Postoperative changes, complications, and recurrent disease after Whipple's operation: CT features

The Diagnostic Performance of 18F-FDG PET/CT in Recurrent Pancreatic Cancer: A Systematic Review and Meta-analysis

Purpose

The CT scan is the best common screening test for pancreatic cancer recurrence after surgery. The goal of our meta-analysis was to assess the diagnostic accuracy of 18F-FDG PET/CT for pancreatic cancer recurrence.

Methods

We examined PubMed and Embase for suitable papers between 2009 and 2022. The researchers considered studies that looked at the diagnostic usefulness of 18F-FDG PET/CT in identifying local and/or distant disease recurrence throughout the follow-up following pancreatic cancer resection. The Quality Assessment of Diagnostic Performance Studies-2 (QUADAS-2) method was used to evaluate the quality of each study. For each of the publications included, two researchers extracted data independently. The extracted data included general data (authors, year of publication), literature characteristics (country, type of literature, and design of study), characteristics of the patient (patients' number, mean or median age, and treatment regimen), and technical aspects (scanner, injection activity, and image analysis).

Results

The analysis includes 7 trials with a total of 263 patients. The sensitivity and specificity of 18F-FDG PET/CT in detecting recurrent pancreatic cancer following definitive treatment were 0.89 (95 percent CI: 0.83-0.93) and 0.88 (95 percent CI: 0.72-0.96), respectively, according to the pooled estimates. PET/CT performed well in the diagnosis of recurrent pancreatic cancer, with an AUC of 0.94. (0.91-0.95).

Conclusions

18F-FDG PET-CT was found to be a reliable detection method in recurrent pancreatic tumor.

C-reactive protein identifies patients at risk of postpancreatectomy hemorrhage

Background

Postpancreatectomy hemorrhage grade C (PPH C) is a dreaded complication after pancreaticoduodenectomy (PD) with high mortality rate. Concurrent risk factors for PPH C have been difficult to recognize. Connection between postoperative pancreatic fistulas (POPF) and PPH C is well known, but POPF is often unknown prior to the PPH. The aim of this retrospective study was to define potential predictive factors for PPH C.

Methods

Retrospectively, 517 patients who underwent PD between 2003 and 2018 were included in the study. Twenty-three patients with PPH C were identified, and a matched control group of 92 patients was randomly selected. Preoperative data (body mass index, cardiovascular disease, history of abdominal surgery, biliary stent, C-reactive protein (CRP), ASA-score), perioperative data (bleeding, pancreatic anastomosis, operation time), and postoperative data (CRP, drain amylase, POPF, biliary fistula) were analyzed as potential predictors of PPH C.

Results

High postoperative CRP (median 140 mg/L on day 5 or 6) correlated with the development of PPH C (p < 0.05). Postoperative drain amylase levels were not clinically relevant for occurrence of PPH C. Grade C POPF or biliary leak was observed in the majority of the PPH C patients, but the leaking anastomoses were not detected before the bleeding started.

Discussion

High postoperative CRP levels are related to an increased risk of PPH C.

Pathological Features and Imaging Findings in Pancreatic Carcinoma In Situ

OBJECTIVES

This study aimed to evaluate the pathological features and imaging findings of pancreatic carcinoma in situ (PCIS).

METHODS

Twenty patients with PCIS were categorized as flat (F) (n = 6) and low papillary (LP) (n = 14) types.

RESULTS

None of F type and 8 (57%) of 14 with LP type lesions showed intraductal infiltrations of the main pancreatic duct (MPD) greater than 10 mm. None of F type and 3 (21%) of 14 with LP type lesions showed skip lesions in the MPD. Magnetic resonance cholangiopancreatography showed irregular MPD stenoses in 5 (83%) of 6 with F and 13 (100%) of 13 with LP type lesions. Magnetic resonance cholangiopancreatography determined that the median lengths of the irregular MPD stenoses were 3.6 mm for F, and 11.6 mm for LP type lesions. Endoscopic retrograde cholangiopancreatography determined that the median lengths of the irregular MPD stenoses were 2.8 mm for F, and 14.3 mm for LP type lesions. Pancreatic cancer recurrences limited to the remnant pancreas occurred in 2 patients with LP type lesions.

CONCLUSIONS

In LP type PCIS, intraductal infiltration of the MPD occurs frequently. There may be multiple lesions, and lesions may recur in the remnant pancreas. Long-term strict follow-up assessments should be implemented for LP type PCIS.

