Intestinal Surgery

DUODENOTOMY

SURGICAL CONSIDERATIONS

Description: A duodenotomy is performed to ligate a bleeding vessel at the base of a duodenal ulcer or to perform some procedure on the ampulla of Vater or the duct of Santorini or to remove a low-grade duodenal tumor. It is important, therefore, to be familiar with the anatomy of the proximal duodenum in relation to the major and minor pancreatic duct orifices (Fig. 7.3-1). The duodenotomy may be made longitudinally or transversely, depending on the surgeon’s preference. A transverse opening allows one to close the duodenotomy without tension; however, it must be made very accurately for the purpose of exposure. Therefore, a longitudinal duodenotomy is preferred. With mobilization it can be closed transversely. Bleeding vessels at the base of an ulcer must be secured with suture ligatures. Care must be taken to avoid perforating the duodenum when performing a sphincterotomy.

Usual preop diagnosis: Duodenal ulcer; impacted common duct stone; chronic pancreatitis 2° alcoholism, gallstones, pancreatic divisum, or other obstruction of the main pancreatic duct, benign ampullary tumor, duodenal neuroendocrine tumor.

▪ SUMMARY OF PROCEDURE

Position	Supine
Incision	Midline abdominal or subcostal
Unique considerations	Magnifying glasses, if operation involves lesser pancreatic sphincter
Antibiotics	Cefoxitin 1-2 g iv
VTE prophylaxis	Heparin 5000 units sq
Surgical time	1-2 h
Closing considerations	Secure closure of duodenum without tension usually two layers
EBL	Minimal
Postop care	± NG decompression
Mortality	< 0.5%
Morbidity	Duodenal leak: < 2% Postop pancreatitis: < 3%
Pain score	6-8

Figure 7.3-1. Anatomy of pancreatic ductal system. In 30% of patients, the accessory duct ends blindly. (Reproduced with permission from Greenfield LJ, Mulholland MW, Oldham KT, et al: Surgery: Scientific Principles and Practice, 3rd edition. Lippincott Williams & Wilkins, Philadelphia: 2001.)

ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations following Operations for Peptic Ulcer Disease, Stomach Surgery, p. 527.

Suggested Reading

1. Cisco RM, Norton JA: Surgery for gastrinoma. Adv Surg 2007; 41:65-76.

OPEN APPENDECTOMY

SURGICAL CONSIDERATIONS

Description: Open appendectomy is performed for appendicitis or suspected appendicitis; however, it has been largely replaced by the laparoscopic approach (see p. 611). The negative laparotomy rate has been reduced by the judicious use of preoperative CT examination. Through a RLQ (McBurney) or right paramedian incision, the cecum is exposed and pulled into the wound (Fig. 7.3-2). The appendix is then delivered through the wound; and the mesoappendix is clamped, cut, and ligated. The appendix is removed by crushing, ligating, and then transecting the base. The appendiceal stump may be invaginated into the wall of the cecum or left alone. In some instances it may be easier to divide the base of the appendix before delivering the appendix into the wound. The wound should be left open and soft drains used in cases of perforated appendix. In children, the appendix may be inverted and allowed to slough off internally. In laparoscopic procedures, the appendix is usually transected with an endoscopic stapling device. This method is also being used in open procedures.

Variant procedure or approach: Laparoscopic appendectomy (see p. 606).

Figure 7.3-2. Relevant anatomy for appendectomy. (Reproduced with permission from Scott-Conner CEH, Dawson DL: Operative Anatomy, 2nd edition. Lippincott Williams & Wilkins, Philadelphia: 2003.)

Usual preop diagnosis: Appendicitis

▪ SUMMARY OF PROCEDURE

Position	Supine
Incision	RLQ (McBurney’s) or right paramedian
Unique considerations	Variation in stump closure; NG tube if prolonged ileus expected.
Antibiotics	Cefoxitin 1-2 g preop
VTE prophylaxis	Heparin 5000 units sq
Surgical time	1 h
Closing considerations	Skin wound should not be closed when appendix is perforated. Drain in presence of well-defined abscess cavity.
EBL	< 75 mL
Postop care	Wound care when left open
Mortality	Perforated: 2% Nonperforated: < 0.1%
Morbidity	Pelvic, subphrenic, or intraabdominal abscess (perforation): 20% Wound abscess: < 5% Fecal fistula: < 1% Wound hematoma: < 0.5% Ileus: Variable
Pain score	5-7

ANESTHETIC CONSIDERATIONS

See Anesthetic Consideration following Excision of Meckel’s diverticulum, below p. 524.

