Carcinoma of the Ampulla of Vater
Synonyms and related keywords: periampullary carcinoma, periampullary malignancy, ampullary carcinoma, ampullary cancer, carcinoma of papilla of Vater, adenocarcinomas, neuroendocrine tumors, cystadenomas, adenomas, adenocarcinoma of the ampulla of Vater, Courvoisier sign, familial adenomatous polyposis, FAP, duodenal adenomas, endoscopic ultrasonography, EUS, endoscopic retrograde cholangiopancreatography, ERCP, percutaneous transhepatic cholangiography, PTC, kocherization, pancreaticoduodenectomy, pylorus-preserving pancreaticoduodenectomy, transduodenal excision
INTRODUCTION
- Surgical morbidity rates remain high, with a range of 25-65%, even in centers with experienced staff. Pancreatic fistulas, prolonged gastric emptying, wound complications, intraabdominal sepsis, thrombophlebitis, and marginal ulceration are the most common complications.
- Postoperative mortality rates in the best centers are 2-5%.
CLINICAL
DIFFERENTIALS
Ascariasis
Bile Duct Strictures
Bile Duct Tumors
Biliary Disease
Biliary Obstruction
Cholangiocarcinoma
Choledocholithiasis
Duodenal Ulcers
Gallbladder Cancer
Gallbladder Tumors
Lymphoma, Non-Hodgkin
Pancreatic Cancer
Pancreatitis, Chronic
Papillary Necrosis
Papillary Tumors
Other Problems to be Considered:
Duodenal carcinoma
Adenoma at the ampulla of Vater
WORKUP
- Advantages
- Abdominal ultrasonography (US) is the most useful noninvasive initial investigation for distinguishing medical from surgical causes of jaundice. It is an inexpensive and readily available bedside procedure.
- Abdominal US can identify dilated ducts, liver metastasis (in almost 90% of cases), ascites, and nodal metastasis.
- Doppler US can be used to assess vascular involvement.
- The level of obstruction can be assessed in 90% patients.
- US-guided fine-needle aspiration (FNA) can be performed.
- Limitations
- Effectiveness is related to the skill of the user.
- Very superficial lesions and very deep lesions may be missed. Distinguishing a metastasis from a hemangioma may be difficult.
- Sensitivity is 80–90%, and information is inferior to that obtained by CT scan or MRI. Poor bowel preparation may obscure the important pathology.
- Endoscopic ultrasonography (EUS) is performed through a peroral route.
- The test is highly sensitive in detecting major vascular involvement, which can prevent unnecessary surgery (Menzel, 1999).
- EUS may identify tumors less than 1 cm in size.
- Laparoscopic sonography can detect occult liver metastasis or peritoneal seeding missed by other imaging modalities.
- Staging laparoscopy with laparoscopic ultrasonography may be more specific and accurate in predicting tumor resectability than laparoscopy alone (88% and 89% vs 50% and 65%, respectively; John, 1995).
- Advantages
- This modality is most useful when US is equivocal or when visualization is obscured by gas or ascites.
- CT scan is superior to US, with an accuracy of more than 90%. CT scan findings correlate well with operative findings.
- CT scan is better in evaluating operability and preoperative staging. It gives better assessment of invasion or compression of vessels and adjacent organs.
- CT-guided biopsy may be obtained.
- Disadvantages
- Very ill patients may be unable to lie still or arrest respiration for the long periods required for high-quality imaging.
- CT scan is more expensive than US and requires expertise in interpretation.
- Potential radiation hazards exist for patients and staff.
- Rare contrast reactions may occur.
- Metal, stents, and clips may cause artifacts.
- Very small tumors (less than 1 cm) may be missed.
- MRI is the most informative noninvasive method of evaluation currently available.
- MRI cholangiopancreatography (MRCP) provides 94% accuracy in identifying the cause and extent of the pathology.
- Results are reproducible.
