Keywords
Cholangioscopy - Strictures - Pancreatobiliary (ERCP/PTCD) - Stones - Tissue diagnosis
Introduction
Bile duct disorders, particularly indeterminate biliary strictures, are common, yet
they remain difficult to diagnose, which is especially problematic because their management
varies widely depending on the etiology [1]. An accurate, minimally invasive diagnostic procedure can avoid major surgery and
accelerate initiation of the correct treatment, which unfortunately is often the only
option for oncologic patients.
Magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography
(ERCP) are the main diagnostic and therapeutic procedures for biliary duct disorders.
Nevertheless, strong limitations in terms of the ability to accurately differentiate
between malignant and benign pathologies and ineffective therapeutic outcomes with
ERCP in cases of complicated biliary stones have been reported [2]. To overcome limitations of ERCP related to diagnosis and treatment, cholangioscopy
probes were introduced with improved image quality and probe durability [3].
Released in 2015, the SpyGlass DS (Boston Scientific, Marlborough, Massachusetts,
United States), which employs a digital single-operator cholangioscopy (DSOC) technique,
has considerably improved the quality of clinical decisions regarding the diagnosis
and treatment of bile duct disorders [3]. Some well-known therapeutic indications for this procedure include difficult biliary
stone treatment using electrohydraulic (EHL) or laser lithotripsy, foreign body or
migrated stent removal, and guidewire placement [1]. However, this technology has low-quality imaging and elevated costs, which limits
its widespread use [4]. Therefore, technologies with higher image resolution that could improve visual
impression, diagnostic accuracy, and improvements in therapeutics and limit patient
harm are needed.
Physician expertise plays a major role in accurately detecting and differentiating
neoplastic from non-neoplastic lesions based on visual findings and in target lesion
biopsy. In additionally, the adverse events (AEs) of cholangioscopy (bleeding, acute
cholangitis, and pancreatitis) can be a challenge for both experienced and novice
endoscopists [5].
This study aimed to evaluate the usefulness and safety of a novel 9F and 11F DSOC
system (eyeMAX, Micro-Tech, Nanjing, China) in terms of neoplastic diagnostic accuracy
based on visual examination, ability to evaluate tumor extension and to achieve complete
biliary stone clearance, and procedure-related AEs.
Patients and methods
Study design and ethical review
This was a single-center study performed at the Instituto Ecuatoriano de Enfermedades
Digestivas (IECED), Guayaquil, Ecuador. The study protocol was approved by the Institutional
Review Board and was conducted according to the Declaration of Helsinki and the STROBE
Statement. Patients or their legal guardians provided written informed consent before
the procedures for analysis and publication of the DSOC procedure.
Study population
Two patient cohorts were created based on whether diagnosis or therapy was applied
in order to assess the diagnostic and therapeutic potential of the eyeMAX system.
Data from patients aged at least 18 years who underwent DSOC from July 2021 to April
2022 were retrospectively collected.
The diagnostic cohort included patients with suspected malignancy and indeterminate
strictures (malignant or benign) based on previous contrast-enhanced computed tomography
(CE-CT), MRCP or inconclusive endoscopic ultrasound (EUS) with fine-needle aspiration/biopsy
(FNA/B).
The therapeutic cohort included patients with biliary stones (> 20 mm) or with biliary
stones that were unable to be resolved with EHL. At the end of biliary stone removal,
cholangioscopy was performed to record biliary stone clearance. Patients with uncontrolled
coagulopathy, who were pregnant/lactating, who were allergic to the contrast medium,
who could not pass the scope, or who were followed-up for < 6 months were excluded
from the study.
eyeMAX system description
eyeMAX is a single-use, single-operator-controlled video pancreaticobiliary scope
measuring 220 cm in length and available in two diameters, 9F and 11F, with an irrigation
channel, an optical channel, and 1.2-mm and 2.0-mm accessory channels, respectively.
Given the option of a probe with a diameter smaller than that of the existing cholangioscope
(10.5F SpyGlass probe, Boston Scientific, Marlborough, Massachusetts, United States)
that retains the 1.2-mm working channel, lower-caliber cholangioscopes could offer
advantages in assessing biliary tree strictures and the extension of lesions and in
providing adequate stent choices.