Value of endoscopic ultrasonography in the observation of the remnant pancreas after pancreatectomy

BACKGROUND

Endoscopic ultrasonography (EUS) is proven to be a more specific and sensitive method for detecting pancreatic lesions. However, usefulness of EUS after pancreatectomy has not been reported. This study aimed to evaluate the observational capability of EUS for the remnant pancreas (RP) after pancreatectomy.

PATIENT AND METHODS

This single-center, retrospective study enrolled 395 patients who underwent pancreatectomy at Onomichi General Hospital between December 2002 and March 2016, 45 patients who underwent EUS for RP were included for analysis. We evaluated the usefulness of EUS for RP using logistic regression analysis.

RESULTS

Complete observation of the RP was done in 42 patients (93%). In the initial surgical procedure, 21 patients underwent pancreaticoduodenectomy (PD), and 24 patients underwent distal pancreatectomy (DP). PD and DP were observed in 85% (18/21) and 100% (24/24) cases, respectively. A comparison of the detection capability of EUS and contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) showed that EUS was significantly superior to contrast-enhanced CT or MRI (p < 0.01). Eight of the 45 patients showed recurrence lesions in the RP. The median recurrence period was 33 months. Predictive factors for recurrence in the univariate and multivariate analyses were significantly different in space occupying lesion with EUS findings (p < 0.01) and elevated CA19-9(p < 0.01).

CONCLUSIONS

EUS was able to observe the RP in almost all cases. In addition, the detection capability of EUS was significantly superior to those of CT or MRI. We recommend that all patients with RP should undergo EUS, and a longer follow-up must be performed.

Frequency and causes of delayed diagnosis of visceral artery pseudoaneurysms with CT: Lessons learned

Objective

Visceral artery pseudoaneurysms (VAPA) are associated with a high morbidity and mortality, but sometimes are missed in initial computed tomography (CT) examinations. The aims of this study were to determine the frequency and causes of misdiagnoses of VAPA with CT.

Materials and Methods

We retrospectively identified 77 patients with VAPA in our database who underwent contrast-enhanced CT. The frequency of delayed diagnosis was determined and the reasons were noted. We identified the etiology of VAPA, measured size, and noted the affected vessels.

Results

Forty-five of the 77 patients (58 %) had a delayed diagnosis of VAPA. There was no difference in the rate of missed VAPA in symptomatic compared to asymptomatic patients (p = 0.255). The majority of VAPA were associated with previous surgery or interventions (n = 48/62 %). The major affected vessel was the hepatic (n = 31) followed by the splenic artery (n = 17). The main reasons for misdiagnosis were a missed arterial phase in CT (n = 16/36 %), artifacts masking the aneurysm (n = 9/20 %), overlooked pseudoaneurysm (n = 19/42 %), and misinterpretation by attending radiologists (n = 1/2 %). Missed VAPA were smaller (median 8 mm) than those VAPA that were initially diagnosed (median 13 mm, p < 0.01), but occurred with a similar frequency in larger and smaller visceral arteries (p = 0.601).

Conclusions

Our study showed that 58 % of VAPA were diagnosed with delay, with the following four reasons for misdiagnosis: Lack of an arterial contrast phase in CT, no techniques for artifact reduction, and lack of awareness of the radiologists. Avoiding delayed diagnosis will most probably improve outcome of patients with VAPA.

Successful Localization of the Source of Hemorrhage in Patient with Post-Whipple Surgery by 99mTc-Labelled Red Blood Cell Scintigraphy

Gastrointestinal Bleeding Scintigraphy (GIBS) of ^99mTc-labelled red blood cells is a relatively simple examination to perform, with high diagnostic accuracy and a relatively lower radiation dose. A positive scan can either suggest surgery without further investigation or can indicate angiography, a more targeted procedure. Whipple pancreatoduodenectomy is most often performed for tumors of the head of the pancreas. Pancreatoduodenectomy has 30%–40% morbidity and mortality, and while post-pancreatoduodenectomy hemorrhage is seen in less than 10% of patients, it accounts for 11%–38% mortality. The role of imaging in patients to detect relative hemodynamic stability is essential. Computed tomography angiography (CTA) shows the cause, site, and nature of bleeding, while digital subtraction angiography (DSA) has a diagnostic as well as a therapeutic role. We present a patient who presented with active gastrointestinal bleeding (GI) bleeding after undergoing a Whipple procedure, to highlight the role of GIBS in the successful localization of a bleeding site and the guidance of digital DSA in the embolization and control of the active bleeding.

Significance and Prevalence of Haziness Surrounding the Hepatic Artery and Celiac Axis on Computed Tomographic Imaging After Pancreaticoduodenectomy

PURPOSE

This study was conducted to assess the prevalence and significance of "haziness" around the hepatic artery and celiac axis in patients after pancreaticoduodenectomy.

