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*ePTFE, expanded PolyTetraFluoroEthylene.

Absorbable suture materials degrade completely, last a variable time, and leave no permanent foreign body.

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Absorbable sutures are made of collagen or synthetic polymers and degrade by enzymatic digestion or hydrolysis. These sutures cause more tissue reaction than nonabsorbables, especially if enzymatically degraded (collagen).

Absorbable sutures are ideal for the biliary and urinary tracts, where a permanent suture can serve as a nidus for stone formation.

There may be a decreased infection risk without the permanent foreign body to harbor bacteria.

There are no permanent knots to bother patients.

If the suture loses strength before wound healing is adequate, the risk of wound disruption or incisional hernia increases.

Braided, multistrand sutures tend to be stronger, size for size, than monofilaments.

This is especially true for shear strength (as opposed to tensile strength), which is most important at the knot.

Braided sutures are softer, more flexible, and more pliant and hence are easier to handle, easier to tie, and require fewer throws to form a secure knot.

Because braided sutures have interstices in which bacteria can hide, the risk of infection may be increased.

Braided sutures are coarser, have increased drag on tissue, and can tear fragile tissue.

Monofilament sutures have much less drag when pulled through tissue, cause less tissue reaction, and have much less risk of harboring infection.

Because monofilament sutures are stiffer, they require more throws to form a secure knot. The knots can be large and bothersome to the patient.

Monofilament sutures must be handled with greater care; crushing, crimping, twisting, or kinking weakens the strand, which can lead to suture breakage.

Sutures can also be classified as natural materials or synthetic. Both require extensive processing.

Suture size uses a scale with “0” in the middle.

Smaller sizes. As the number of 0's rises, the sutures get finer, e.g., 4-0 (0000) is smaller than 3-0 (000). The smallest standard manufactured suture size is 10 -0 (pronounced ten-oh ).

Larger sizes. The sizes increase with each integer: no. 1 and no. 2. No. 2 is the largest standard manufactured suture size.

Usage of types of sutures

Braided permanent sutures are the easiest to handle but are known for their increased risk of harboring infection, and so they have fallen out of common use for fascial closures. Examples include silk, polyester, and cotton.

Braided absorbable sutures are the most used suture material. They can be used for gastrointestinal (GI) and other visceral surgery and for general closures. Examples include polyglactin-910 and polyglycolic acid.

Monofilament permanent sutures are stiff and harder to work with but are best for cardiovascular surgery (in small sizes) and fascial closures and hernias (in larger sizes). Examples include nylon, polypropylene, and stainless steel.

Monofilament absorbable synthetic sutures are the latest suture type to be developed. As both gut and chromic gut degrade quickly, the synthetic sutures have almost replaced the gut materials. They are better than braided absorbables for fascia because they last longer. They are also widely used for biliary and urinary tract surgery. Examples include polydioxanone and polyglyconate.

ePTFE sutures are a permanent porous monofilament with properties of both braided (interstices that can harbor bacteria, easy to handle, soft inconspicuous knots) and monofilament (slippery, requires six to eight throws to secure a knot) sutures.

Stapling devices fire multiple rows of small titanium staples for GI, vascular, and pulmonary applications. The staples act similarly to permanent monofilament sutures in that they are nonreactive, do not harbor

bacteria, and are permanent. Titanium has replaced steel for permanent implantables because of its compatibility with magnetic resonance imaging (MRI).

II Surgical Tubes

A Drainage tubes

Various types of tubes are used to drain either normal body fluid that cannot be handled by the body or abnormal material, such as pus. A tube can be mandatory, such as a chest tube for a hemothorax, or optional.

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Types of drains

Closed drains are tubes connecting a body cavity to a sealed reservoir.

Gravity drainage allows fluid to drain through the tube into a reservoir at a lower level (e.g., Foley bladder catheter).

Underwater -seal drainage systems prevent air and fluid from re-entering the body. The end of the drainage tube is under water in a sealed drainage bottle at floor level. The water prevents air from reentering the tube and prevents fluid from siphoning back (e.g., chest tube).

Suction drainage applies suction to a drainage tube and can drain large volumes of fluid, such as fluids that can collect in the GI tract. It also promotes closure of “dead space,” allowing a better approximation of tissue surfaces (e.g., Jackson -Pratt drain).