The eyeMAX probe consists of a high-resolution imaging sensor with a fiberoptic illumination
bundle and a full high definition+ image. The white balance adjustment function of
the camera provides a more natural color space in the image that is not affected by
the light source color. The eyeMAX system has image processing algorithms and an illumination
design that grants the complementary metal oxide semiconductor image sensor high-resolution
capabilities. In addition, the system has a forward 120° field of view. The eyeMAX
biopsy forceps (Micro-Tech, Nanjing, China) is a single-use device that passes through
the biopsy channel of the scope with a working length of 2900 mm and opening widths
of 3 mm and 4.5 mm for the 9F and 11F probes, respectively. The handle of the cholangioscope
allows four-way tip deflection, providing optimal mobility through the biliary tract.
Endoscopic techniques
All enrolled patients were evaluated by standard gastroduodenoscopy (Pentax ED 34-I10T;
Pentax Medical, Hoya Corps., Tokyo, Japan), Pentax video processing (EPK-I7010), and
the new eyeMAX system (Micro-Tech, Nanjing, China).
All procedures were performed under general anesthesia with antibiotic prophylaxis
(1 g
ceftriaxone, intravenously) and executed by experienced endoscopists (C.R.M., J.A.V.,
I.R.,
and M.K.), who have conducted > 300 ERCP procedures per year and are experienced in
peroral cholangioscopy (POCS) (> 150 per year) and were blinded to previous imaging.
Prior to the initial DSOC, an endoscopic sphincterotomy was performed to allow passage
of
the eyeMAX probe through the biliary sphincter. Using an over-the-wire technique,
biliary
cannulation was achieved. Then, the probe was passed inside the biliary tract using
suction
to clear bile and contrast material; sterile saline solution was continuously infused
for
imaging optimization. The size of the cholangioscope (9F or 11F) used during the procedure
was based on the judgment of the experienced endoscopists. Images and videos were
recorded
using a high-definition image capture system ([Video 1]
a). Balloon dilation or sphincterotomy extension also was
performed in subsequent DSOC sessions if needed. At least three tissue biopsies were
performed using eyeMAX biopsy forceps (Micro-Tech, Nanjing, China) through the
cholangioscope from each suspicious area found within the biliary duct system.
a Representative video of a 70-year-old female with bile duct stenosis assessed with
a 9F eyeMAX DSOC system.
b Diagnosis and treatment of a biliary stone in the common hepatic duct by using the
11F eyeMAX DSOC system.Video 1
EHL was performed in patients with complicated biliary stones refractory to conventional
methods of extraction during ERCP using highly flexible bipolar 3F (1 mm) or 4.5F
(1.5 mm) lithotripsy probes compatible with a Lithotron generator (Walz Elektronik
GmbH, Germany). Because the lithotripsy probes are available in two diameters, unlike
the 1.9F probe compatible with the AUTOLITH Touch generator (Boston Scientific, Marlborough,
Massachusetts, United States), which is available in only a single dimension, the
lithotripsy probes could be used with both the 9F and 11F eyeMAX cholangioscopes,
with the power proportional to the diameter of the probe, which is extremely useful
in patients with stones and strictures. Despite the high flexibility of the Lithotron-compatible
EHL probes and use of a probe tip specifically designed for reproducibly delivering
shockwaves, the probes can maintain their positions outside the cholangioscope. All
procedures took place in normal saline medium. The lithotripsy probe was positioned
past the working channel of the scope and in contact with the stone. The stone was
then fragmented by microshock waves generated by short high-voltage energy pulses.
Microliquid jets and the microshock waves exert high dual effectiveness, while the
minimized tensile phases and short range of the microwaves with steep edges prevented
damage to the surrounding tissue. At the end of the procedure, the stones were retrieved
with a conventional balloon extraction device ([Video 1]
b).