METHODS

This retrospective study was conducted on 116 patients who underwent pancreaticoduodenectomy or a similar procedure and had no clinical evidence of tumor recurrence or malignancy within 2 years from the date of surgery.

RESULTS

Most images exhibited at least mild to moderate haziness around the hepatic artery and celiac axis. Patients with benign vs malignant results on formal pathology had no significant difference in severity of findings. Haziness remained in the mild to moderate range 2 years after surgery.

CONCLUSIONS

Mild to moderate soft tissue stranding with increased attenuation around the hepatic artery and celiac axis is a common finding after pancreaticoduodenectomy that may persist for years after surgery. Such haziness alone has low specificity for tumor recurrence and should not be regarded as an indicator of malignancy.

Prediction of Late Postoperative Hemorrhage after Whipple Procedure Using Computed Tomography Performed During Early Postoperative Period

Objective

Postpancreatectomy hemorrhage (PPH) is an uncommon but serious complication of Whipple surgery. To evaluate the radiologic features associated with late PPH at the first postoperative follow up CT, before bleeding.

Materials and Methods

To evaluate the radiological features associated with late PPH at the first follow-up CT, two radiologists retrospectively reviewed the initial postoperative follow-up CT images of 151 patients, who had undergone Whipple surgery. Twenty patients showed PPH due to vascular problem or anastomotic ulcer. The research compared CT and clinical findings of 20 patients with late PPH and 131 patients without late PPH, including presence of suggestive feature of pancreatic fistula (presence of air at fluid along pancreaticojejunostomy [PJ]), abscess (fluid collection with an enhancing rim or gas), fluid along hepaticojejunostomy or PJ, the density of ascites, and the size of visible gastroduodenal artery (GDA) stump.

Results

CT findings including pancreatic fistula, abscess, and large GDA stump were associated with PPH on univariate analysis (p ≤ 0.009). On multivariate analysis, radiological features suggestive of a pancreatic fistula, abscess, and a GDA stump > 4.45 mm were associated with PPH (p ≤ 0.031).

Conclusion

Early postoperative CT findings including GDA stump size larger than 4.45 mm, fluid collection with an enhancing rim or gas, and air at fluid along PJ, could predict late PPH.

Diagnostic evaluation of simulation CT images for adjuvant radiotherapy in pancreatic adenocarcinoma

OBJECTIVE

The purpose of this study is to review simulation CT scans and evaluate their diagnostic value in patients treated with adjuvant radiotherapy for pancreatic adenocarcinoma.

METHODS

73 patients who had undergone simulation CT scans for adjuvant radiotherapy in pancreatic adenocarcinoma were reviewed. All simulation CT scans were reviewed by professional abdominal radiologists, who compared the images with corresponding prior CT scans to identify new lesions. Newly detected cancer-related lesions were classified into one of three categories: distant metastasis, locoregional recurrence and indeterminate lesions. Indeterminate lesions were reviewed for malignancy during follow-up imaging work-ups.

RESULTS

Of 73 patients, distant metastasis, locoregional recurrence and indeterminate lesions were found in 4 (5.5%), 5 (6.8%) and 32 patients (43.8%), respectively. Among 32 indeterminate lesions, 24 (75.0%) were soft tissue lesions neighbouring the superior mesenteric vessels. Follow-up PET-CT and diagnostic CT scans revealed that 43.7% of indeterminate lesions were malignant presenting local failures. The 3-year overall survival was significantly higher among patients who had no cancer-related lesions than among who did have such findings (44.8% vs 10.8%, p = 0.002).

CONCLUSION

Professional review of simulation CT scans have ample diagnostic value as they help detect early progressions or potential failures in patients treated with adjuvant radiotherapy for pancreatic adenocarcinoma. Simulation CT scans should be carefully reviewed before the delivery of adjuvant radiotherapy. Advances in knowledge: Generally, simulation CT scan has been known to provide limited diagnostic values and clinical impact. However, the results of this study showed a high detection rate of cancer-related lesions, which could potentially affect subsequent treatment strategies in patients with pancreatic adenocarcinoma.

Normal Postoperative Computed Tomography Findings after a Variety of Pancreatic Surgeries

Pancreatic surgery remains the only curative treatment for pancreatic neoplasms, and plays an important role in the management of medically intractable diseases. Since the original Whipple operation in the 20th century, surgical techniques have advanced, resulting in decreased postoperative complications and better clinical outcomes. Normal postoperative imaging findings vary greatly depending on the surgical technique used. Radiologists are required to be familiar with the normal postoperative imaging findings, in order to distinguish from postoperative complications or tumor recurrence. In this study, we briefly review a variety of surgical techniques for the pancreas, and present the normal postoperative computed tomography findings.

