy below the pectoral muscles. This incision is used rarely to control bleeding from penetrating trauma to zone three of the neck, and on occasion is used for aortic arch aneurysms. The trapdoor incision opens a “door” to the pleural space, the mediastinum, the cervical vasculature, and the heart. The three incisions that are used still need to be conducted carefully due to the vascular supply as well as the nerves running along the anterior chest wall. The blade used needs to be handled with care because if it is too deep then the lung, aorta, or other major vascular structures may be injured, leading to hemorrhage.
Clamshell
Clamshell incision is a large transverse incision that spans across the entire chest wall. It is also known as a bilateral thoracotomy and is used during massive chest trauma, lung transplant, or resection of tumors in the chest. The incision extends through the sternum, between the fourth and fifth ribs bilaterally, and extends to the mid-axillary line. Mammary vessels will be interrupted as well as intercostal muscles with associated intercostal nerves and vessels.
Mercedes-Benz
This incision is a modification on the chevron incision. It is the classic chevron with a vertical incision that extends through the xiphoid and the sternum. This modification is used in liver transplants or any epigastric pathology that needs adequate exposure for debulking or total removal.
Supra-umbilical/Infra-umbilical
Supra and infra-umbilical incisions are used for access into the peritoneum through the tissues surrounding the umbilicus. Due to the umbilical stalk, it is unwise to incise directly through the umbilicus so the incision must route around it. Infra-umbilical incisions may be vertical (such as when gaining access for a Hasson port) along the linea alba, which is avascular. The incision may be transverse if the surgeon is performing an open umbilical hernia repair. Supra-umbilical incisions may be used to gain access into the peritoneum or for open umbilical hernia repairs when there have been previous incisions in the infra-umbilical region. If the transverse incision is made, then it may be used in a tight “U,” or inverted “OMEGA” shape around the umbilicus to keep the future scar hidden, or it can be curvilinear to match the natural curve of the umbilical ridge. However, one must make sure not to de-vascularize the umbilical stalk or the thin umbilical skin. If an incision is made along the umbilical ridge, then there must be enough untouched skin on the opposing side of the incision to provide sufficient blood supply.
Pararectus
A para-rectus is an incision that is made through the semilunar line laterally to the rectus abdominis muscle. This incision may be used for a Spigelian hernia, or if modified, can be used for an ostomy. If the incision is made circularly and the rectus abdominis is not incised but retracted, then the incision can be carried through to the peritoneum to retrieve the intestine for ostomy formation. How inferior or superior the incision is located will affect blood supply either from the inferior epigastric, the superior epigastric or in the watershed zone between the two main arteries.
Maylard Incision (Mackenrodt)
A transverse incision 6cm above the pubic tubercle that is made through the rectus abdominis to gain access to pelvic structures. The incision is made through the rectus abdominis on both sides, through the linea alba, and the medial aspects of the obliques. The portions of inferior epigastric, as well as the superficial epigastric, will be damaged.
Gibson (either side but conventionally left)
Three centimeters above and parallel to the inguinal ligament is the Gibson incision. It is used in gynecological procedures as well as urological procedures.
Inguinal incision (Groin)
The inguinal incision is a transverse or oblique incision over the inguinal canal. This incision is used for open inguinal hernia repairs. The incision is made through the skin to the subcutaneous fat, through Camper and Scarpa fascia. The superficial epigastric veins are commonly encountered and ligated. This incision reaches the external oblique aponeurosis and provides access to the inguinal canal.
Neck Incisions
Carotid/thyroidectomy/tracheostomy
A carotid incision is used to access the carotid sheath for carotid endarterectomy. It is made along the anterior aspect of the sternocleidomastoid muscle in a vertical direction. There needs to be are to avoid hitting the external jugular vein or the internal jugular vein. The incision will need to go through the platysma.
Thyroidectomies are performed through a transverse incision superior to the sternal notch, and it travels parallel to the clavicles, preferably in the neck crease. Care needs to be taken to not to cut the anterior veins by cutting too deep too quickly, or this will result in heavy bleeding.
Tracheostomies are performed through a vertical or horizontal incision that overlays the trachea, superior to the thyroid over the second or third tracheal rings.
Laparoscopic Incisions
Initial access is usually best achieved at the umbilicus either by using a Veress needle or the cut-down method using a Hassan trochar. A Visi port is a special port that allows for laparoscope placement in the trochar itself, then after an incision is made, direct visualization with twisting of the port and steady downward pressure is applied to gain access to the intraperitoneal space. When additional trochars are placed, it is wise to avoid any vessels that are traveling through the abdominal wall that may be illuminated by the laparoscope inserted through the previously inserted larger port. If access at the umbilical site is not advisable due to multiple surgeries, the presence of scar tissue, or large wall deformities, then the next best initial access site is the left upper abdomen. Decompression of both the stomach and bladder is recommended before any initial trochar insertion.
Clinical Significance
In order to access different organs in the body, surgeons need to know where to make the incisions and the length. An improper incision not only makes the surgery difficult but may also lead to injury of other structures. In general, for abdominal surgery, the midline incision is versatile and allows access to most organs. However, it can lead to a huge cosmetic defect. For the chest, both the thoracotomy and median sternotomy allow exposure to many thoracic structures. The key is for surgeons to be familiar with nearby structures and avoid injury. All incisions have the potential for keloids and hernia formation; which patients should be told about prior to surgery.
