Imaging evaluation of post pancreatic surgery

Modified Appleby procedure for locally advanced pancreatic carcinoma: A primer for the radiologist

Pancreatic ductal adenocarcinoma (PDAC) is the most prevalent pancreatic neoplasm accounting for more than 90% of pancreatic malignancies. Surgical resection with adequate lymphadenectomy remains the only available curative strategy for patients with PDAC. Despite improvements in both chemotherapy regimen and surgical care, body/neck PDAC still conveys a poor prognosis because of the vicinity of major vascular structures, including celiac trunk, which favors insidious disease spread at the time of diagnosis. Body/neck PDAC involving the celiac trunk is considered locally advanced PDAC in most guidelines and therefore not eligible for upfront resection. However, a more aggressive surgical approach (i.e., distal pancreatectomy with splenectomy and en-bloc celiac trunk resection [DP-CAR]) was recently proposed to offer hope for cure in selected patients with locally advanced body/neck PDAC responsive to induction therapy at the cost of higher morbidity. The so-called "modified Appleby procedure" is highly demanding and requires optimal preoperative staging as well as appropriate patient preparation for surgery (i.e., preoperative arterial embolization). Herein, we review current evidence regarding DP-CAR indications and outcomes as well as the critical role of diagnostic and interventional radiology in patient preparation before DP-CAR, and early identification and management of DP-CAR complications.

Postoperative single-sequence (PoSSe) MRI: imaging work-up for CT-guided or endoscopic drainage indication of collections after hepatopancreaticobiliary surgery

Purpose

Fluid collections due to anastomotic leakage are a common complication after hepatopancreaticobiliary (HPB) surgery and are usually treated with drainage. We conducted a study to evaluate imaging work-up with a postoperative single-sequence (PoSSe) MRI for the detection of collections and indication of drainage.

Material and methods

Forty-six patients who developed signs of leakage (fever, pain, laboratory findings) after HPB surgery were prospectively enrolled. Each patient was examined by abdominal sonography and our PoSSe MRI protocol (axial T2-weighted HASTE only). PoSSe MRI examination time (from entering to leaving the MR scanner room) was measured. Sonography and MRI were evaluated regarding the detection and localization of fluid collections. Each examination was classified for diagnostic sufficiency and an imaging-based recommendation if CT-guided or endoscopic drainage is reasonable or not was proposed. Imaging work-up was evaluated in terms of feasibility and the possibility of drainage indication.

Results

Sonography, as first-line modality, detected 21 focal fluid collections and allowed to decide about the need for drainage in 41% of patients. The average time in the scanning room for PoSSe MRI was 9:23 min [7:50–13:32 min]. PoSSe MRI detected 46 focal collections and allowed therapeutic decisions in all patients. Drainage was suggested based on PoSSe MRI in 25 patients (54%) and subsequently indicated and performed in 21 patients (100% sensitivity and 84% specificity). No patient needed further imaging to optimize the treatment.

Conclusions

The PoSSe MRI approach is feasible in the early and intermediate postoperative setting after HPB surgery and shows a higher detection rate than sonography. Imaging work-up regarding drainage of collections was successful in all patients and our proposed PoSSe MRI algorithm provides an alternative to the standard work-up.

Computed tomography evaluation of early post-operative complications of the Whipple procedure

Purpose

Pancreaticoduodenectomy (the Whipple procedure) is the only potential curative treatment for periampullary tumours. Although mortality due to the procedure is gradually decreasing, the morbidity rates remain high. This study aimed to evaluate early computed tomography (CT) findings in patients suspected of complications following the Whipple procedure.

Material and methods

The CT images of patients who underwent the conventional Whipple procedure between January 2015 and January 2019 and underwent CT examination for the detection of early postoperative complications were retrospectively evaluated by two radiologists.