Is routine imaging necessary after pancreatic resection? An appraisal of postoperative ultrasonography for the detection of pancreatic fistula

OBJECTIVES

This study aimed to assess whether routine transabdominal ultrasonography (US) is clinically helpful for the early detection of postoperative pancreatic fistula (PF).

METHODS

In a prospective cohort of patients undergoing partial pancreatectomy, US was performed on postoperative day (POD) 3. Potential predictors of PF, including amylase value in drains (AVD) on POD 1, were investigated. A tree-based classification model of the independent predictors of PF was also performed.

RESULTS

One hundred seventy-three patients were analyzed. A peripancreatic collection on US and an AVD 5000 U/L or greater on POD 1 were predictors of PF. In the tree-based classification model, patients were stratified by AVD on POD 1. For values less than 5000 U/L (incidence of PF, 11.3%), US had a sensitivity of 23.1% and a specificity of 97.5%. For AVD 5000 U/L or greater (incidence of PF, 70.7%), sensitivity was 46.3% and specificity was 100%.

CONCLUSIONS

Despite the presence of a peripancreatic collection as a predictor of PF, US-as a diagnostic test-resulted to be highly specific but poorly sensitive even in the tree-based classification model. Therefore, its role does not seem to be clinically relevant and does not add value to AVD on POD 1, which remains the most powerful and relevant early predictor of PF.

Multidetector CT evaluation of the postoperative pancreas

Several pancreatic diseases may require surgical treatment, with most of these procedures classified as resection or drainage. Resection procedures, which are usually performed to remove pancreatic tumors, include pancreatoduodenectomy, central pancreatectomy, distal pancreatectomy, and total pancreatectomy. Drainage procedures are usually performed to treat chronic pancreatitis after the failure of medical therapy and include the Puestow and Frey procedures. The type of surgery depends not only on the patient's symptoms and the location of the disease, but also on the expertise of the surgeon. Radiologists should become familiar with these surgical procedures to better understand postoperative changes in anatomic findings. Multidetector computed tomography is the modality of choice for identifying normal findings after surgery, postoperative complications, and tumor recurrence in patients who have undergone pancreatic surgery.

Asymptomatic Liver Abscesses Mimicking Metastases in Patients after Whipple Surgery: Infectious Complications following Percutaneous Biopsy-A Report of Two Cases

We present two cases of hepatic abscesses that mimicked metastases in patients having undergone Whipple surgery. Both patients had similar imaging features on computed tomographic (CT) scan and ultrasound, and at the time of referral for biopsy neither patient was clinically suspected to have liver abscess. Both patients underwent biopsy of liver lesions and developed postprocedural infectious complications.

A primer to common major gastrointestinal post-surgical anatomy on CT-a pictorial review

The post-operative abdomen can be challenging and knowledge of normal post-operative anatomy is important for diagnosing complications. The aim of this pictorial essay is to describe a few selected common, major gastrointestinal surgeries, their clinical indications and depict their normal post-operative computed tomography (CT) appearance. This essay provides some clues to identify the surgeries, which can be helpful especially when surgical history is lacking: recognition of the organ(s) involved, determination of what was resected and familiarity with the type of anastomoses used.

CT diagnosis of recurrence after pancreatic cancer: Is there a pattern?

AIM: To investigate predilection sites of recurrence of pancreatic cancer by computed tomography (CT) in follow-up after surgery.

METHODS: Seventy seven patients with recurrence after pancreatic cancer surgery were retrospectively identified. The operative technique, R-status, T-stage and development of tumor markers were evaluated. Two radiologists analyzed CT scans with consensus readings. Location of local recurrence, lymph node recurrence and organ metastases were noted. Surgery and progression of findings on follow-up CT were considered as reference standard.

RESULTS: The mean follow-up interval was 3.9 ± 1.8 mo, with a mean relapse-free interval of 12.9 ± 10.4 mo. The predominant site of recurrence was local (65%), followed by lymph node (17%), liver metastasis (11%) and peritoneal carcinosis (7%). Local recurrence emerged at the superior mesenteric artery (n = 28), the hepatic artery (n = 8), in an area defined by the surrounding vessels: celiac trunk, portal vein, inferior vena cava (n = 22), and in a space limited by the mesenteric artery, portal vein and inferior vena cava (n = 17). Lymph node recurrence occurred in the mesenteric root and left lateral to the aorta. Recurrence was confirmed by surgery (n = 22) and follow-up CT (n = 55). Tumor markers [carbohydrate antigen 19-9 (CA19-9), carcinoembryonic antigen (CEA)] increased in accordance with signs of recurrence in most cases (86% CA19-9; 79.2% CEA).

