Malignant bowel obstruction is a common event in patients with locally advanced cancers, reaching an incidence of 28 % in GI cancer and 51 % in OC [1, 2]. Symptoms are related to the level of obstruction and usually include severe abdominal pain and distension, nausea, vomiting, and inability to pass gas and stool [52]. In patients with advanced or end-stage digestive or gynecological cancers, the onset of bowel obstruction may be insidious, evolving over several weeks and presenting spontaneous remissions between acute relapses [53]. Malignant bowel obstruction may have both mechanical and functional origin: the former is related to direct compression or infiltration by tumor masses of bowel loops, and the latter is related to impaired intestinal motility, resulting from tumor infiltration of mesenteries, nerves involved in intestinal motility, massive ascites, or chronic opioid therapies. Computed tomography is the gold standard for diagnosing malignant bowel obstruction, as it has a specificity and sensitivity > 90 % [54]. CT can exclude nonneoplastic causes of obstruction, which can occur in 15–30 % of patients with carcinomatosis and are mostly related to adhesions, hernias, and eventration [55, 56]. It can also identify the presence of a surgical emergency, such as perforation, volvulus, or strangulation, all of which are surgical indications even for palliative care. Decision making is very difficult in these patients. Medical conservative treatment is often not effective to relieve symptoms, and major surgical procedures should be avoided in patients who have limited life expectancy and who are poor surgical candidates because of malnutrition and underlying disease [57]. A large review by Laval et al. proposed recommendations and practical clinical guidelines to guide decision making, reserving surgery for patients with nonneoplastic mechanical obstruction, emergency situations, and limited obstruction with no indications to endoscopic prosthesis. Conservative medical management is preferred for patients with single stenosis suitable for endoscopic treatment, in poor general condition, or with extensive carcinomatosis, multiple areas of stenosis, or mesentery-root invasion. Age, comorbidities, nutritional status, previous radiotherapy, and level of obstruction are also identified as poor prognostic factors for surgical treatment [52] (Table 23.2).

Conservative management of patients with malignant bowel obstruction includes fasting, intravenously delivered rehydration, total parenteral nutrition, nasogastric tube (NGT) placement, and antiemetic, antisecretory, analgesic, and corticosteroid drug administration. Antisecretory drugs, which reduce digestive secretions such as octreotide, are particularly important in relieving patient distress; if vomiting does not stop, a venting gastrostomy rather than long-term NGT may be considered [52]. Endoscopic prosthesis must be preferred to surgery when technically possible due to its lower morbidity and mortality rates; PC must not be considered a contraindication to stent placement in patients with a single-site bowel obstruction [58]. Complications are rare and include perforation (0.5–4 %) and stent migration (8–12 %) and obstruction (0.5–10 %). Technical failure is more frequent in long-standing stenosis [59].

A surgical approach should be carefully considered when conservative treatment fails or is not possible. Surgical procedures include ostomies (colostomy, ileostomy, jejunostomy), small- or large-bowel resections and/or bypass, and lysis of either malignant or inflammatory adhesions. Surgical strategy is determined upon intraoperative findings, and no standard guidelines are available. Several studies demonstrated benefits in symptoms relief with resumption of oral intake after palliative surgery for malignant bowel obstruction in 32–100 % of patients [60–66]. QoL measures are not reported by any available study. The literature reports that perioperative morbidity and mortality and rates are high, ranging from 7 % to 44 % and from 6 % to 32 %, respectively [60–62, 65, 67–69]. A frequent complication, occurring in from 6 % to 47 % of patients, is reobstruction [61–63, 66, 69]. Furthermore, duration of symptom relief may be short [66, 69] and hospital stay considerable in relation to patients life expectancy, which ranges from 1 to 94 days [70]. When obstructive symptom resolution is achieved and is long lasting, survival advantage may be significant, rising from 26 to 36 days to 154 to 192 days in some series [62, 71]. Table 23.3 summarizes the most relevant experiences and results in surgical treatment of malignant bowel obstruction in patients with PC. Authors experience is detailed in Table 23.4: overall median survival was 96.1 days (OC 100.3 days, GI cancer 83.5 days, CRC 104.5 days), and mean hospital stay was 9.6 days (range 6–14). Operative mortality occurred in two patients (17 %): one died after reoperation for bleeding, and reobstruction occurred in one, who died after 28 days.