Ultrasonography of the pancreas. 7. Intraoperative imaging

Intraoperative Ultrasound During Surgical Exploration in Patients with Pancreatic Cancer and Vascular Involvement (ULTRAPANC): A Prospective Multicenter Study

BACKGROUND

Determining the resectability of pancreatic cancer with vascular involvement on preoperative computed tomography imaging remains challenging, especially following preoperative chemotherapy and chemoradiotherapy. Intraoperative ultrasound (IOUS) may provide real-time additional information, but prospective multicenter series confirming its value are lacking.

PATIENTS AND METHODS

This prospective multicenter study included patients undergoing surgical exploration for pancreatic cancer with vascular involvement. All patients underwent IOUS at the start of explorative laparotomy. Primary outcomes were resectability status as defined by the National Comprehensive Cancer Network and the extent of vascular involvement.

RESULTS

Overall, 85 patients were included, of whom 74 (87%) were post preoperative chemotherapy, and mostly following FOLFIRINOX regimen (n = 57; 76%). On the basis of preoperative imaging, 34 (40%) patients were staged as resectable (RPC), 32 (38%) borderline resectable (BRPC), and 19 (22%) locally advanced pancreatic cancer (LAPC). IOUS changed the resectability status in 32/85 (38%) patients (p < 0.001), including 8/19 (42%) patients with LAPC who were downstaged (4 to BRPC, 4 to RPC), and 22/32 (69%) patients with BRPC who were downstaged to RPC. Among patients with presumed superior mesenteric artery (SMA) involvement, 20/28 (71%) had no SMA involvement on IOUS. In 15 of these 20 patients a pancreatic resection was performed, all with R0 SMA margin.

CONCLUSION

IOUS during surgical exploration for pancreatic cancer and vascular involvement downstaged the resectability status in over one-third of patients, which could facilitate progress during surgical exploration. This finding should be confirmed by larger studies, including detailed pathology assessment. Trial Registration www.trialregister.nl (NL7621).

Intraoperative Characterization of Pancreatic Tumors Using Contrast-Enhanced Ultrasound and Shear Wave Elastography for Optimization of Surgical Strategies

OBJECTIVES

To evaluate intraoperative contrast-enhanced ultrasound (IoCEUS) and intraoperative shear wave elastography (IoSWE) for characterization of focal pancreatic lesions (FPLs) in correlation with postoperative histologic results. Thereby, the impact of intraoperative ultrasound (US) on pancreas surgery was evaluated.

METHODS

Intraoperative CEUS and SWE data from 54 patients, who underwent pancreas surgery between 2017 and 2019, were analyzed retrospectively. Ultrasound examinations were performed with multifrequency linear/T-shaped transducers (3-9 MHz) on a high-end US device (LOGIQ E9; GE Healthcare, Chicago, IL). To analyze FPL stiffness by SWE, regions of interest were placed to measure the shear wave speed (meters per second) and stiffness (kilopascals). After intravenous bolus injections of 2.4 to 10 mL of sulfur hexafluoride microbubbles, a dynamic analysis of FPL microvascularization from arterial to late phases was performed using IoCEUS considering hypoenhancement/irregular vascularization of macrocystic/small solid FPL malignancy criteria. Ultrasound findings were correlated with postoperative histologic results. The impact of intraoperative US on surgery was documented in each case.

RESULTS

Of 54 FPLs, IoCEUS could correctly characterize 39 of 39 malignant and 6 of 15 benign FPLs; IoSWE 29 of 39 as malignant and 7 of 15 as benign. Intraoperative CEUS's sensitivity was 100%; specificity, 40%; accuracy, 83.3%; positive predictive value, 81.3%; and negative predictive value, 100% (P < .05). Applying cutoff values of 3 m/s and 28.7 kPa, SWE's sensitivity was 74.4%; specificity, 46.7%; accuracy, 66.7%; positive predictive value; 78.4%; and negative predictive value, 41.2% for cancer detection (P < .05). The combined use of both techniques showed an accuracy rate of 76%, sensitivity of 74.4%, and specificity of 33.3%. In 29.6%, US results had an immediate impact on surgery.

