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Umbilical Herniorrhaphy
CHAPTER 45 Umbilical Herniorrhaphy David A. Wilson
with a peritoneal lining (hernial sac). The hernial sac generally contains small intestine.
INDICATIONS Uncomplicated congenital umbilical hernias that have persisted until 5 to 6 months of age, gradually enlarged over time, or failed to respond to conservative therapy.1 Complications may develop in congenital umbilical hernias, which can significantly increase the complexity and expense of repair. One report has shown a complication rate of 8.8%.2 Hernia repair before these complications develop is desirable.
PROCEDURE Closed Herniorrhaphy An approximately 10-cm fusiform incision is centered over the umbilicus. Generally, intestine will be palpable within the hernial sac and the hernia can be readily reduced. The incision is continued through the subcutaneous tissue with care taken to not penetrate the hernial sac. The skin and subcutaneous tissues are dissected from the hernial sac (Figure 45-1). At the attachment of the umbilicus, the hernial sac can be very thin and is easily penetrated. If the sac is penetrated, the defect in the sac is closed with No. 2-0 absorbable suture material. The hernial sac is then inverted into the abdomen (Figure 45-2). Absorbable sutures (No. 1 or No. 2 depending on the size of the foal) are placed in the fibrous hernial ring, with care taken to not incorporate intestine into the suture line (Figures 45-3 and 45-4). The specific suture pattern for closure of the hernial ring is left to the discretion of the surgeon. Simple interrupted, cruciate, and far-near-near-far patterns are commonly used. The advantages of the closed method of repair are the relative ease of the procedure and the reduced risk of postoperative peritonitis or evisceration. Disadvantages include not being able to thoroughly assess the contents of the hernial sac,
EQUIPMENT No special equipment is required for surgical repair of umbilical hernias.
PREPARATION AND POSITIONING The surgery is performed with the horse under general anesthesia in dorsal recumbency. The ventral abdomen is clipped, prepared, and draped for aseptic surgery. In males, the bladder may be catheterized in males and the prepuce closed with towel clamps or suture to minimize urine contamination of the surgery site.
ANATOMY An umbilical hernia consists of a midline defect in the body wall and an outpouching of the skin
250
Umbilical Herniorrhaphy
251
A B Figure 45-1 A, Sharp dissection of skin from hernial sac. B, The hernial sac and overlying skin are held before removal of skin from sac.
Figure 45-2 After removal of skin from the hernial sac and before closure, the sac is inverted into the abdomen.
Figure 45-4 The hernial sac is inverted into the abdomen and the thickened fibrous ring (arrow) is closed.
the potential for incorporation of intestine in the suture line, and, in large hernial sacs (larger than a tennis ball), the potential for ischemic necrosis of the hernial sac and subsequent aseptic peritonitis. The closed technique is indicated for repair of most uncomplicated hernias.
Figure 45-3 The first bite of closure inserts the needle into the edge of the fibrous hernial ring and inverted hernial sac.
Open Herniorrhaphy The approach for the open technique is similar to the closed technique until the hernial sac is
252
Limited Abdominal Surgeries
exposed. At this point, the hernial sac is resected to the level of the fibrous ring of the hernia. Careful palpation of the hernial ring will identify a thinned triangular area on the cranial and caudal borders of the ring with the fibrous portions of the linea alba in a fusiform shape (Figure 45-5). The tissue within this triangular area may be removed. Closure of the abdominal wall consists of appositional absorbable sutures (No. 1 or No. 2 depending on the size of the foal). The suture patterns are similar to those recommended for the closed technique. The vest-over-pants or Mayo mattress suture pattern is not recommended because the pattern tends to excessively focus or increase the tension of the suture line rather than simply closing the space between the fibrous portions of the hernial ring.3 The only significant advantage of the open technique is the ability to assess the contents of the hernial sac. The disadvantages of the open technique are the slightly increased risk of postoperative evisceration, abdominal adhesions, and
peritonitis. The open technique is indicated for repair of large hernias, irreducible hernias, or hernias complicated by enterocutaneous fistula. The subcutaneous tissue and skin are closed similarly for both open and closed techniques. The suture material and patterns are left to the surgeon’s preference. We use No. 2-0 polydioxanone, polyglactin 910, or poliglecaprone. A subcuticular layer in the skin rather than traditional skin closure or the use of absorbable sutures in the skin eliminates the need for suture removal.