- With growing expertise in the use of magnetic imaging, diagnostic endoscopic retrograde cholangiopancreatography (ERCP) is quickly becoming obsolete.
- ECG is performed to assess cardiac status, since surgery will be considered as a means of treatment.
- Advantages
- ERCP allows diagnostic and therapeutic access to both the common bile duct and pancreatic duct.
- The procedure displays the details of ductal anatomy and accurately demonstrates the level and nature of the obstruction. Anatomical variations in ducts can be evaluated carefully.
- ERCP allows therapeutic procedures, eg, sphincterotomy, stenting, and nasobiliary drainage.
- It permits sampling of pancreatic juice, bile, and brush/grasp biopsy.
- Endoscopic excision of small periampullary tumors is gaining in popularity.
- Disadvantages
- ERCP is an invasive procedure, which requires an expert endoscopist/radiologist and a cooperative patient.
- Very small tumors (less than 1 cm) can be missed.
- ERCP is not possible if access to the duodenal papilla is difficult, eg, owing to diverticula, anatomical ductal variations, or prior surgical bypass.
- This procedure can precipitate pancreatitis and cholangitis.
- Perforation and hemorrhage are 2 of the more serious complications.
- Percutaneous transhepatic cholangiography
- Indications for this procedure, which is highly invasive, are very limited.
- Percutaneous transhepatic cholangiography (PTC) is most useful when ERCP is unavailable or technically not feasible.
- PTC can be useful in severely jaundiced patients when laparotomy or ERCP is not possible. Percutaneous transhepatic biliary drainage or transhepatic stenting may be the only option for some patients.
- Biliary leakage may lead to peritonitis. Excessive bleeding from the puncture site and pneumothorax represent significant, but uncommon, complications.
Staging: The tumor, node, metastases (TNM) classification and stage grouping is based on the Union Internationale Contre Cancrum (UICC) system, established in 1977, with separate classifications for pancreatic and periampullary carcinomas. The staging is important only to communicate a uniform definition of extent of disease. TNM classification and stage groups are as follows:
- T - Primary tumor
- Tx - The primary tumor cannot be assessed
- T0 - No sign of primary tumor
- Tis - Carcinoma in situ
- T1 - Tumor limited to the ampulla or sphincter of Oddi
- T2 - Tumor invading the wall of the duodenum
- T3 - Tumor invasion into the pancreas 2 cm or less
- T4 - More than 2 cm tumor invasion into the pancreas or any other adjacent organ
Peripancreatic tissue includes the surrounding retroperitoneal fatty tissue (retroperitoneal soft tissue or retroperitoneal space), including the mesentery (mesenteric fat), mesocolon, greater and lesser omentum, and peritoneum. Direct invasion of the bile ducts and the duodenum includes involvement of the ampulla.
Adjacent large vessels include the portal vein, the celiac trunk, the superior mesenteric artery and the common hepatic artery and vein (not the splenic vessels).
- N - Regional lymph nodes
- NX - Regional lymph nodes cannot be assessed
- N0 - No regional lymph node metastases
- N1 - Regional lymph node metastases
Subclassification of the category N1 into N1a (only 1 metastatic lymph node) and N1b (2 or more lymph nodes affected by metastases) is recommended, as the 2 categories appear to have marked prognostic differences. Total number of peripancreatic lymph nodes found in the surgical specimen must be mentioned.
- M - Distant metastases
- MX - Distant metastases cannot be assessed
- M0 - No distant metastases
- M1 - Distant metastases
Note: The splenic lymph nodes and those at the tail of the pancreas are not regional; metastases in these lymph nodes are classified as distant metastases (M1).