CONCLUSIONS

Intraoperative SWE and CEUS are highly valuable techniques for intraoperative characterization of FPLs. Although IoCEUS proved to be superior to IoSWE, the combined use can be helpful in particular cases.

Multimodality Approach in Detection and Characterization of Hepatic Metastases

Early detection of liver metastases is important in patients with known primary malignancies. This plays an important role in treatment planning and impacts on further management of certain primary malignancies.

Magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography-computed tomography scans are reported to have high accuracy in the diagnosis of intrahepatic lesions. MRI in particular has the advantages of its high tissue sensitivity and its multiparametric approach.

Hepatic metastatic lesions have considerable overlap in their radiological appearance, and in this article the imaging appearance of various hepatic metastasis and approach is described.

A Prospective Clinical Trial to Determine the Effect of Intraoperative Ultrasound on Surgical Strategy and Resection Outcome in Patients with Pancreatic Cancer

Surgical exploration in patients with pancreatic or periampullary cancer is often performed without intraoperative image guidance. Although intraoperative ultrasound (IOUS) may enhance visualization during resection, this tool has not been investigated in detail until now. Here, we performed a prospective cohort study to evaluate the effect of IOUS on surgical strategy and to evaluate whether vascular involvement and radicality of the resection could be correctly assessed with IOUS. IOUS was performed by an experienced abdominal radiologist during surgical exploration in 31 consecutive procedures. IOUS affected surgical strategy by either (i) having no effect, (ii) determining tumor localization, (iii) evaluating vascular involvement or (iv) waiving surgery. Radicality of the resections and vascular contact were determined during pathologic analysis and compared with preoperative imaging and IOUS findings. Overall, IOUS influenced surgical strategy in 61% of procedures. In 21 out of 27 malignant tumors, a radical resection was achieved (78%). Vascular contact was assessed correctly using IOUS in 89% compared with 74% of patients using preoperative imaging. IOUS can help the surgical team to assess the resectability and to visualize the tumor and possible vascular contact in real time during resection. IOUS may therefore increase the likelihood of achieving a radical resection.

Value of Intraoperative Sonography in Pancreatic Surgery

The utility of intraoperative sonography for pancreatic disease has been well described for detection and evaluation of neoplastic and inflammatory pancreatic disease. Intraoperative sonography can help substantially reduce surgical time as well as decrease potential injury to tissues and major structures. Imaging with sonography literally at the point of care--the surgeon's scalpel--can precisely define the location of pancreatic lesions and their direct relationship with surrounding structures in real time during surgery. This article highlights our experience with intraoperative sonography at multiple institutional sites for both open and laparoscopic surgical procedures. We use intraoperative sonography for a wide range of pancreatic disease to provide accurate localization and staging of disease, provide guidance for enucleation of nonpalpable, nonvisible tumors, and in planning the most direct and least invasive surgical approach, avoiding injury to the pancreatic duct or other vital structures.

The use of intraoperative ultrasound for diagnosis and stadiation in pancreatic head neoformations

The intraoperative staging of the pancreatic cancer is important to make a proper treatment. For this reason the intraoperative echography is playing an important role in the right treatment choice. The intraoperative echography, that can be performed with an open or laparoscopic probe, is used to confirm the preoperative diagnosis and assess the pancreatic cancer resecability. The intraoperative echography (IOUS) or laparoscopic intraoperative echography (LIOUS) are useful to identify the patients with a non resecable cancer and perform a faster neoadjuvant treatment. The LIOUS can also avoid an useless laparotomy. The aim of this study is to assess, both in our experience and in the cited literature, the concordance rate between the pancreatic cancer preoperative staging, performed with TC and MRI (when it is available), and intraoperative staging, performed with intraoperative laparotomic or laparoscopic echography.