POSTOPERATIVE CARE Postoperative Care Exercise Restrictions: The foal should be rested in a stall or small paddock for at least 4 weeks prior to returning to unrestricted pasture turnout or turnout with other foals. The incision line should be palpated and examined for adequate healing before unrestricted exercise is allowed. Medications: If the procedure is uncomplicated, only preoperative antibiotics and anti-inflammatory agents are indicated. Tetanus prophylaxis should be current. Suture Removal: Nonabsorbable sutures should be removed in 10 to 14 days.
Palpable border of defect in linea alba
EXPECTED OUTCOME If the margins of the body wall defect are carefully identified during surgery and adequate tissue bites are obtained using strong nonreactive suture material, closed and open hernia repairs have a high success rate. Mild periincisional edema is common during the first postoperative week.
Hernial sac
COMPLICATIONS
A
B
Figure 45-5 A, Careful palpation of the hernial ring will identify a thinned triangular area on the cranial and caudal borders of the ring with the fibrous portions of the linea alba in a fusiform shape. B, The tissue within this triangular area (black arrow) may be removed along with the fibrous tissue forming the base of the triangle (white arrow), in an open herniorrhaphy. Dotted line indicates the line of incision.
Reported complication rates for either surgical hernia repair or the clamp technique have been reported to be between 7% and 19%.4,5 Seroma formation is probably the most common complication associated with both surgical techniques and generally occurs as a result of inadequate closure of subcutaneous dead space. Hematomas may also occur if inadequate hemostasis occurred during surgery. Generally, hematomas and seromas regress on their own and require no
Umbilical Herniorrhaphy
specific therapy. However, seroma and hematoma formation may progress to subcutaneous infection, which can be determined by the presence of focal tenderness, persistent inflammation, and moisture or discharge at the suture sites. Subcutaneous infections are treated with warm compresses and systemic antibiotic therapy. If not resolved by 10 to 14 days postsurgery, ultrasonography may be used to identify subcutaneous abscesses and needle aspiration or lancing of the abscesses considered. Uncommon complications associated with the open technique include evisceration, abdominal adhesions, and peritonitis.
ALTERNATIVE PROCEDURES The advantages of hernial clamping or the application of elastrator rings have been reported to be ease of application and cost.1,5,6 The primary disadvantage of hernial clamping is the risk of incorporating gut into the clamp and inadequate fibrosis of the abdominal wall defect. The procedure should be done under general anesthesia with the foal in dorsal recumbency. Clamping is recommended only for hernias that are uncomplicated, easily reducible, and less than 8 cm in length. Additionally, the hernial sac should be easily palpable to ensure there are no contents within the sac when applying the clamp. Some surgeons believe that clamping is easier in females than in males as the prepuce can get in the way in males. In males, the smallest possible clamp should be selected and carefully padded to prevent injury to the foal’s sheath.5
COMMENTS Umbilical hernias are a common congenital defect in young horses. Females are twice as likely as males to have the defect.7 Many hernias are small and will resolve with time or with more conservative measures such as manual daily reduction, the application of a truss, or umbilical clamps.1 Umbilical hernias generally require surgery if they persist until 5 to 6 months of age, if they gradually enlarge over time, or if they fail to respond to conservative therapy. Most hernias are uncomplicated and reducible. Some (8% to 10%) sustain complications that are life threatening and
253
mandate emergency surgery.2,8,9 Hernias that suddenly increase in size, become edematous or painful, or are associated with depression or colic warrant urgent clinical evaluation and exploratory surgery. Hernias that exhibit these signs are not amenable to field surgery, and the horse should be referred to an appropriate surgical facility. Careful evaluation of the umbilical masses by palpation and ultrasonography will help to differentiate complicated umbilical hernias from the uncomplicated, reducible hernias. The goals of surgical repair of an umbilical hernia are obliteration of the hernial sac and repair of the defect in the abdominal wall. Alternatives to surgical repair of hernias include the application of hernial clamps or elastrator rings and the injection of irritating substances around the base of the hernial sac. These alternatives are usually successful in obliterating the hernial sac but do not directly repair the defect in the abdominal wall.