- Stage grouping of periampullary carcinoma
- Stage 1 - T1 N0 M0
- Stage 2 - T2 N0 M0, T3 N0 M0
- Stage 3 - T1 N1 M0, T2 NI M0, T3 N1 M0
- Stage 4 - T4 every N and every M, Every T and N with M1
- Martin proposed a 4-stage system, as follows:
- Stage I - Vegetating tumor limited to the epithelium, with no involvement of the Oddi sphincter
- Stage II - Tumor localized in the duodenal submucosa without involvement of the duodenal muscularis propria but possible involvement of the sphincter of Oddi
- Stage III - Tumor involving the duodenal muscularis propria
- Stage IV - Tumor involving the periduodenal area or the pancreas, with proximal or distal lymph node involvement
TREATMENT
- Gemcitabine has shown promise in cases of advanced ampullary carcinoma.
- Fractionated high-dose external beam radiotherapy (60-70 Gy) yields local tumor control in 35-50% of cases. Care should be taken to protect healthy tissue while delivering this radiotherapy (ie, conformal RT or brachytherapy).
- Pain can be relieved in as many as 65% of patients treated with external beam radiotherapy.
- Surgical resection in an ampullary carcinoma is the primary modality of treatment. The highest cure rates are achieved if the tumor is localized to the ampullary region.
- Laparotomy should be performed to assess resectability in all cases for which sonography, CT scan, and laparoscopy do not show disseminated disease.
- With improvement in postoperative management and surgical technique, operative mortality rates are as low as 3-5% in most centers with experienced staff (Wagle, 2001).
- Extensive preoperative assessment of cardiac, respiratory, renal, and cerebral functions should be performed in older patients.
- Overall survival rates are better for ampullary carcinoma than for other periampullary malignancies, because the former disease typically manifests symptoms early.
- Tok et al reported 25 patients (13 men, 12 women) with a median age of 65 years who had an ampullary tumor. The resectability rate was 88%, with no operative mortality. The 5-year actuarial survival rate of patients who underwent radical resection was 49%. They concluded that local resection is recommended only for small, benign tumors and for patients who may be unfit for radical surgery; otherwise, pylorus-preserving pancreaticoduodenectomy is safe and the most effective procedure.
- Assessment of nutritional status and supplementation (Fortunately, most of these patients do not have any nutritional problems.)
- Standard mechanical and oral antibiotic bowel preparation
- Assessment of coagulation profile and correction of decreased prothrombin time by administration of vitamin K
- Intravenous antibiotic prophylaxis
- Preoperative nasobiliary drainage or stenting for preoperative biliary decompression in severely jaundiced patient
- Fluid and electrolyte correction
- Assessment of cardiac, renal, and pulmonary status
- Laparoscopic assessment is obtained for peritoneal metastasis, hepatic metastases, and extensive lymphatic, vascular, or surrounding organ invasion.
- Resectability of the primary tumor is determined by mobilizing the head of the pancreas (ie, kocherization), opening the lesser sac, and exposing and inspecting the confluence of the splenic vein and superior mesenteric vein. Invasion of the retropancreatic portal vein is not a universal contraindication, as this segment of portal vein may be resected en bloc and subsequent reanastomosis of the vein performed.
- Intraoperatively, a transduodenal FNA or core biopsy is the preferred method for pathologic confirmation of the diagnosis. In about 10% of cases, these methods do not permit intraoperative confirmation of carcinoma. Resection should be performed in such cases based on preoperative and intraoperative findings.
- Resectability may be a subjective phenomenon based on the experience and skill of the surgeon (Sohn, 1999).
- A feeding jejunostomy may be performed during the procedure to permit early resumption of enteral feeding. This rarely is necessary, as most patients can resume an oral diet within 2-3 days.
- Pancreaticoduodenectomy
- This is the classic and standard resection procedure for ampullary carcinoma.
- In this operation, the pancreas is transected to the left of the portal vein, along with the uncinate process (in order to achieve lymph node dissection along the superior mesenteric artery). The lymph nodes along the common hepatic artery within the hepatoduodenal ligament and the precaval lymph nodes are removed. The gallbladder, along with the distal portion of the common bile duct and distal third of the stomach, is resected.
- Restoration of the gastrointestinal continuity is completed with pancreaticojejunostomy, hepaticojejunostomy, and gastrojejunostomy.