MATERIAL AND METHODS

We have analyzed the treatment management of 34 patients, who were candidate to major surgery for suspected pancreatic head cancer and who underwent to intraoperative LIOUS or IOUS staging from 2001 to 2012.

RESULTS

LIOUS and IOUS have allowed to detect cases in which preoperative diagnosis, proved by CT and MRI, was not agreeing with intraoperative diagnosis (22 patients on 34, 64% discordance rate), avoiding the execution of a demolitive and uneseful surgery in order to guarantee the surveillance and life's quality of patients.

CONCLUSION

We suggest to perform in every patients undergone to pancreatic surgery an intraoperative ultrasound exam, to detect unresecable and unpredicted lesions.

The role of intraoperative ultrasonography in the diagnosis and management of focal hepatic lesions

Intraoperative ultrasonography (IOUS) has been widely utilized in hepatic surgery both as a diagnostic technique and in the course of treatment. Since IOUS involves direct-contact imaging of the target organ, it can provide high spatial resolution without interference from the surrounding structures. Therefore, IOUS may improve the detection, characterization, localization, and local staging of hepatic tumors. IOUS is also a real-time imaging modality capable of providing interactive information and valuable guidance in a range of procedures. Recently, contrast-enhanced IOUS, IOUS elastography, and IOUS-guided hepatic surgery have attracted increasing interest and are expected to lead to the broader implementation of IOUS. Herein, we review the various applications of IOUS in the diagnosis and management of focal hepatic lesions.

Applications of intraoperative ultrasound in the treatment of complicated cases of acute and chronic pancreatitis and pancreatic cancer - own experience

Both acute and chronic inflammation of the pancreas often lead to complications that nowadays can be resolved using endoscopic and surgical procedures. In many cases, intraoperative ultrasound examination (IOUS) enables correct assessment of the extent of the lesion, and allows for safe surgery, while also shortening its length.

AIM OF THE RESEARCH

At the authors' clinic, intraoperative ultrasound is performed in daily practice. In this paper, we try to share our experiences in the application of this particular imaging technique.

RESEARCH SAMPLE AND METHODOLOGY

Intraoperative examination conducted by a surgeon who has assessed the patient prior to surgery, which enabled the surgeon to verify the initial diagnosis. The material presented in this paper includes 145 IOUS procedures performed during laparotomy due to lesions of the pancreas, 57 of which were carried out in cases of inflammatory process.

RESULTS AND CONCLUSIONS

IOUS is a reliable examination tool in the evaluation of acute inflammatory lesions in the pancreas, especially during the surgery of chronic, symptomatic inflammation of the organ. The procedure allows for a correct determination of the necessary scope of the planned surgery. The examination allows for the differentiation between cystic lesions and tumors of cystic nature, dictates the correct strategy for draining, as well as validates the indications for the lesion's surgical removal. IOUS also allows the estimation of place and scope of drainage procedures in cases of overpressure in the pancreatic ducts caused by calcification of the parenchyma or choledocholitiasis in chronic pancreatitis. In pancreatic cancer, IOUS provides a verification of the local extent of tumor-like lesions, allowing for the assessment of pancreatic and lymph nodes metastasis, and indicating the presence of distant and local metastases, including the liver. IOUS significantly improves the effectiveness of intraoperative BAC aspiration or drainage of fluid reservoirs.

Pancreatic surgery: a multidisciplinary assessment of the value of intraoperative US

PURPOSE

To assess the value of intraoperative ultrasonography (US) for different types of pancreatic surgery.

MATERIALS AND METHODS

An institutional review board-approved, HIPAA-compliant retrospective review with waiver of informed consent was performed to evaluate all cases of pancreatic surgery with intraoperative US or laparoscopic US that occurred at a single institution during a 10-year period. Surgical notes, radiologic images, and clinical data for each surgical procedure and subsequent clinical course were reviewed by pancreatic surgeons and radiologists. Presumptive diagnosis, type of surgical procedure performed, and final pathologic data were recorded. A relative value score was established by consensus and assigned to each case with a grade of 0-3, which indicated the value of the intraoperative or laparoscopic US. The type of operation and pathologic data were compared in each of the value score groups. Categoric variables were compared by using either χ(2) or Fisher exact test.