Sump drains are double -lumen catheters that allow air or irrigation fluid to enter through one lumen while suction is applied to the other lumen. Sump drains are used to evacuate particulate matter, such as debris from an abscess, or as continuous irrigation catheters (e.g., nasogastric [NG] tube).

Open drains are not sealed at either end. They allow bacteria and other materials access to the drained area. Open drains are still used for some contaminated cases (e.g., Penrose drain).

Examples of situations requiring drainage

Chest tube drainage of the pleural space is usually indicated to evacuate air, i.e., pneumothorax (simple, tension), and blood, i.e., hemothorax.

A GI tract that is nonfunctional for a prolonged period (more than 1 or 2 days) or obstructed requires NG drainage, usually with a sump tube.

The decompression lessens abdominal distention, intestinal dilatation, nausea, and vomiting.

Drainage also allows one to determine the amount and type of luminal fluid loss so that appropriate replacement can be made.

Areas where bodily fluids (e.g., bile, urine, pancreatic fluid) can collect internally require drainage.

Procedures such as mastectomies or skin flaps (see Chapter 1, V D 5) where large raw surfaces are to be kept opposed require suction drainage.

Deep abscesses not amenable to simple incision require drainage (e.g., deep cavities such as subphrenic or periappendiceal abscesses). Drains cannot be used to control a generalized infection, such as cellulitis or peritonitis (see VI B 2).

Caveats and complications

The presence of a drain is no guarantee that a fluid collection will not form. The foreign body reaction can isolate a drain from adjacent tissues, preventing fluid from accessing the drain's lumen.

A drain is not a substitute for hemostasis. If hemostasis is not adequate, a hematoma will likely develop despite drainage.

Drains can become colonized by microorganisms from exogenous sources. Drains, particularly open drains, increase the risk of infection.

Rigid drains may erode through the wall of a blood vessel or a hollow intestinal structure. This complication can be minimized by using soft drains and removing drains early.

Excessive suction on a tube can cause necrosis of nearby structures. Intermittent or low -level suction or use of a sump tube is safer.

A drain in direct contact with a fistula may perpetuate the fistula and delay its healing. The drain must then be withdrawn from the fistula if healing is to occur (see VII E 2).

Drains can retract into the body. They must always be firmly attached to the skin and should be marked with a radiopaque marker. A safety pin can be used to keep small drains outside the body.

The free peritoneal space cannot be drained because tubes are quickly “walled off.” Therefore, diffuse peritonitis cannot be drained. Localized collections can be drained.

Removal. Drains should be removed when they have fulfilled their purpose.

When the main risk of leakage has passed , the drain is removed.

After a liver resection, if a leak from a bile duct is present, it should be evident in 1 or 2 days. Therefore, drains are normally removed by the third day.

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After urinary bladder procedures, a urine leak would not be noticeable until the bladder catheter is removed. Therefore, drains are removed a day after the catheter is removed.

When a drain is used for postoperative fluid collections (i.e., blood or lymph), it is removed when no substantial drainage occurs.

When the drain is used in a reconstructive procedure, it is removed once the repair is safe.

After common duct exploration, a T tube is used to drain the bile duct until spasm of the sphincter of Oddi has resolved. The T tube is removed after a cholangiogram documents free flow of bile into the duodenum.

After gastrectomy and Billroth II reconstruction, a potential complication is disruption of the duodenal stump.

A tube may be placed within the duodenal lumen (tube duodenostomy) to prevent overdistention of the proximally closed duodenum and prevent disruption.

Once the patient has recovered from the surgical procedure and if no signs of duodenal leakage

have developed, the tube can be removed 2–4 weeks after surgery.

B Gastrointestinal tubes

Gastrostomy tubes are tubes inserted between the stomach and the skin and are used for feeding purposes or for prolonged gastric decompression.

Once the tube is no longer needed, it is removed. The tract formed between the skin and stomach will close in

A port is equivalent to a central venous catheter or PICC, except there is no external extension, and a port is intended for longer -term use. The catheter is attached to a device with a septum (the port) through which to access the lumen. The port is buried subcutaneously. A port is usually used less often than daily, e.g., for periodic chemotherapy.