Suggested Readings

1. Nguyen NT, Hinojosa MW, Fayad C, et al: Laparoscopic surgery is associated with a lower incidence of venous thromboembolism compared with open surgery. Ann Surg 2007; 246:1021-7.

2. See Suggested Readings following Excision of Meckel’s diverticulum, pp. 525-526.

EXCISION OF MECKEL’S DIVERTICULUM

SURGICAL CONSIDERATIONS

Description: Meckel’s diverticulum is a true congenital diverticulum, usually arising within 100 cm of the ileocecal valve. It was first described by Meckel in 1809. Excision of a Meckel’s diverticulum is indicated for bleeding, obstruction, perforation, inflammation, intussusception, and when there is a palpable mass near the base of the diverticulum. Ectopic mucosa is present in roughly 50% of symptomatic patients, with gastric mucosa the most frequent. After entering the peritoneal cavity, the distal ileum, along with the diverticulum, is delivered into the wound. The diverticulum is excised, and the wound is closed in two layers. Following excision of the diverticulum, care must be taken not to narrow the bowel lumen during closure. If a diagnosis can be made preop, a laparoscopic approach may be used (see Laparoscopic Bowel Resection p. 602).

Usual preop diagnosis: Meckel’s diverticulum

ANESTHETIC CONSIDERATIONS

(Procedures covered: open appendectomy; excision of Meckel’s diverticulum)

PREOPERATIVE

This patient population is generally fit and healthy, apart from their acutely presenting illness. These patients are at risk for aspiration pneumonitis due to delayed gastric emptying, ileus, or frank bowel obstruction → full stomach precautions are appropriate. Surgery for appendicitis is one of the most common nonobstetric procedures performed on the pregnant patient (˜1/1500 pregnancies). These patients often are more ill at the time of diagnosis because early symptoms may be attributed to pregnancy, and the gravid uterus may hinder an accurate abdominal exam. Anesthesia management for the gravid appendicitis patient mirrors that of the nongravid patient (full-stomach precautions) with consideration of the maternal physiologic changes of pregnancy and the effects of anesthesia on the fetus and uteroplacental perfusion (See Anesthetic Considerations for Cervical Cerclage, Obstetric Surgery, p. 853.)

Respiratory	Respiratory impairment may occur 2° the acute abdominal pain and splinting. Tachypnea and hyperpnea can be heralding Sx of appendiceal perforation and sepsis. Patients with an acute abdomen should be treated as if they have full stomachs. Consider administration of metoclopramide (10 mg iv), H₂-antagonist (ranitidine 50 mg iv), and Na citrate 0.3 M 30 mL po. Tests: As indicated from H&P
Cardiovascular	May be dehydrated from fever, emesis, and ↓ oral intake → ↑ HR + ↑ BP (2° pain), or ↓ BP (sepsis, hypovolemia). Assess volume status appropriately and hydrate adequately prior to proceeding with anesthetic induction. Tests: ECG, if indicated from H&P
Gastrointestinal	Patient typically has abdominal pain with N/V. Muscular resistance to palpation of abdominal wall frequently parallels the severity of the inflammatory process. With spreading peritoneal irritation (as with perforation), patient will develop abdominal distension and paralytic ileus. Electrolyte abnormalities are common 2° N/V. Tests: Electrolytes
Hematologic	Moderate leukocytosis (10,000-18,000) with moderate left shift. Hemoconcentration is probable if patient is dehydrated. Tests: CBC
Laboratory	Other tests as indicated from H&P
Premedication	Full-stomach precautions (see p. B-5). Consider midazolam 1-2 mg iv. Opiate medications (morphine 0.03-0.15 mg/kg iv) often delayed or minimized until diagnosis made. Opiate analgesics not contraindicated during the evaluation of an acute abdomen including appendicitis.

INTRAOPERATIVE

Anesthetic technique: GETA, with rapid-sequence iv induction, followed by ET intubation (see full-stomach precautions, p. B-5). If systemic sepsis is absent, hydration is adequate, the patient is cooperative, and high abdominal exploration is unlikely, then regional anesthesia may be considered for open procedures.

Induction	Rapid-sequence induction of anesthesia (see p. B-5). Restore intravascular volume prior to anesthetic induction if patient is hypovolemic.
Maintenance	Standard maintenance (see p. B-3), without N₂O. Evacuate stomach with OG or NG tube. Maintain muscle relaxation based on nerve stimulator response.
Emergence	Patient should be extubated awake after return of airway reflexes.
Blood and fluid requirements	IV: 16-18 ga × 1 NS/LR @ 5-8 mL/kg/h
Monitoring	Standard monitors (see p. B-1).	Others, as indicated by patient’s status.
Positioning	[check mark] and pad pressure points [check mark] eyes
Complications	Sepsis