RESULTS

One hundred ninety-three intraoperative or laparoscopic US procedures were performed in 189 patients. Of the patients, there were 102 men and 87 women. The mean age was 57.8 years (range, 18-86 years). Intraoperative or laparoscopic US value scores were as follows: value score 0, 3.6%; value score 1, 11.9%; value score 2, 31.1%; and value score 3, 53.4%. The most common contribution that resulted in a high score (value score 3) was facilitation of technical performance of the surgery (n = 60). High value score was significantly associated with performance of pancreatitis-related surgery (P < .001). The surgical indication that most commonly resulted in a low value score of 0 or 1 was staging of pancreatic cancers. All cases that received a score of 0 occurred in the laparoscopic adenocarcinoma surgical setting (staging or pancreatic biopsy).

CONCLUSION

Intraoperative or laparoscopic US can be a valuable procedure in multiple types of surgical procedures that involve the pancreas and shows clear patterns of value in the different types of surgery.

Intraoperative ultrasonography of the pancreas

Intraoperative ultrasonography (US) of the pancreas is a versatile technique that provides excellent spatial and contrast resolution and real-time imaging capabilities, making it useful for diagnostic imaging as well as for guidance of laparoscopic and open operative procedures. Intraoperative US may be used for applications such as staging and localizing tumors; performing regional metastatic surveys; documenting arterial and venous patency; identifying endocrine tumors; distinguishing pancreatitis from a neoplasm; and guiding biopsy, duct cannulation, and drainage of abscesses or cysts. The scanning approach and technique vary according to the application, with many different equipment and transducer options and sterilization methods available. With increasing clinical demands for intraoperative US, it is essential that radiologists be familiar with its uses and technique. In addition, to properly perform intraoperative US and accurately interpret the images, knowledge of normal and variant pancreatic and vascular anatomy and relevant landmarks is needed. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.307105051/-/DC1.

Ultrasound-guided excision of nonpalpable malignant soft tissue tumors of the abdomen

The use of intraoperative ultrasound to guide the excision of sonographically visible but nonpalpable lesions is a newer modality. Its use in intraoperative localization of recurrent malignant soft tissue tumors has not been reported. This report describes a technique of intraoperative localization by ultrasound to guide the excision of recurrent nonpalpable malignant soft tissue tumors of the abdominal wall in two patients. Tumors of both patients were successfully localized intraoperatively by ultrasonography and excised with adequate margins. This technique leads to reduced patient discomfort and anxiety, the avoidance of organizational requirements on the day of surgery, and allows for adequate margins of resection

Imaging techniques in pancreatic tumors

Conventional ultrasonography represents the first diagnostic imaging modality for the study of pancreatic tumors. Contrast-enhanced ultrasound has significantly improved the accuracy of first-line examination and may influence the choice of second-line investigations: multidetector computed tomography is considered the gold standard for studying pancreatic solid lesions and tumor staging, while MRI with magnetic resonance cholangiopancreatography allows better study of pancreatic cystic lesions and the ductal system. To definitely diagnose a pancreatic lesion, image-guided fine-needle-aspiration or biopsy are very often required. PET with 18-fluorodeoxyglucose, endoscopic ultrasound and intraoperative ultrasonography remain techniques often employed in the third line. This article reviews the imaging techniques generally used for diagnosing the main pancreatic tumors, and a work-up algorithm is finally proposed.

Is intraoperative ultrasound (IOUS) still useful for the detection of liver metastases?

PURPOSE

To evaluate the clinical impact of intraoperative ultrasound (IOUS) in the detection of liver metastases during the years, as compared with those of other imaging modalities.

