• 2019-10
  • 2019-11
  • 2020-03
  • 2020-07
  • 2020-08
  • 2021-03
  • Pathologic analysis PA The resected specimens were histologi


     Pathologic analysis (PA). The resected specimens were histologically examined according to the Verbeke protocol by a specialized pathologist (author A.F.S.) who noted the tumor’s characteristics, including the ori-gin, differentiation grade, maximum diameter, presence of perineural invasion, lymphatic and/or vascular inva-sion and extension in peripancreatic soft tissue (Verbeke et al. 2006). Margins to all pancreatic surfaces were measured. Radicality was assessed as follows: R0, tumor-free; R1, tumor extension <1 mm; or R2, macro-scopically non-radical. In the event that a vascular recon-struction was performed, the borders of the vascular patch and the depth of invasion in the vascular patch or segment were also assessed for tumor involvement. All resected Cucurbitacin I nodes were scored for tumor positivity.
    Assuming that the surgical strategy would be changed in >30% of the patients because of the IOUS assessment, 31 patients should be included. A sample size of 31 patients achieves 80% power using the two-sided McNemar test with a significance level of 0.05.
    Differences between correct assessment of vascular contact between preoperative imaging and IOUS were assessed with a McNemar test.
    Patient characteristics
    During the study period, IOUS was performed in 31 surgical explorations (Table 1). One patient underwent two explorations: six months after a pancreatic head resection, she underwent a pancreatic tail resection for a second primary malignancy. Vascular contact was sus-pected on nine preoperative scans and vascular involve-ment on one scan; therefore, vascular resection was suggested for this patient. Vascular contact could not be determined from four preoperative scans (13%) because of the isodense appearance on the scans. Twenty-seven malignant tumors and one benign lesion were resected, of which four included a vascular resection. During three explorations, resection was abandoned because of irre-sectable disease.
    Primary outcome: Effect of IOUS assessment on surgical strategy
    The IOUS-based characteristics of the tumors are summarized in Table 2. The use of IOUS extended the average procedure by 11 § 5 min. All tumors (100%) were detected with IOUS, and vascular contact was detected in 14 patients (45%). The majority of the tumors were clearly visible, hypoechoic and had irregular borders.
    Next, the effect of IOUS assessment on the surgical procedure was examined. A detailed overview of the
    2022 Ultrasound in Medicine & Biology
    Table 1. Patient characteristics
    female 14 47 Endoscopic ultrasound yes 22 71
    no 26 84 Neoadjuvant treatment gemcitabine 3 10
    none 27 87 Last imaging CT scan 24 77 before surgery visibility: direct sign 11 46
    indirect sign 13 54
    density: hypodense 9 37
    visibility: direct sign 7 100
    indirect sign
    dynamic 2 29 Size (max diameter) measurable 17 55
    Origin and localization ampulla of Vater 3 10 of tumor distal bile duct 4 13
    duodenum 4 13
    proc. uncinatus 2 10
    tail 2 10 Vascular contact of tumor no vascular contact 17 55
    contact with vessel 9 29
    involvement of vessel 1 3
    contact cannot 4 13
    be judged
    Clinical lymph node status N0 24 77
    Type of surgery PPPD/whipple 21 67
    tail resection 3 10
    total pancreatectomy 3 10
    duodenum resection 1 3
    no resection 3 10
    CT = computed tomography; DWI =; IQR = inter quartile range; MRI = magnetic resonance imaging; N0 =; N1 =; PPPD = pylorus pre-serving pancreatoduodectomy; proc. uncinatus = uncinated process; SD = standard deviation; T1 = .