CONCLUSION: Specific changes of local and lymph node recurrence can be found in the course of the cardinal peripancreatic vessels. The superior mesenteric artery is the leading structure for recurrence.

Hemorrhagic complications after Whipple surgery: imaging and radiologic intervention

OBJECTIVE

The aim of this pictorial essay is to illustrate the radiologic patterns, sites of bleeding, and vascular interventional techniques used in the management of postpancreatectomy hemorrhage.

CONCLUSION

Hemorrhagic complications occur in fewer than 10% of patients after Whipple pancreatoduodenectomy but account for as many as 38% of deaths. Bleeding typically occurs from the stump of the gastroduodenal artery, but other sites of bleeding are increasingly recognized.

Significance of perivascular soft tissue around the common hepatic and proximal superior mesenteric arteries arising after pancreaticoduodenectomy: evaluation with serial MDCT studies

PURPOSE

To evaluate the interval change of perivascular soft tissue (PVST) around the common hepatic and proximal superior mesenteric arteries arising after pancreaticoduodenectomy (PD) and to compare the difference between post operative change (benign PVST) and recurrence (malignant PVST).

MATERIALS AND METHODS

Serial multidetector CT (MDCT) studies in 44 patients who underwent PD for periampullary carcinomas were retrospectively reviewed (Group A). The incidence and interval change of PVST were evaluated and compared to control group (Group B, 21 patients with PD for benign diseases).

RESULTS

PVST was seen in all the 44 patients in Group A, and it was noted in 12 of 21 (57.1%) patients in Group B. Thirteen of 44 (29.5%) patients showed interval enlargement of PVST (malignant PVST), and 12 of 13 developed within 2 years after PD. There was higher incidence of malignant PVST in patients with lymph node metastasis (p < 0.01) and those with pancreas head carcinoma (p < 0.05).

CONCLUSION

PVST is common after PD regardless of whether patients had malignant or benign diseases. PVST should be monitored for at least 2 years to distinguish recurrence from post operative change. Patients with lymph node metastasis and pancreas head carcinoma had a higher incidence of malignant PVST.

Computed tomography after radical pancreaticoduodenectomy (Whipple's procedure)

Whipple's procedure (radical pancreaticoduodenectomy) is currently the only curative option for patients with periampullary malignancy. The surgery is highly complex and involves multiple anastomoses. Complications are common and can lead to significant postoperative morbidity. Early detection and treatment of complications is vital, and high-quality multidetector computed tomography (MDCT) is currently the best method of investigation. This review outlines the surgical technique and illustrates the range of normal postoperative appearances together with the common complications.

CT Features of Pancreatic Fistula After Pancreaticoduodenectomy

OBJECTIVE

Our objective was to establish the CT features that are indicative of pancreatic fistula after pancreaticoduodenectomy.

CONCLUSION

A fluid collection seen on CT around the pancreaticojejunostomy site and in the pancreatic bed may be caused by pancreatic fistula in patients who have undergone pancreaticoduodenectomy. CT depiction of air bubbles in the fluid at these sites may strongly suggest the diagnosis of pancreatic fistula.

Significance of mesenteric lymphadenopathy after pancreaticoduodenectomy for periampullary carcinomas: evaluation with serial MDCT studies

OBJECTIVE

To evaluate the significance of mesenteric lymphadenopathy arising after pancreaticoduodenectomy (PD) for periampullary carcinomas.

MATERIALS AND METHODS

Serial multidetector CT (MDCT) studies in 44 patients after PD for periampullary carcinomas (Group A) were retrospectively reviewed, the incidence and interval changes of mesenteric lymphadenopathy were evaluated, and comparisons were made with 21 patients who underwent PD for benign diseases (Group B).

RESULTS

In Group A, mesenteric lymphadenopathy was seen in 31 of 44 (70.5%) patients. The short axis diameter of the largest lymph node ranged from 6.2 to 11.5mm (mean+/-S.D.: 8.6+/-1.4mm), and the short-axis-to-long-axis (S/L) ratio ranged from 0.46 to 0.99 (mean+/-S.D.: 0.69+/-0.12). Six of the 31 (19.4%) mesenteric lymphadenopathy cases showed interval increases in size on follow-up studies, and three cases showed new development of mesenteric lymphadenopathy: all of these nine cases had concurrent recurrence in the mesenteric root. In Group B, 11 (52.4%) had mesenteric lymphadenopathy. The short axis diameter of the largest lymph node ranged from 5.6 to 10.9mm (mean+/-S.D.: 8.0+/-1.9mm) and the S/L ratio ranged from 0.48 to 0.93 (mean+/-S.D.: 0.67+/-0.12). Differences in the incidence, short axis diameter and S/L ratio were not significant between Groups A and B (p=0.154, 0.271 and 0.654, respectively).