Results

The Whipple operation was performed to 65 patients, and the CT scans of 45 patients (30 males, 15 females) were included in the study. There were no complications in 21 patients. Complications were present in 24 patients (53.33%), of whom 13 had more than one complication. Eight patients had fluid collection in the operation site, two had haematoma, 10 had an abscess, and five had a pancreatic fistula. In addition, a hepatic abscess was detected in one patient, delayed gastric emptying in six patients, anastomotic leakage from the gastrojejunostomy line in two patients, superior mesenteric vein (SMV) thrombosis in two patients, and intraluminal haemorrhage and active extravasation in one patient. Mortality due to complications occurred in one patient in the early postoperative period. Other complications were treated by spontaneous, surgical or percutaneous interventional procedures.

Conclusions

Despite the decreasing mortality rates in recent years, the Whipple procedure is risky and has high morbidity even when performed in experienced centres. CT is the adequate imaging modality for the evaluation of this anatomically altered region and detection of complications.

The Clinical Implications of Peripancreatic Fluid Collection After Distal Pancreatectomy

OBJECTIVES

Pancreatic fistula after distal pancreatectomy (DP) remains an unsolved problem, and postoperative CT imaging often demonstrates fluid collection (FC) around the pancreatic remnant. This study sought to clarify the clinical implications of FC.

METHODS

This study enrolled 146 patients who underwent DP. FC was defined as a cyst-like lesion ≥ 10 mm in diameter on CT imaging at postoperative day (POD) 7. FC size, irregularity of FC margin, and air bubbles in FC were investigated. In addition, clinical data were retrospectively collected, and useful predictive factors for postoperative pancreatic fistula (POPF) were analyzed.

RESULTS

Clinically relevant POPF was observed in 26 patients (17.8%), and FC was detected in 136 patients (94.4%). Multivariate analysis identified FC size and drain amylase levels on POD3 as significant risk factors for POPF. Cutoff values were determined by ROC analyses, and the levels of the FC size and drain amylase on POD3 were determined as 41 mm and 1026 IU/L, respectively. The sensitivity and specificity of FC diameters > 41 mm were 76.9% and 75.0%, respectively, while those of drain amylase levels > 1026 IU on POD3 were 73.1% and 75.8%, respectively.

CONCLUSIONS

While treating some FCs after DP was necessary for the management of POPF, others did not require any intervention since most of them spontaneously disappeared. FC size and drain amylase levels on POD3 were found to be significantly associated with POPF and could potentially help to determine appropriate treatment.

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.

Major pancreatic resections: normal postoperative findings and complications

Objectives

(1) To illustrate and describe the main types of pancreatic surgery; (2) to discuss the normal findings after pancreatic surgery; (3) to review the main complications and their radiological findings.

Background

Despite the decreased postoperative mortality, morbidity still remains high resulting in longer hospitalisations and greater costs. Imaging findings following major pancreatic resections can be broadly divided into “normal postoperative alterations” and real complications. The former should regress within a few months whereas complications may be life-threatening and should be promptly identified and treated.

Imaging findings

CT is the most effective postoperative imaging technique. MRI and fluoroscopy are used less often and only in specific cases such as assessing the gastro-intestinal function or the biliary tree. The most common normal postoperative findings are pneumobilia, perivascular cuffing, fluid collections, lymphadenopathy, acute anastomotic oedema and stranding of the peri-pancreatic/mesenteric fat. Imaging depicts the anastomoses and the new postoperative anatomy. It can also demonstrate early and late complications: pancreatic fistula, haemorrhage, delayed gastric emptying, hepatic infarction, acute pancreatitis of the remnant, porto-mesenteric thrombosis, abscess, biliary anastomotic leaks, anastomotic stenosis and local recurrence.

Conclusions

Radiologists should be aware of surgical procedures, postoperative anatomy and normal postoperative imaging findings to better detect complications and recurrent disease.

Teaching Points

• Morbidity after pancreatic resections is high.

• CT is the most effective postoperative imaging technique.

• Imaging depicts the anastomoses and the new postoperative anatomy.

• Pancreatic fistula is the most common complication after partial pancreatic resection.

