Arata Sakai

Chronic Pancreatitis Finding by Endoscopic Ultrasonography in the Pancreatic Parenchyma of Intraductal Papillary Mucinous Neoplasms Is Associated with Invasive Intraductal Papillary Mucinous Carcinoma

Background/Objectives: The recent guideline for intraductal papillary mucinous neoplasms (IPMNs) focuses on morphological features of the lesion as signs of malignant transformation, but ignores the background pancreatic parenchyma, including features of chronic pancreatitis (CP), which is a risk factor for pancreatic malignancies. Endoscopic ultrasonography frequently reveals evidence of CP (EUS-CP findings) in the background pancreatic parenchyma of patients with IPMNs. Therefore, we investigated whether background EUS-CP findings were associated with malignant IPMN. Methods: The clinical data of 69 consecutive patients with IPMNs who underwent preoperative EUS and surgical resection between April 2010 and October 2014 were collected prospectively. The association of EUS-CP findings (total number of EUS-CP findings; 0 vs. ≥1) with invasive IPMN was examined. The association of EUS-CP findings with pathological changes of the background pancreatic parenchyma (atrophy/inflammation/fibrosis) was also examined. Results: Among patients with EUS-CP findings, invasive intraductal papillary mucinous carcinoma (IPMC) was significantly more frequent than among patients without EUS-CP findings (42.5% [17/40] vs. 3.4% [1/29], p = 0.0002). In addition, patients with EUS-CP findings had higher grades of pancreatic atrophy and inflammation than patients without EUS-CP findings (atrophy: 72.5% [29/40] vs. 34.5% [10/29], p = 0.003; inflammation: 45.0% [18/40] vs. 20.7% [6/29], p = 0.04). Conclusions: In IPMN patients, detection of EUS-CP findings in the background pancreatic parenchyma was associated with a higher prevalence of invasive IPMC. Accordingly, EUS examination should not only assess the morphological features of the lesion itself, but also EUS-CP findings in the background parenchyma.

Multifocal cysts and incidence of pancreatic cancer concomitant with intraductal papillary mucinous neoplasm

OBJECTIVES The present study was conducted in order to elucidate the relationship between the number of cyst-existing regions and incidence of pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm (IPMN), which currently remains unclear. METHODS Subjects comprised 141 patients undergoing resection for IPMN (Non-invasive IPMN (IPMN with low-to high-grade dysplasia): N = 94, invasive IPMN: N = 31, and PDAC concomitant with IPMN: N = 16) between November 2000 and February 2017. A logistic regression analysis was performed to assess the relationship between the number of cyst-existing regions (one region/two or more regions) and incidence of PDAC concomitant with IPMN, adjusted by clinical characteristics. Cyst-existing regions were defined by the number of anatomical parts of the pancreas: the head/body/tail of the pancreas. RESULTS Multiple cyst-existing regions (two or more regions) correlated with the incidence of PDAC concomitant with IPMN (PDAC concomitant with IPMN in one region vs. two or more regions: 3/66 vs. 13/75, multivariable odds ratio [OR] = 4.11, 95% confidence interval [CI] = 1.22 to 18.8, P = 0.02). In contrast, multiple cyst-existing regions did not correlate with the incidence of IPMN (invasive IPMN in one region vs. two or more regions: 13/66 vs. 18/75, OR = 1.19, 95% CI = 0.52 to 2.76, P = 0.67). CONCLUSIONS Multifocal cysts correlated with the incidence of PDAC concomitant with IPMN, and may be a high-risk factor for PDAC concomitant with IPMN.

A novel biliary cannulation method for difficult cannulation cases using a unique, uneven, double-lumen cannula (Uneven method)

The utility of pancreatic duct guidewire (P-GW) placement techniques, including the contrast-medium method and the contrast-free wire-guided cannulation method (i. e. the “double-guidewire method” [D-GW]), has been reported for selective biliary cannulation in patients in whom performing cannulation of the bile duct is difficult [1–5]. However, P-GW placement often disturbs the approach to the bile orifice. Moreover, it is sometimes difficult to insert the catheter or guidewire in the direction of the bile duct, which delays biliary cannulation. Herein, we report a novel biliary cannulation method using a unique, uneven, double-lumen cannula (UDLC; PIOLAX, Tokyo, Japan). The UDLC is a double-lumen catheter, with lumens measuring 0.025 and 0.035 inches in diameter, respectively. The orifice of each lumen is uneven, thereby forming a channel at the tip of the UDLC (▶Fig. 1). With such characteristics in mind, we applied the UDLC to develop a new method of selective biliary cannulation for difficult cannulation cases (UDLC method). We describe a case wherein the UDLC was successfully employed without complications (▶Video1). A 75-year-old man presented with pancreatic cancer and was admitted to our hospital for treatment of obstructive cholangitis. It was difficult to perform biliary cannulation as we could insert only the P-GW. Initially, the UDLC was used to intubate the papilla through the P-GW via the distal lumen. This straightened the pancreatic duct and the common channel, thereby effectively stabilizing the papilla (▶Fig. 2). Next, we performed biliary cannulation via the proximal lumen, as is done in the D-GW method (▶Fig. 3). By using this method, we were able to avoid the time delay in adjusting the catheter axis to comply with the bile duct direction, as required in the P-GW method. Thus, we easily initiated the biliary cannulation approach. Ultimately, we succeeded in performing selective biliary cannulation (▶Fig. 4). E-Videos

Serum apolipoprotein A2 isoforms in autoimmune pancreatitis

Recently, apolipoprotein A2 (apoA2) isoforms have been reported as candidate serum/plasma biomarkers of pancreatic cancer. However, the distribution of apoA2 isoforms in patients with autoimmune pancreatitis (AIP) has not been investigated yet. In this study, we evaluated the distribution of serum apoA2 isoforms; i.e., homodimer apoA2-ATQ/ATQ, heterodimer apoA2-ATQ/AT, and homodimer apoA2-AT/AT, in AIP patients and healthy volunteers (HV) using enzyme-linked immunosorbent assays, and the clinical characteristics and serum levels of each apoA2 isoform in 32 AIP patients and 38 HV were investigated. The calculated apoA2-ATQ/AT levels of the AIP patients were significantly lower than those of the HV, which agreed with results obtained for patients with pancreatic cancer. Interestingly, most of the AIP patients exhibited high levels of apoA2-ATQ along with low levels of apoA2-AT, indicating that the processing of the C-terminal regions of apoA2 dimer was inhibited in the AIP patients. This specific distribution of serum apoA2 isoforms might provide important information about the disease states of AIP patients and aid the differential diagnosis of AIP versus pancreatic cancer.