Townsend Courtney M.Jr., Evers B. Mark. Atlas of General Surgical Techniques: Expert Consult

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747

CHAPTER

Miles Abdominoperineal

Resection with Total

Mesorectal Excision

Tien C. Ko

STEP 1: SURGICAL ANATOMY

◆ For the total mesorectal excision, please see the discussion on pelvic autonomic nerves in Chapter 64.

◆ The seminal vesicles, prostate, and urethra are located ventral to Denonvillier’s fascia cranially and

the superﬁ cial transverse perineal muscle caudally.

STEP 2: PREOPERATIVE CONSIDERATIONS

◆ Miles abdominoperineal resection with total mesorectal excision is indicated for rectal cancer near

the levator ani muscle or persistent or recurrent squamous cell cancer of the anus after chemoradia-

tion treatment.

◆ Preoperative chemoradiation treatment is indicated for T3, T4 lesions or those tumors with enlarged

pelvic lymph nodes on pelvic computed tomography (CT) scan or endorectal ultrasound.

◆ Appropriate bowel preparation such as GOLYTELY or four bisacodyl (Dulcolax) tablets followed by

HalfLytely should be administered the day before surgery. Preoperatively, a single dose of broad-

spectrum antibiotic (such as ertapenem) is administered.

◆ The permanent colostomy site is marked by an enterostomal nurse preoperatively to ensure the best

placement of the colostomy.

748 Section IX • Colon

◆ After induction of general anesthesia, the patient is placed in a lithotomy position with the

legs in padded stirrups at 30-degree abduction. The coccyx is placed near the end of the

table and elevated with a stack of towels (Figure 65-1). A nasogastric tube is placed to pre-

vent gastric distention, and a urinary catheter is placed to decompress the bladder. The

rectum is irrigated with povidone-iodine (Betadine) solution until clear. The anus is closed

with a 0 silk purse-string suture (Figure 65-2).

STEP 3: OPERATIVE STEPS

1. INCISION

◆ A midline abdominal incision is made from the pubic symphysis to approximately 5 cm

cranial to the umbilicus.

◆ The midline fascia is divided with electrocautery. The peritoneum is elevated with tissue

forceps, and after ensuring that no bowel is entrapped by the graspers, the peritoneum is

incised sharply with a scalpel.

◆ For the perineal dissection, an elliptical incision is made 2 cm away from the closed anus

(see Figure 65-2).

CHAPTER 65 • Miles Abdominoperineal Resection with Total Mesorectal Excision 749

Patient lithotomy position

FIGURE 65 –1

Midline incision

Foley catheter

Purse-string suture

closing anus

Line of incision for

perianal dissection

Coccyx

FIGURE 65 –2

750 Section IX • Colon

2. DISSECTION

◆ Once the peritoneum has been entered, a systematic exploration is performed to search for

metastases in the peritoneal cavity, including the liver and the preaortic and iliac lymph

nodes.

◆ A ﬁ xed retractor is placed to retract small bowel superiorly and laterally out of the operative

ﬁ eld. Retraction of small bowel is aided by placing the patient in a Trendelenburg position.

◆ Mobilization of the sigmoid colon is achieved by using electrocautery to incise the lateral

visceral fascia covering the mesosigmoid along the white line of Toldt, which can be easily

visualized by retracting the sigmoid colon medially (Figure 65-3). The left ureter is identi-

ﬁ ed along its course over the left iliac vessels into the pelvis.

Line of transection

through peritoneum

and mesocolon

Inferior

mesenteric

vessles

Rectum

Sigmoid colon

FIGURE 65 –3

CHAPTER 65 • Miles Abdominoperineal Resection with Total Mesorectal Excision 751

Line of peritoneal incision

for abdominoperineal

resection

Iliac vessels

Ureter

Inferior mesenteric vein

Inferior mesenteric artery

◆ The medial visceral fascia is incised with electrocautery, and the right ureter is visualized as

it courses over the right iliac vessels (Figure 65-4). The line of proximal resection is also

outlined but not carried out until the tumor is able to be fully mobilized.

FIGURE 65 –4

752 Section IX • Colon

◆ The presacral space is entered by dividing the loose areolar tissue at the level of the sacral

promontory. The presacral space is developed sharply with electrocautery caudally toward

the levator ani muscle under direct vision. A ﬁ ber-optic pelvic retractor is used for retraction

of the bladder and the rectum to facilitate visualization in the pelvis. Mobilization of the

rectum continues caudally to the levator ani muscle. After the sharp posterior pelvic dissec-

tion is completed, the distal extent of dissection can be manually evaluated (Figure 65-5).

Care must be taken to avoid injuring the presacral plexus of veins during the posterior

dissection.