Imaging of post-operative pancreas and complications after pancreatic adenocarcinoma resection

Pancreatic ductal adenocarcinoma is one of the leading causes of cancer-related deaths. With surgical resection being the only definitive treatment, improvements in technique has led to an increase in number of candidates undergoing resection by inclusion of borderline resectable disease patients to the clearly resectable group. Post-operative complications associated with pancreaticoduodenectomy and distal pancreatectomy include delayed gastric emptying, anastomotic failures, fistula formation, strictures, abscess, infarction, etc. The utility of dual-phase CT with multiplanar reconstruction and 3D rendering is increasingly recognized as a tool for the assessment of complications associated with vascular resection and reconstruction such as hemorrhage, pseudoaneurysm, vascular thrombosis, and ischemia. Prompt recognition of the complications and distinction from benign post-operative findings such as hepatic steatosis and mesenteric fat necrosis on imaging plays a key role in helping decrease the morbidity and mortality associated with surgery. We discuss, with case examples, some of such common and uncommon findings on imaging to familiarize the abdominal radiologists evaluating post-operative imaging in both acute and chronic post-operative settings.

Multi-institutional survey on imaging practice patterns in pancreatic ductal adenocarcinoma

PURPOSE

To study the practice patterns for performance and interpretation of CT/MRI imaging studies in patients with pancreatic ductal adenocarcinoma (PDAC) at multiple institutions using a survey-based assessment.

METHODS

In this study, abdominal radiologists/body imagers on the Society of Abdominal Radiology disease-focused panel for PDAC and from multiple institutions participated in an online survey. The survey was designed to investigate the imaging and reporting practice patterns for PDAC. The survey questionnaire addressed the experience of referring providers, choice of imaging modality for diagnosis and follow-up of PDAC, structured imaging templates utilization for PDAC, and experiences with the use of structured reports.

RESULTS

The response rate was 89.6% (43/48), with majority of the respondents working in a teaching hospital or academic research center (95.4%). While 86% of radiologists reported use of structured reporting templates in their practice, only 60.5% used standardized templates specific to PDAC. This lower percentage was despite most of them (77%) being aware of existence of PDAC-specific templates and recognizing their benefits, such as preference by referring providers (83%), improved uniformity (100%), and higher accuracy of reports (76.2%). The common impediments to the use of PDAC-specific templates were interference with efficient workflow (67.5%), lack of interest (52.5%), and complexity of existing templates (47.5%). With regards to imaging practice, 92.7% (n = 40/43) of respondents reported performing dynamic multiphasic pancreatic protocol CT for evaluation of patients with initial suspicion or staging of PDAC.

CONCLUSION

Structured reporting templates for PDAC are not universally utilized in subspecialty abdominal/body imaging practices due to concerns of interference with efficient workflow and complexity of templates. Multiphasic pancreatic protocol CT is most frequently performed for evaluation of PDAC.

Pancreatic tumors imaging: An update

Currently, ultrasound (US), computed tomography (CT) and Magnetic Resonance imaging (MRI) represent the mainstay in the evaluation of pancreatic solid and cystic tumors affecting pancreas in 80-85% and 10-15% of the cases respectively. Integration of US, CT or MR imaging is essential for an accurate assessment of pancreatic parenchyma, ducts and adjacent soft tissues in order to detect and to stage the tumor, to differentiate solid from cystic lesions and to establish an appropriate treatment. The purpose of this review is to provide an overview of pancreatic tumors and the role of imaging in their diagnosis and management. In order to a prompt and accurate diagnosis and appropriate management of pancreatic lesions, it is crucial for radiologists to know the key findings of the most frequent tumors of the pancreas and the current role of imaging modalities. A multimodality approach is often helpful. If multidetector-row CT (MDCT) is the preferred initial imaging modality in patients with clinical suspicion for pancreatic cancer, multiparametric MRI provides essential information for the detection and characterization of a wide variety of pancreatic lesions and can be used as a problem-solving tool at diagnosis and during follow-up.