CONCLUSION

Mesenetric lymphadenopathy after PD less likely reflects recurrence. Lymph node metastasis may be suggested only when coexisting recurrent mass is found in the proximal mesenteric root.

Detection of postoperative pancreatitis after pancreatic surgery by urine trypsinogen strip test

Background

The urine trypsinogen strip test has been used successfully in the diagnosis of pancreatitis of various aetiologies, but has not been studied in postoperative pancreatitis. The aim of this study was to evaluate this test for the diagnosis of postoperative pancreatitis after pancreatic resection.

Methods

Fifty patients undergoing pancreatic resection were included. The urine trypsinogen strip test was done daily during the first postoperative week, blood was analysed before and 4, 6 and 10 days after surgery, and amylase activity in the drainage fluid was measured on days 4 and 6. Patients underwent computed tomography (CT) before operation and on days 2 and 6 afterwards.

Results

Thirteen patients (26 per cent) developed CT-detected pancreatitis after operation. In 12 of these patients pancreatitis was detected on the second postoperative day. The urine trypsinogen test was positive in all 13 patients with postoperative pancreatitis, and was already positive on the first day after surgery in 12. The sensitivity, specificity, and positive and negative predictive values of the trypsinogen strip test in detection of postoperative pancreatitis were 100, 92, 81 and 100 per cent respectively. In receiver–operator characteristic analysis the area under the curve (AUC) was higher for the urine trypsinogen strip test (AUC 0·959) than for a serum amylase level more than two (AUC 0·731) or three times (AUC 0·654) above the upper normal range in the diagnosis of postoperative pancreatitis. Patients whose recovery was complicated by pancreatic fistula, detected by drain output measurements on day 6, more often had a positive urine trypsinogen test than patients without a fistula (11 of 12 versus five of 38; P &lt; 0·001).

Conclusion

This study suggests that the urine trypsinogen strip test might be a valuable method for diagnosis of pancreatitis after pancreatic surgery.

Postoperative acute pancreatitis as a major determinant of postoperative delayed gastric emptying after pancreaticoduodenectomy

The aim of this study was to prospectively analyze the possible association of delayed gastric emptying and postoperative pancreatic complications after pancreaticoduodenectomy. Although hospital mortality after pancreaticoduodenectomy is minimal, morbidity is still high; delayed gastric emptying is one of the most frequent complications. Thirty-nine consecutive patients undergoing pancreaticoduodenectomy were included in this study: 14 females and 25 males (median age 65 years; range, 7-82). Delayed gastric emptying was defined as the need for a nasogastric tube or recurrent vomiting that prevented normal feeding on the 10th postoperative day. Blood analysis was performed on postoperative days 4, 6, and 10; Gastrografin examination on day 6; CT scan on days 2 and 5; and drain amylases were measured on day 5. Pancreatitis was defined as pancreatitis changes in CT scan interpreted by an experienced radiologist without knowing other data. Pancreatic fistula was defined according to the recent international recommendations. We had no mortality. Twelve patients (31%) developed delayed gastric emptying. Surgical (9/12 vs. 5/27; P = 0.001) but not medical complications occurred more often in the delayed gastric emptying group. Of the single complications, postoperative CT-detected pancreatitis (6/12 vs. 4/27; P = 0.03) and postoperative pancreatic fistula (5/12 vs. 1/27; P = 0.0007) were significantly associated with delayed gastric emptying compared with the patients without delayed gastric emptying. This pancreatitis was already detected in CT scan on day 2 in most patients (6/10, 60%). In delayed gastric emptying patients, the only parameters in blood analysis that differed significantly from patients without this complication were serum amylase activity (mean +/- SEM, 715 +/- 205 vs. 152 +/- 70 IU/L; P = 0.02), blood leukocyte count (16 +/- 2 vs. 9 +/- 0.6 x 10(9)/L; P = 0.007) and serum C-reactive protein (CRP) concentration (144 +/- 28 vs. 51 +/- 14 mg/L, P = 0.01). Postoperative pancreatic (subclinical) fistula was also associated with postoperative pancreatitis (6/10 vs. 0/29; P = 0.003). Preoperative coronary artery disease (OR = 16; 95% CI, 1.0-241; P = 0.05) and soft pancreatic texture at operation (OR = 9; 95% CI, 1.4-52; P = 0.02) were significant risk factors for the development of postoperative pancreatitis. The diagnosis of delayed gastric emptying after pancreaticoduodenectomy often follows postoperative pancreatitis. Delayed gastric emptying is also associated with postoperative pancreatic fistula, for which this pancreatitis seems to be a risk factor. Preoperative coronary artery disease and soft texture of the pancreas are significant risk factors for postoperative CT-detected pancreatitis.