- Pylorus-preserving pancreaticoduodenectomy
- This preserves the entire pylorus, along with 1-2 cm of the first part of the duodenum. GI continuity is restored with a duodenojejunostomy.
- This represents a more physiologically acceptable procedure, with similar survival rates. Postgastrectomy complications, such as dumping and marginal ulceration, are reduced. Delayed gastric emptying may be exacerbated.
- Postprandial release of gastrin and secretin is nearly normal in patients who undergo this procedure.
- Transduodenal excision of ampullary tumors
- Transduodenal excision rarely is indicated and is reserved for elderly patients, patients with significant comorbid conditions, and those with favorable tumors (generally less than 2 cm, polypoid).
- This more limited resective technique is associated with compromised local control in many instances.
- Palliative surgery
- Palliative surgery is reserved for unresectable tumors or for patients who are unfit for curative surgery.
- The goal is to alleviate biliary obstruction, duodenal obstruction, or pain.
- Either cholecystojejunostomy or hepaticojejunostomy bypass is performed.
- Duodenal obstruction may require gastrojejunostomy. Prophylactic gastrojejunostomy should be done, even in a duodenum unobstructed at the time of laparotomy, because as many as one third of patients develop obstruction later. However, prophylactic gastrojejunostomy adds significant morbidity risk to the procedure.
- Chemical splanchnicectomy, using either 6% phenol or 50% ethanol, can be performed intraoperatively. This procedure controls pain in 80% of patients.
Consultations:
- A nutrition specialist for tailoring the diet, when needed
- Physiotherapist
- Physician in cases of postoperative fever, chest infection, or other problems
Diet:
- Oral feeding usually can be started on the second postoperative day.
- The diet should be started with sips of water, which can be increased gradually over 48 hours to a liquid diet. Patients can have a semisolid diet by roughly the sixth day.
- Initially, the diet should be deficient in fat and protein.
Activity:
- The patient should ambulate from the first postoperative day.
- Early ambulation and chest physiotherapy reduce morbidity.
MEDICATION
Prophylactic and postoperative antibiotics are given according to hospital protocol.
Drug Name | Fluorouracil (Adrucil) -- Fluorinated pyrimidine antimetabolite that inhibits thymidylate synthase and interferes with RNA synthesis and function. Has some effect on DNA. Useful in symptom palliation for patients with progressive disease. |
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Adult Dose | 500 mg/m2 IV |
Pediatric Dose | Not established |
Contraindications | Documented hypersensitivity; bone marrow suppression; serious infection |
Interactions | Increased risk of bleeding with anticoagulants, NSAIDs, platelet inhibitors, thrombolytic agents; other immunosuppressive agents may enhance bone marrow toxicity |
Pregnancy | D - Unsafe in pregnancy |
Precautions | Nausea, oral and GI ulcers, depression of immune system, and hematopoiesis failure (bone marrow suppression) may occur; adjust dose in renal impairment |
Drug Name | Cefoxitin (Mefoxin) -- Second-generation cephalosporin indicated for gram-positive cocci and gram-negative rod infections. Infections caused by cephalosporin- or penicillin-resistant gram-negative bacteria may respond to cefoxitin. Any second-generation cephalosporin may be used instead of cefoxitin. |
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Adult Dose | Biliary stent present: 1 g IV preoperatively; continue until culture reported negative; if positive, adjust antibiotics on basis of culture sensitivity report No biliary stent: 1 g IV preoperatively then 2 doses postoperatively |
Pediatric Dose | Not established |
Contraindications | Documented hypersensitivity |
Interactions | Probenecid may increase effects aminoglycosides or furosemide may increase nephrotoxicity (closely monitor renal function) |
Pregnancy | B - Usually safe but benefits must outweigh the risks. |
Precautions | Adjust dose in severe renal insufficiency (high doses may cause CNS toxicity); superinfections and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy |
FOLLOW-UP
MISCELLANEOUS
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