How the radiologist can add value in the evaluation of the pre- and post-surgical pancreas

Disease involving the pancreas can be a significant diagnostic challenge to the interpreting radiologist. Moreover, the majority of disease processes involving the pancreas carry high significant morbidity and mortality either due to their natural process or related to their treatment options. As such, it is critical for radiologists to not only provide accurate information from imaging to guide patient management, but also deliver that information in a clear manner so as to aid the referring physician. This is no better exemplified than in the case of pre-operative staging for pancreatic adenocarcinoma. Furthermore, with the changing healthcare landscape, it is now more important than ever to ensure that the value of radiology service to other providers is high. In this review, we will discuss how the radiologist can add value to the referring physician by employing novel imaging techniques in the pre-operative evaluation as well as how the information can be conveyed in the most meaningful manner through the use of structured reporting. We will also familiarize the radiologist with the imaging appearance of common complications that occur after pancreatic surgery.

Postoperative reactive lymphadenitis: A potential cause of false-positive FDG PET/CT

A wide variety of surgical related uptake has been reported on F18-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG PET/CT) scan, most of which can be differentiated from neoplastic process based on the pattern of FDG uptake and/or anatomic appearance on the integrated CT in image interpretation. A more potential problem we may be aware is postoperative reactive lymphadenitis, which may mimic regional nodal metastases on FDG PET/CT. This review presents five case examples demonstrating that postoperative reactive lymphadenitis could be a false-positive source for regional nodal metastasis on FDG PET/CT. Surgical oncologists and radiologists should be aware of reactive lymphadenitis in interpreting postoperative restaging FDG PET/CT scan when FDG avid lymphadenopathy is only seen in the lymphatic draining location from surgical site.

Magnetic resonance imaging of the postoperative pancreas

Magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography provides the comprehensive evaluation of patients following pancreatic surgery regarding parenchymal pancreatic changes, ductal abnormalities, evaluation of anastomoses, and detection of tumor recurrence. Normal and pathologic MRI presentations in patients who underwent pancreatic surgery are reviewed. The MRI/magnetic resonance cholangiopancreatography techniques used in the patients after pancreatic surgery are presented, and a concise review of the current array of pancreatic surgical procedures is provided.

Contrast enhanced ultrasound (CEUS) in blunt abdominal trauma

In the assessment of polytrauma patient, an accurate diagnostic study protocol with high sensitivity and specificity is necessary. Computed Tomography (CT) is the standard reference in the emergency for evaluating the patients with abdominal trauma. Ultrasonography (US) has a high sensitivity in detecting free fluid in the peritoneum, but it does not show as much sensitivity for traumatic parenchymal lesions. The use of Contrast-Enhanced Ultrasound (CEUS) improves the accuracy of the method in the diagnosis and assessment of the extent of parenchymal lesions. Although the CEUS is not feasible as a method of first level in the diagnosis and management of the polytrauma patient, it can be used in the follow-up of traumatic injuries of abdominal parenchymal organs (liver, spleen and kidneys), especially in young people or children.

Role of secretin-enhanced magnetic resonance cholangiopancreatography in the evaluation of patients following pancreatojejunostomy

Objective:

This study was conducted to assess the role of secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) in the evaluation of patients following pancreatico-jejunal anatomosis.

Materials and Methods:

S-MRCP studies (n = 83) performed at Brigham and Women's Hospital between 1/2005 and 7/2005 were retrospectively reviewed. Among these, there were 13 patients (10 females, 3 males; mean age = 45 years, range = 18-74 years) who were evaluated with S-MRCP following pancreatojejunal anatomosis. Single-shot fast spin-echo T2-weighted thick slab dynamic MRCP images obtained before and every minute (for 10 min) after IV injection of secretin (2 mcg/kg body weight of SecreFloTM IV over 1 min) were reviewed retrospectively and independently by 3 readers. Image analysis included measurement of the main pancreatic duct (MPD) diameter and subjective assessment of the grade of visualization of the MPD remnant. The amount of jejunal fluid and visualization of the pancreatico-jejunal anatomosis pre-and post-secretin were also documented. Direct correlation with endoscopic retrograde cholangiopancreatography (ERCP) finding was available in six of the 13 cases.