Extrahepatic portal vein occlusion without recurrence after pancreaticoduodenectomy and intraoperative radiation therapy

PURPOSE

Although there are no definitive studies that characterize the survival benefit of intraoperative radiation therapy (IORT), the therapy does not seem to produce significant complication. In our institution, pancreaticoduodenectomy (PD) and IORT are often complicated by the development of extrahepatic portal vein occlusion (EHPO). The aim of this study was to characterize the phenomenon of EHPO after PD and IORT.

METHODS AND MATERIALS

Between September 1992 and December 2001, 107 patients received macroscopic curative PD for periampullary disease in our institution. IORT (radiation dose: 20 Gy) was performed in 53 of these patients. Criteria for diagnosis of EHPO were as follows: (1) computerized tomography findings of occlusive extrahepatic portal vein, (2) symptoms of portal hypertension, and (3) confirmation to exclude tumor recurrence from origin of EHPO, because this study examined whether EHPO was a complication of PD and IORT.

RESULTS

EHPO was diagnosed in 12 patients. Among patient and operative variables, IORT was the only statistically significant factor associated with a diagnosis of EHPO (p = 0.0052). The median developed time to EHPO and overall survival after surgery in EHPO patients were 358 days and 2,562 days, respectively. Eight patients (67%) with EHPO died during the follow-up period. At 5 years after therapy, EHPO was diagnosed in 67% of survivors who had received IORT.

CONCLUSIONS

Patients undergoing IORT and PD have a relatively high incidence of EHPO, and patients who develop postoperative EHPO have poor prognoses.

[Imaging of pancreatic adenocarcinoma]

Pancreatic cancer remains the fourth most common cause of cancer death. Surgery remains the only option for cure. Accurate diagnosis and staging are essential for appropriate management of patients with pancreatic cancer. This paper reviews the state of the art for imaging modalities in the diagnosis and staging of pancreatic adenocarcinoma. The crucial role of CT has increased with the new generation of multidetector CT.

Imaging evaluation of post pancreatic surgery

The role of several imaging techniques in patients submitted to pancreatic surgery with special emphasis to single-slice helical computed tomography (CT) and multidetector-row CT (MDCT) was reviewed. Several surgical options may be performed such as Whipple procedure, distal pancreatectomy, central pancreatectomy, and total pancreatectomy. Ultrasound examination may be used to detect peritoneal fluid in the early post-operative period as well as lesion recurrence in long-term follow-up. Radiological gastrointestinal studies has a major role in evaluation of intestinal functionality. In spite of the advent of other imaging modalities, CT is the most effective after pancreatic surgery. On post-operative CT, the most common findings were small fluid peritoneal or pancreatic collections, stranding of the mesenteric fat with perivascular cuffing, reactive adenopathy and pneumobilia. In addition, CT may demonstrate early (leakage of anastomosis, pancreatico-jejunal fistula, haemorrage, acute pancreatitis of the remnant pancreas, peritonitis), and late (chronic fistula, abscess, aneurysms, anastomotic bilio-digestive stenosis, perianastomotic ulcers, biloma, and intra-abdominal bleeding) surgical complications. In the follow-up evaluation, CT may show tumor recurrence, liver and lymph nodes metastasis. Magnetic resonance may be used as alternative imaging modality to CT, when renal insufficiency or contrast sensitivity prevents the use of iodinated i.v. contrast material or when the biliary tree study is primarily requested. The knowledge of the type of surgical procedures, the proper identification of the anastomoses as well as the normal post-operative imaging appearances are essential for an accurate detection of the complications and recurrent disease.

Imaging After a Whipple Operation

OBJECTIVE

Spiral computed tomography (CT) examination of patients after a Whipple operation often raises questions concerning the afferent loop. This study evaluates the efficiency of biliary contrast medium (BCM) in visualizing opacification of this loop.

METHODS

After undergoing a Whipple operation, 31 patients received 100 mL BCM before postoperative spiral CT (Somatom Plus 4; Siemens, Erlangen, Germany: 5- or 10-mm slices, feed of 7 or 12 mm/s; Volume Zoom; Siemens: 2.5 mm collimation, total feed of 15 mm/s). Semiquantitative evaluation included opacification of the jejunal loop and visibility of jejunostomies. Complications and tumor recurrences were recorded.