REFERENCES 1. Adams SB, Fessler JF: Umbilical herniorrhaphy. In Adams SB, Fessler JF, editors: Atlas of equine surgery, Philadelphia, 2000, WB Saunders. 2. Freeman DE, Orsini JA, Harrison IW, et al: Complications of umbilical hernias in horses: 13 cases (1972-1986), J Am Vet Med Assoc 192:804, 1988. 3. Orsini JA: Management of umbilical hernias in the horse: treatment options and potential complications, Equine Vet Educ 9:7, 1997. 4. Wilson DA, Baker GJ, Boero MJ: Complications of celiotomy incisions in horses, Vet Surg 24:506, 1995. 5. Riley CB, Cruz AM, Bailey JV, et al: Comparison of herniorrhaphy versus clamping of umbilical hernias in horses: a retrospective study of 93 cases (19821994), Can Vet J 37:295, 1996. 6. Greenwood RES, Dugdale DJ: Treatment of umbilical hernias in foals with elastrator rings, Equine Vet Educ 5:113, 1993. 7. Freeman DE, Spencer PA: Evaluation of age, breed, and gender as risk factors for umbilical hernia in horses of a hospital population, Am J Vet Res 52:637, 1991. 8. Steckel RR, Nugent MA: Parietal hernia in a horse, J Am Vet Med Assoc 182:818, 1983. 9. Markel MD, Pascoe JR, Sams AE: Strangulated umbilical hernias in horses: 13 cases (1974-1985), J Am Vet Med Assoc 190:692, 1987.
with a peritoneal lining (hernial sac). The hernial sac generally contains small intestine.
INDICATIONS Uncomplicated congenital umbilical hernias that have persisted until 5 to 6 months of age, gradually enlarged over time, or failed to respond to conservative therapy.1 Complications may develop in congenital umbilical hernias, which can significantly increase the complexity and expense of repair. One report has shown a complication rate of 8.8%.2 Hernia repair before these complications develop is desirable.
PROCEDURE Closed Herniorrhaphy An approximately 10-cm fusiform incision is centered over the umbilicus. Generally, intestine will be palpable within the hernial sac and the hernia can be readily reduced. The incision is continued through the subcutaneous tissue with care taken to not penetrate the hernial sac. The skin and subcutaneous tissues are dissected from the hernial sac (Figure 45-1). At the attachment of the umbilicus, the hernial sac can be very thin and is easily penetrated. If the sac is penetrated, the defect in the sac is closed with No. 2-0 absorbable suture material. The hernial sac is then inverted into the abdomen (Figure 45-2). Absorbable sutures (No. 1 or No. 2 depending on the size of the foal) are placed in the fibrous hernial ring, with care taken to not incorporate intestine into the suture line (Figures 45-3 and 45-4). The specific suture pattern for closure of the hernial ring is left to the discretion of the surgeon. Simple interrupted, cruciate, and far-near-near-far patterns are commonly used. The advantages of the closed method of repair are the relative ease of the procedure and the reduced risk of postoperative peritonitis or evisceration. Disadvantages include not being able to thoroughly assess the contents of the hernial sac,
EQUIPMENT No special equipment is required for surgical repair of umbilical hernias.
PREPARATION AND POSITIONING The surgery is performed with the horse under general anesthesia in dorsal recumbency. The ventral abdomen is clipped, prepared, and draped for aseptic surgery. In males, the bladder may be catheterized in males and the prepuce closed with towel clamps or suture to minimize urine contamination of the surgery site.