Results:

The MPD diameter and MPD remnant visualization improved post-secretin for 1/3 readers. The number of pancreatico-jejunal anastomoses and the amount of jejunal fillings pre-and post-secretin was seen to improve significantly for 1 of the 3 readers. For Reader 1, the mean MPD diameter in the body of the pancreas, on the pre-and post-secretin image, was 3.2 ± 1.3 mm and 3.8 ± 1.9 mm, respectively. There was no statistical difference in the values pre- and post-secretin in the MPD diameter (P = 0.07), MPD visualization (P = 0.16) and the number of pancreatico-jejunal anastomoses seen (P = 0.125 5/13 pre- and 9/13 post-secretin). Statistical significance was seen in the amount of jejunal filling (P = 0.01) after secretin. For Reader 2, the MPD diameter pre-and post-secretin was 4 ± 2 and 3.9 ± 2.1 mm, respectively (P = 0.89). The MPD visualization (P = 0.19) and degree of jejunal filling (P = 0.7) did not improve significantly. There were 3/13 pancreatico-jejunostomy anastomoses seen pre- and 8/13 seen post-secretin (P = 0.06). The values for Reader 3 reached a statistical significance for the measurement of MPD (P = 0.032). In addition, MPD visualization (P = 0.038), the number of anastomoses seen (P = 0.016) and jejunal filling (P = 0.006) were also significantly improved.

Conclusion:

The addition of intravenous secretin to an MRCP study in the evaluation of patients following pancreatojejunal anastomosis does not significantly impact the visualization of the pancreatic duct. However, secretin may improve the assessment of the pancreatico-jejunal anastomosis.

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.

Reactive hypertrophy of an accessory spleen mimicking tumour recurrence of metastatic renal cell carcinoma

De novo occurrence of an accessory spleen after splenectomy is worth noting for two reasons. First, it is known that splenectomy can cause reactive hypertrophy of initially inactive and macroscopically invisible splenic tissue. Second, it can mimic tumour recurrence in situations in which splenectomy has been performed for oncological reasons. This might cause difficulties in differential diagnosis and the clinical decision for reoperation. We report the case of a patient with suspected recurrence of renal cell carcinoma after total pancreatectomy and splenectomy for metastatic renal cell carcinoma, which finally revealed an accessory spleen as the morphological correlate of the newly diagnosed mass in the left retroperitoneum.

The importance of radiological controls of anastomoses after upper gastrointestinal tract surgery - a retrospective cohort study

INTRODUCTION

This study was designed to analyze whether routine radiological controls of anastomoses in the upper gastrointestinal tract an early detection of anastomotic leaks.

PATIENTS AND METHODS

135 patients who underwent upper gastrointestinal tract surgery were retrospectively analyzed. Patients in the first group (n = 55) underwent routine radiological control of the anastomoses. In the second group (n = 80) the radiological control was only performed in case of clinical symptoms or signs of anastomotic leaks.

RESULTS

The incidence of anastomotic leaks in the patients seen by us was 5.2%, equivalent to 7 of 135 patients In Group 1 leaks were seen in 4 of 55 patients (7,2%) in group 2 leaks were seen in 3 of 80 (3,8%). The radiological control of the anastomoses with contrast swallow showed the leakage in two cases. Twice the results were false negative. The sensitivity of computed tomography was 100%.

DISCUSSION

Routine radiological control of anastomoses with contrast swallow only has low sensitivity. This procedure should not be performed routinely any more.The radiological control should be used in cases with signs of anastomotic leakage or with postoperatively impaired gastrointestinal passage.

Acute necrotizing pancreatitis complicated with pancreatic pseudoaneurysm of the superior mesenteric artery: A case report

Acute necrotizing pancreatitis complicated with pancreatic pseudoaneurysm is a rare emergency associated with high mortality that demands immediate treatment to save the patient’s life. We treated a 64-year-old man who presented with a bleeding pseudoaneurysm of the superior mesenteric artery caused by acute pancreatitis, using interventional embolizing therapy. In the present report we show that interventional treatment is an effective therapeutic modality for patients with acute necrotizing pancreatitis complicated with intra-abdominal bleeding.