A cuffed central venous catheter (Hickman -type catheter) maintains access to the veins for prolonged time periods.

The catheter has a Dacron felt cuff glued to the catheter. The cuff provokes ingrowth of granulation tissue, which functions to secure the catheter's position and as a mechanical barrier to organisms entering via the skin exit site.

They can function for years. Both single - and double -lumen styles are available; they are inserted percutaneously.

Typical uses include:

Chemotherapy and phlebotomy in patients with malignant diseases.

Hemodialysis in patients with problems with standard hemoaccess.

Long-term hyperalimentation in patients with nutritional problems.

Tenckhoff peritoneal dialysis catheters are inserted into the peritoneal cavity either for long-term dialysis therapy or for management of ascites in patients with malignant disease.

They may be inserted either percutaneously or surgically and can function for years if properly maintained with sterile technique.

Two Dacron cuffs are glued to the catheter: one adjacent to the peritoneum and one adjacent to the skin exit site. The cuffs function as barriers against infection (from the skin side) and leakage (from the peritoneal side).

III Hernias

Hernias are the abnormal protrusion of intra -abdominal contents through a defect in the abdominal wall.

A Overview

Frequency of occurrence. In both men and women, hernias occur most commonly in the inguinal region (75%–80% of all hernias). Incisional (ventral) hernias occur next in frequency (8%–10%), followed by umbilical hernias (3%– 8%).

Etiology. Hernias occur as a result of various factors.

Congenital defects include indirect inguinal hernia.

Loss of tissue strength and elasticity from aging or repetitive stress may result in herniation, as in hiatal hernia.

Trauma , especially operative trauma in which normal tissue strength is altered surgically, can lead to the development of hernia. A wound infection greatly increases the risk of late incisional hernia.

Increased intra -abdominal pressure as a result of

Heavy lifting

Coughing, asthma, and chronic obstructive pulmonary disease (COPD)

Bladder outlet obstruction (e.g., benign prostatic hypertrophy)

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Prior pregnancy

Ascites and abdominal distention

Obesity

Descriptive terms. Hernias may be described according to physical or operative findings.

Reducible. The hernia contents can be pushed back into the abdomen.

Incarcerated. The hernia contents cannot be pushed back.

Obstructing. The hernia contains a loop of bowel that is kinked and obstructs the GI tract.

Strangulated. The tissue contained in the hernia is ischemic and will necrose due to compromise of its blood supply.

Sliding. The wall of the hernia sac, rather than being formed completely by peritoneum, is in part formed by a retroperitoneal structure, such as the colon or the bladder.

Richter's hernia. Only one side of the bowel wall is trapped in the hernia (typically, the antimesenteric side) rather than the entire loop of bowel. This is especially dangerous because the incarcerated portion of bowel can necrose and perforate in the absence of obstructive symptoms.

Complications. Hernias should be repaired electively to prevent the development of major complications.

Intestinal obstruction.

Intestinal strangulation with bowel perforation.

B Inguinal hernias

Anatomy of the inguinal region (Figs. 2-2 and 2-3)

The internal inguinal ring is an opening in the transversalis fascia lateral to the inferior epigastric vessels.

The external inguinal ring is an opening in the external oblique aponeurosis.

The inguinal canal is the communication between the internal and external rings.

The anterior wall of the canal is formed by the external oblique aponeurosis.

The inferior wall of the canal is formed by the inguinal ligament (Poupart's ligament ) and its reflection.

The roof of the inguinal canal (superior ) is made up of fibers of the internal oblique and transversus abdominis muscles, forming a structure termed the conjoint tendon.

FIGURE 2-2 Anatomy of the inguinal region.

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FIGURE 2-3 Sites of direct, indirect, and femoral hernias and their relationship to anatomic structures.

The posterior wall or floor is formed by the transversalis fascia.

Within the posterior wall of the inguinal canal is Hesselbach's triangle.

The triangle is formed laterally by the inferior epigastric artery, inferiorly by the inguinal ligament, and superomedially by the lateral border of the rectus sheath.

In women , the round ligament traverses the inguinal canal.