ANATOMY An umbilical hernia consists of a midline defect in the body wall and an outpouching of the skin
250
Umbilical Herniorrhaphy
251
A B Figure 45-1 A, Sharp dissection of skin from hernial sac. B, The hernial sac and overlying skin are held before removal of skin from sac.
Figure 45-2 After removal of skin from the hernial sac and before closure, the sac is inverted into the abdomen.
Figure 45-4 The hernial sac is inverted into the abdomen and the thickened fibrous ring (arrow) is closed.
the potential for incorporation of intestine in the suture line, and, in large hernial sacs (larger than a tennis ball), the potential for ischemic necrosis of the hernial sac and subsequent aseptic peritonitis. The closed technique is indicated for repair of most uncomplicated hernias.
Figure 45-3 The first bite of closure inserts the needle into the edge of the fibrous hernial ring and inverted hernial sac.
Open Herniorrhaphy The approach for the open technique is similar to the closed technique until the hernial sac is
252
Limited Abdominal Surgeries
exposed. At this point, the hernial sac is resected to the level of the fibrous ring of the hernia. Careful palpation of the hernial ring will identify a thinned triangular area on the cranial and caudal borders of the ring with the fibrous portions of the linea alba in a fusiform shape (Figure 45-5). The tissue within this triangular area may be removed. Closure of the abdominal wall consists of appositional absorbable sutures (No. 1 or No. 2 depending on the size of the foal). The suture patterns are similar to those recommended for the closed technique. The vest-over-pants or Mayo mattress suture pattern is not recommended because the pattern tends to excessively focus or increase the tension of the suture line rather than simply closing the space between the fibrous portions of the hernial ring.3 The only significant advantage of the open technique is the ability to assess the contents of the hernial sac. The disadvantages of the open technique are the slightly increased risk of postoperative evisceration, abdominal adhesions, and
peritonitis. The open technique is indicated for repair of large hernias, irreducible hernias, or hernias complicated by enterocutaneous fistula. The subcutaneous tissue and skin are closed similarly for both open and closed techniques. The suture material and patterns are left to the surgeon’s preference. We use No. 2-0 polydioxanone, polyglactin 910, or poliglecaprone. A subcuticular layer in the skin rather than traditional skin closure or the use of absorbable sutures in the skin eliminates the need for suture removal.
POSTOPERATIVE CARE Postoperative Care Exercise Restrictions: The foal should be rested in a stall or small paddock for at least 4 weeks prior to returning to unrestricted pasture turnout or turnout with other foals. The incision line should be palpated and examined for adequate healing before unrestricted exercise is allowed. Medications: If the procedure is uncomplicated, only preoperative antibiotics and anti-inflammatory agents are indicated. Tetanus prophylaxis should be current. Suture Removal: Nonabsorbable sutures should be removed in 10 to 14 days.
Palpable border of defect in linea alba
EXPECTED OUTCOME If the margins of the body wall defect are carefully identified during surgery and adequate tissue bites are obtained using strong nonreactive suture material, closed and open hernia repairs have a high success rate. Mild periincisional edema is common during the first postoperative week.
Hernial sac
COMPLICATIONS
A
B
Figure 45-5 A, Careful palpation of the hernial ring will identify a thinned triangular area on the cranial and caudal borders of the ring with the fibrous portions of the linea alba in a fusiform shape. B, The tissue within this triangular area (black arrow) may be removed along with the fibrous tissue forming the base of the triangle (white arrow), in an open herniorrhaphy. Dotted line indicates the line of incision.