FIGURE 65 –5

CHAPTER 65 • Miles Abdominoperineal Resection with Total Mesorectal Excision 753

◆ The mesorectum is mobilized laterally toward the right and left pelvic side wall, preserving the

hypogastric nerves on the sacrum. The lateral attachments to the pelvic wall containing the

mesorectum are divided either with clamps and sutures (Figure 65-6) or with a vessel-sealer

device, such as LigaSure.

◆ The rectum is mobilized ventrally by dividing the rectovaginal septum or the rectovesicle

space. In males, the dissection plane is ventral to Denonvillier’s fascia, preserving the

seminal vesicles.

◆ Attention is directed toward the resection of proximal sigmoid colon. First, the inferior

mesenteric artery is divided just distal to the origin of the left colic artery either with

clamps and sutures or with a vessel-sealer device. Next, the proximal sigmoid colon is

divided with a gastrointestinal anastomosis (GIA) stapler (Figure 65-7).

GIA stapler used for

transection of proximal

sigmoid colon

FIGURE 65 –7

Division of lateral

attachments

FIGURE 65 –6

754 Section IX • Colon

◆ A colostomy site is created in the left lower quadrant at either the premarked site or

halfway between the umbilicus and the left anterior superior iliac spine. A 2 cm in diameter

circle of skin is excised with a scalpel, and the subcutaneous tissue is divided with electro-

cautery. A cruciate incision is made in the anterior rectus abdominis fascia, and 2 cm of the

rectus abdominis muscle is divided with electrocautery. The peritoneum is incised with

electrocautery to complete the colostomy site, which should be approximately 2 ﬁ nger-

breadths in diameter.

◆ The perineal dissection may be performed sequentially or simultaneously by a second team.

After skin incision, the laterally ischiorectal space is entered. The skin and subcutaneous

tissue is retracted with a self-retaining retractor to facilitate deep dissection (Figures 65-8

and 65-9). Inferior hemorrhoidal vessels are secured with sutures and divided. The coccyx

is identiﬁ ed posteriorly, and the anococcygeal ligament located posteriorly is divided. Later-

ally, the levator ani muscle is divided with electrocautery and the perineal fossa is entered.

◆ The distal stump of the transected sigmoid colon and the proximal rectum is delivered cau-

dally through the opening of the levator ani muscle (Figure 65-10). Ventral mobilization of

the rectum is facilitated by the anterior retraction of the skin and subcutaneous tissue and

the posterior retraction of the sigmoid colon and rectum. The superﬁ cial transverse perineal

muscle is divided with electrocautery to completely mobilize the rectum. In males, the ure-

thra courses ventrally to the superﬁ cial transverse perineal muscle and can be identiﬁ ed and

protected by palpating the urinary catheter. The sigmoid colon and rectum are removed

through the perineal wound.

Line of incision for

perianal dissection

FIGURE 65 –8

CHAPTER 65 • Miles Abdominoperineal Resection with Total Mesorectal Excision 755

Levator ani muscle

and vessels

Perineal fossa

Ligated hemorrhoidal

vessels

FIGURE 65 –9

Transected stump of sigmoid colon

and proximal rectum drawn through

opening in levator ani muscle and

peritoneum

FIGURE 65 –10

756 Section IX • Colon

3. CLOSING

◆ The pelvis is irrigated with saline, and hemostasis is obtained. Two Silastic 10-mm drains

are placed in the pelvis through stab incisions in the right and left gluteal regions, lateral to

the perineal wound, and secured with sutures of 2-0 nylon. The levator ani muscle is reap-

proximated with a running suture of 2-0 Vicryl (Figure 65-11).

◆ The subcutaneous tissue of the perineum is reapproximated with a running suture of

3-0 Vicryl. The skin is closed with interrupted vertical mattress sutures of 2-0 nylon

(Figure 65-12). The perineal incision is covered with povidone-iodine ointment and

nonadhesive gauze.

◆ A pedicle of the greater omentum is mobilized from the transverse colon and placed into

the pelvis to promote healing and prevent small bowel adhesions in the pelvis (Figure

65-13). The proximal end of the resected colon is brought through the colostomy site, and

the serosa of the colon is secured to the peritoneum with several interrupted sutures of

3-0 silk.

◆ The midline abdominal incision is closed by reapproximating the fascia in one layer with

two running absorbable sutures of loop 0 polydioxanone (PDS), beginning at the cranial

and caudal end of the incision. The skin is reapproximated with staples.

◆ The colostomy is matured by ﬁ rst removing the staple line with electrocautery. The full-

thickness colonic mucosa is sutured to the dermis of the colostomy site circumferentially

with interrupted sutures of 3-0 Monocryl. The colostomy is covered with a stoma

appliance.

◆ The nasogastric tube is removed before the patient awakes from anesthesia.