RESULTS

In all patients, BCM was successfully administered without complications. Afferent loop opacification was seen in 95% of examinations with BCM versus 5% of examinations with oral contrast medium. Evaluation of jejunostomies was unequivocally facilitated by BCM. Three previously undetermined changes were identified as tumor recurrence, and recurrence was ruled out after examination with BCM in 7 cases.

CONCLUSIONS

After a Whipple operation, opacification of the afferent loop can be regularly achieved by intravenous administration of BCM, which eases distinction of normal postoperative changes from local tumor recurrence. Administration of BCM is recommended as a standard diagnostic procedure in these patients.

Spiral CT following the Whipple procedure: distinguishing normal postoperative findings from complications

Following a Whipple procedure for a patient with pancreatic cancer, postoperative imaging with CT is essential to exclude complications and to identify recurrence. Accurate interpretation of these examinations requires knowledge of the type of surgery performed and the normal appearance of the abdomen on CT following this complex surgery. The purpose of this pictorial essay is to illustrate the normal appearance of the bowel following a Whipple procedure as well as some of the complications.

Cost-effectiveness analysis of alternative strategies for palliation of distal biliary obstruction after a failed cannulation attempt

OBJECTIVES

Occasionally alternative techniques such as precut sphincterotomy or percutaneous transhepatic cholangiography (PTC) are required to achieve access to the common bile duct. Tradeoffs exist, however, with respect to their complications and costs. Some experts believe that precut sphincterotomy should not be performed at all. We aimed to compare the cost-effectivenesses of metallic biliary stent placement after an initial failed cannulation attempt at ERCP utilizing precut sphincterotomy and placement utilizing PTC for palliation of jaundice. A cost-effectiveness analysis was performed, as viewed from the societal perspective.

METHODS

A decision analysis model was designed comparing precut sphincterotomy and PTC approaches for placement of a metallic biliary stent for palliation of jaundice in a patient with inoperable malignant distal biliary obstruction in whom an initial attempt at ERCP cannulation had failed. Baseline probabilities, obtained from the published literature, were varied through plausible ranges using sensitivity analysis. Charges were based on Medicare professional plus facility fees or diagnosis-related group rates for out- and inpatients, respectively. The outcome measured was cost per year of life.

RESULTS

Sensitivity analysis showed that precut sphincterotomy with subsequent PTC, if necessary, was the most cost-effective strategy provided the precut complication rate was <51% ($9,033/yr), versus $14,741/yr for PTC.

CONCLUSIONS

Precut sphincterotomy followed by PTC (if necessary) is the most cost-effective strategy for palliative biliary stenting in the setting of malignant distal biliary obstruction after a failed ERCP attempt. The endoscopic approach is best practiced by experienced endoscopists who minimize precut complication rates.

Complications after pancreatoduodenectomy: imaging and imaging-guided interventional procedures

Over the past decade, performance of the Whipple procedure, or pancreatoduodenectomy, to treat both malignant and benign disease has increased. This increase is in large part due to the decreasing perioperative mortality rate, which is down from historic highs of 25% to the 1.0%--1.5% now achieved in large centers. Although advances in surgical management have improved the outlook for patients undergoing pancreatoduodenectomy, the improving mortality rate is also in part attributed to improvements over the past 2 decades in cross-sectional imaging and imaging-guided interventional procedures. Although the mortality rates have improved, the morbidity, or rate of complications, has remained relatively constant. Contributions by radiologists in both diagnosis and treatment of complications are crucial in certain patients with postpancreatoduodenectomy abdominal abscesses, bilomas, liver abscess, and biliary obstruction. Familiarity with normal variations in the postoperative appearance of the upper abdomen, awareness of pitfalls in interpretation, and knowledge of the available imaging-guided interventions will facilitate recognition of postpancreatoduodenectomy complications and allow prompt triage of patients to imaging-guided interventions.

Common surgical procedures

This article illustrates some common surgical procedures. Radiologists and other physicians frequently see patients who have had one or more of these operations. We hope to illustrate with drawings and radiographs the basic purpose of the procedures and the relevant anatomy. This is not intended to illustrate or discuss the actual surgical techniques. Our intention is to illustrate one generally accepted way of performing a given type of surgical procedure. For many of these operations, there may be multiple other techniques to accomplish the same result for the patient. Some of the illustrations and text in this monograph were originally published in Radiologic Guide to Medical Devices and Foreign Bodies, edited by T.B. Hunter and D.G. Bragg, St. Louis: Mosby-Year Book, 1994.