Reported complication rates for either surgical hernia repair or the clamp technique have been reported to be between 7% and 19%.4,5 Seroma formation is probably the most common complication associated with both surgical techniques and generally occurs as a result of inadequate closure of subcutaneous dead space. Hematomas may also occur if inadequate hemostasis occurred during surgery. Generally, hematomas and seromas regress on their own and require no
Umbilical Herniorrhaphy
specific therapy. However, seroma and hematoma formation may progress to subcutaneous infection, which can be determined by the presence of focal tenderness, persistent inflammation, and moisture or discharge at the suture sites. Subcutaneous infections are treated with warm compresses and systemic antibiotic therapy. If not resolved by 10 to 14 days postsurgery, ultrasonography may be used to identify subcutaneous abscesses and needle aspiration or lancing of the abscesses considered. Uncommon complications associated with the open technique include evisceration, abdominal adhesions, and peritonitis.
ALTERNATIVE PROCEDURES The advantages of hernial clamping or the application of elastrator rings have been reported to be ease of application and cost.1,5,6 The primary disadvantage of hernial clamping is the risk of incorporating gut into the clamp and inadequate fibrosis of the abdominal wall defect. The procedure should be done under general anesthesia with the foal in dorsal recumbency. Clamping is recommended only for hernias that are uncomplicated, easily reducible, and less than 8 cm in length. Additionally, the hernial sac should be easily palpable to ensure there are no contents within the sac when applying the clamp. Some surgeons believe that clamping is easier in females than in males as the prepuce can get in the way in males. In males, the smallest possible clamp should be selected and carefully padded to prevent injury to the foal’s sheath.5
COMMENTS Umbilical hernias are a common congenital defect in young horses. Females are twice as likely as males to have the defect.7 Many hernias are small and will resolve with time or with more conservative measures such as manual daily reduction, the application of a truss, or umbilical clamps.1 Umbilical hernias generally require surgery if they persist until 5 to 6 months of age, if they gradually enlarge over time, or if they fail to respond to conservative therapy. Most hernias are uncomplicated and reducible. Some (8% to 10%) sustain complications that are life threatening and
253
mandate emergency surgery.2,8,9 Hernias that suddenly increase in size, become edematous or painful, or are associated with depression or colic warrant urgent clinical evaluation and exploratory surgery. Hernias that exhibit these signs are not amenable to field surgery, and the horse should be referred to an appropriate surgical facility. Careful evaluation of the umbilical masses by palpation and ultrasonography will help to differentiate complicated umbilical hernias from the uncomplicated, reducible hernias. The goals of surgical repair of an umbilical hernia are obliteration of the hernial sac and repair of the defect in the abdominal wall. Alternatives to surgical repair of hernias include the application of hernial clamps or elastrator rings and the injection of irritating substances around the base of the hernial sac. These alternatives are usually successful in obliterating the hernial sac but do not directly repair the defect in the abdominal wall.
REFERENCES 1. Adams SB, Fessler JF: Umbilical herniorrhaphy. In Adams SB, Fessler JF, editors: Atlas of equine surgery, Philadelphia, 2000, WB Saunders. 2. Freeman DE, Orsini JA, Harrison IW, et al: Complications of umbilical hernias in horses: 13 cases (1972-1986), J Am Vet Med Assoc 192:804, 1988. 3. Orsini JA: Management of umbilical hernias in the horse: treatment options and potential complications, Equine Vet Educ 9:7, 1997. 4. Wilson DA, Baker GJ, Boero MJ: Complications of celiotomy incisions in horses, Vet Surg 24:506, 1995. 5. Riley CB, Cruz AM, Bailey JV, et al: Comparison of herniorrhaphy versus clamping of umbilical hernias in horses: a retrospective study of 93 cases (19821994), Can Vet J 37:295, 1996. 6. Greenwood RES, Dugdale DJ: Treatment of umbilical hernias in foals with elastrator rings, Equine Vet Educ 5:113, 1993. 7. Freeman DE, Spencer PA: Evaluation of age, breed, and gender as risk factors for umbilical hernia in horses of a hospital population, Am J Vet Res 52:637, 1991. 8. Steckel RR, Nugent MA: Parietal hernia in a horse, J Am Vet Med Assoc 182:818, 1983. 9. Markel MD, Pascoe JR, Sams AE: Strangulated umbilical hernias in horses: 13 cases (1974-1985), J Am Vet Med Assoc 190:692, 1987.