MATERIALS AND METHODS

All IOUS scans performed for detection of liver metastases from 2000 to 2006 were retrospectively reviewed and compared with the results of preoperative imaging modalities: Ultrasound (US), Computed Tomography (CT), and/or Magnetic Resonance (MR). The number of cases in which IOUS and preoperative imaging studies produced discordant results, in terms of presence/absence of focal liver lesions, was calculated per year. Statistical analysis was performed using the McNemar test. A p value < 0.05 was considered statistically significant.

RESULTS

Eighty-three IOUS scans performed in 2000-2003 were reviewed, and discordance with preoperative imaging findings was found in 19/83 (23%) cases. Of the 42 IOUS scans done during the 2004-2006 period, 10/42 (24%) showed discordance with preoperative studies. All metastases diagnosed with imaging studies were pathologically confirmed. The number of discordant cases in the two periods were not significantly different (p = 0.2).

CONCLUSION

IOUS is still useful in the detection of liver metastases. Its decreased use is probably due to the improved accuracy of preoperative imaging modalities.

Intraoperative ultrasound of the pancreas

Intraoperative ultrasound provides spatial resolution of the pancreas superior to computed tomography, magnetic resonance imaging, and transabdominal sonography. This pictorial essay will review common benign and malignant pancreatic processes including the following: pancreatic ductal adenocarcinoma, pancreatitis, endocrine tumors, mucinous cystic neoplasm, intraductal papillary mucinous neoplasm, serous cystadenoma, and solid pseudopapillary tumor. The use of intraoperative ultrasound in specific surgical situations will be discussed, which include the following: (1) identification of insulinoma(s) which are not detectable preoperatively, (2) identification of the pancreatic duct to determine dissection planes for chronic pancreatitis surgery (eg, Puestow procedure) and for tumor resection, and (3) staging purposes for malignant disease.

Value of contrast-enhanced intraoperative ultrasound for cirrhotic patients with hepatocellular carcinoma: A report of 20 cases

AIM: To assess the clinical value of contrast-enhanced intraoperative ultrasound (CE-IOUS) as a novel tool in partial hepatectomy for cirrhotic patients with hepatocellular carcinoma (HCC).

METHODS: From January 2007 to September 2007, a total of 20 consecutive cirrhotic patients with HCC scheduled to undergo partial hepatectomy were studied. Preoperative contrast enhanced computer tomography (CT) and/or magnetic resonance (MR) scans were performed within 1-2 wk before operation. Intraoperative ultrasound (IOUS) and CE-IOUS were carried out after mobilization of the liver. Lesions on precontrast and postcontrast scans were counted and mapped. CE-IOUS was performed with intravenous injection of ultrasound contrast agents SonoVue (Bracco Imaging, Milan, Italy). Arterial, portal and late phases of contrast enhancement were recorded and analyzed. Nodules showing arterial phase hyper-enhancing and/or hypo-enhancing in late parenchymal phase were considered malignant and removed surgically. Ultrasound-guided biopsy and ethanol ablation would be an option if the nodule could not be removed surgically. Newly detected nodules on IOUS showing iso-enhancement in both arterial and late phases were considered benign. These nodules were either removed surgically if they were close to the main lesion or followed by examinations of alpha-fetoprotein (AFP) level and ultrasound and/or CT/MR every 3 mo.

RESULTS: IOUS found 41 nodules in total, among which 17 (41.46%) were newly detected compared to preoperative imaging. Thirty-three nodules were diagnosed malignant by CE-IOUS, including one missed by IOUS. The sensitivity and specificity of CE-IOUS on detecting HCC nodules are 100% (33/33 and 100% (9/9), respectively. Nine nodules were considered benign by CE-IOUS, four was confirmed at histology and five by follow-up. CE-IOUS changed the surgical strategy in 35% (7/20) of patients and avoid unnecessary intervention in 30% (6/20) of patients.

CONCLUSION: CE-IOUS is a useful means to charac-terize the nodules detected by IOUS in cirrhotic liver, to find isoechoic HCC nodules which can not be shown on IOUS and to improve the accuracy of conventional IOUS, thus it can be used as an essential tool in the surgical treatment of cirrhotic patients with HCC.