In men, the spermatic cord structures pass into the internal ring, traverse the inguinal canal, and pass through the external ring into the scrotum. Structures within the spermatic cord include:

Arteries: testicular and cremasteric

Veins: pampiniform plexus

Vas deferens

Processus vaginalis: an evagination of peritoneum that accompanies the descent of the testicle and gubernaculum through the abdominal wall. Normally obliterated, it remains patent in an indirect hernia and forms the hernia sac.

Nerves: the ilioinguinal and genital branch of the genitofemoral nerves are within the inguinal canal but are external to the cremasteric fascia, which invests the spermatic cord.

Types of hernias

Indirect inguinal hernias

An indirect inguinal hernia passes from the peritoneal cavity through the internal inguinal ring (i.e., lateral to the epigastric vessels) and down the inguinal canal (Fig. 2-3). It may, on occasion, extend into the scrotum.

When the processus vaginalis is incompletely obliterated, a spermatic cord hydrocele may result, with or without an indirect inguinal hernia.

Incidence

Indirect inguinal hernias are the most common type of hernia in both men and women. They are 5 to 10 times more common in men than in women. Approximately 5% of men develop an inguinal hernia during their lifetime and require an operation.

Indirect inguinal hernias are five times more common than direct hernias.

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Indirect hernias may occur from infancy to old age but generally occur by the fifth decade of life.

A pediatric inguinal hernia (see Chapter 29, II) is almost always indirect and has a high risk of incarceration. It is more common on the right (75%) and is often bilateral.

Potential indirect hernias are associated with an undescended testis, a testis in the inguinal canal, and a hydrocele.

Bilateral patent processus vaginalis occurs in up to 10% of patients with an indirect inguinal hernia.

Direct inguinal hernias. The inferior epigastric vessels are the anatomic landmarks that distinguish indirect from direct inguinal hernias, which occur medial to the epigastric vessels.

A direct inguinal hernia occurs through the floor of the inguinal canal, i.e., through Hesselbach's

triangle (Fig. 2-2), because of an acquired weakness in the tissue.

The hernia is a direct protrusion of abdominal structures into the floor of the canal posterior to the spermatic cord. It is not contained in the cord as is an indirect hernia, and it does not pass into the scrotum. The sac is a broadly based defect. It is much less often associated with strangulation than an indirect inguinal hernia.

Direct inguinal hernia increases in occurrence with age and is related to physical activity.

A recurrent inguinal hernia usually recurs as a direct hernia. Most commonly, the defect occurs in the most medial aspect of the repair of the floor of the inguinal canal.

Pantaloon hernias are combinations of direct and indirect hernias in which the hernia sac passes both medially and laterally to the epigastric vessels.

Femoral hernias

A femoral hernia occurs along the femoral sheath in the femoral canal (Fig. 2-3).

The hernia contents protrude posterior to the inguinal ligament, anterior to the pubic ramus periosteum (i.e., Cooper's ligament ), and medial to the femoral vein.

The hernia traverses the femoral canal and can present as a mass at the level of the foramen ovale. It may also turn cephalad once it has exited the foramen ovale and can cross anteriorly to the inguinal ligament.

The sac has a narrow neck, and 30%–40% of femoral hernias become incarcerated or strangulated.

Femoral hernias are more common in women than in men.

Femoral hernias are associated with being female, prior pregnancy, and prior inguinal hernia repair.

Diagnosis of an inguinal hernia is based on history and physical examination.

The history may include the appearance of a lump in the groin. The mass may be intermittently present and may be painful. Its appearance is often associated with activity.

Physical examination should be performed with the patient in both the supine and standing positions.

A mass may be visible, and its size and visibility may depend on the patient's position.

The mass may be tender or may be reducible with gentle pressure.

The examining finger should be placed along the spermatic cord at the scrotum and passed into the external ring along the canal.

The mass may become palpable as an impulse felt by the examining finger upon a sudden increase in intra -abdominal pressure, as occurs with a cough.

A direct hernia causes a forward bulge low in the canal.

An indirect hernia touches the tip of the examining finger.

The differential diagnosis of an inguinal mass includes a hydrocele, a varix (especially if thrombosed), an inflamed or enlarged lymph node, a lipoma of the spermatic cord, an undescended testicle, or an abscess or tumor.