Adverse events
AEs were defined following the American Society for Gastrointestinal Endoscopy (ASGE)
criteria [5]. Perforation, acute pancreatitis, cholangitis, and bleeding were categorized as
major AEs and were recorded up to 30 days after the procedure. Perforation was defined
as the presence of air or luminal content outside the gastrointestinal tract. Post-ERCP
pancreatitis was defined as abdominal pain with a 3-fold increase in serum amylase/lipase
24 hours to 2 weeks after the procedure. Postprocedure cholangitis was defined as
the presence of fever (> 38°C), jaundice, and abdominal pain persisting for more than
24 hours. Bleeding was defined as the presence of hematemesis and/or melena or a hemoglobin
drop > 2 g/dL.
Cholangioscopic features of neoplastic and non-neoplastic lesions.
The presence of neovascularization was the only macroscopic feature of the suspected
malignant lesions that we took into consideration, corresponding to “spider vascularizations”
and “tortuous and dilated vessels” common features encountered in neoplastic lesions
as described in the Carlos Robles-Medranda (CRM) et al classification [6] and in the Mendoza criteria [7], respectively. Both classification systems are detailed in [Table 1]. Histological evaluation was used as the gold standard for diagnosis.
Table 1 Peroral cholangioscopy macroscopic classification system for nonneoplastic and neoplastic
common bile duct lesions: Carlos Robles-Medranda Classification and Mendoza criteria.
|
Carlos Robles-Medranda classification
|
|
Nonneoplastic lesions
|
|
Type 1
|
Villous pattern
|
A. Micronodule or
B. Villous pattern without vascularity
|
|
Type 2
|
Polypoid pattern
|
A. Adenoma or
B. Granuloma pattern without vascularity
|
|
Type 3
|
Inflammatory pattern
|
Regular or irregular fibrous and congestive pattern with regular vascularity
|
|
Neoplastic lesions
|
|
Type 1
|
Flat pattern
|
Flat and smooth or irregular surface with irregular or spider vascularity and no ulcerations
|
|
Type 2
|
Polypoid pattern
|
Polypoid with fibrosis and irregular or spider vascularity
|
|
Type 3
|
Ulcerated pattern
|
Irregular ulcerated and infiltrative pattern with or without fibrosis and with irregular
or spider vascularity
|
|
Type 4
|
Honeycomb pattern
|
Fibrous honeycomb pattern with or without irregular or spider vascularity
|
|
Mendoza criteria
|
|
Tortuous and dilated vessels
|
|
Irregular nodulations
|
|
Raised intraductal lesion
|
|
Irregular surface with or without ulcerations
|
|
Friability
|
Statistical analysis
Statistical analysis was performed using R v4.1.2 (R Foundation for Statistical Computing,
Posit PBC, Vienna, Austria) by our institutional biostatistician (M.P-T.). Continuous
variables are described as the mean (standard deviation, SD) or median (interquartile
range [IQR]) depending on their statistical distribution as assessed with the Kolmogorov-Smirnov
test. Categorical variables are described as frequencies (%) with 95% confidence intervals.
Diagnostic accuracy, which was defined as the sensitivity, specificity, positive predictive
value (PPV) and negative predictive value (NPV), and observed agreement, was calculated
for the eyeMAX visual impression and eyeMAX-guided biopsy. Histological findings were
considered the gold standard. P < 0.05 was considered statistically significant.
Results
Overall patient characteristics
A total of 80 patients underwent DSOC during the study period, were included in the
study, and distributed into two groups based on the type of procedure performed: 49
underwent diagnostic procedures and 43 underwent therapeutic procedures. The median
age was 62.5 years (range, 44.3–72.0), and 36 of 80 patients (45.0%) were female.
A total of 36 of 80 patients had previously undergone ERCP procedures.
Diagnostic cohort
The median age of the patients in the diagnostic cohort was 61.0 years (range, 48.0–69.0),
and 21 (42.9%) were female. The diagnostic cohort baseline characteristics are summarized
in [Table 2]. The neovascularity pattern was identified in 23 of 49 patients (46.9%) with suspected
malignant visual impression ([Fig. 1]); biopsies from this area confirmed the diagnosis of cholangiocarcinoma in 20 of
32 patients, intrapapillary mucinous neoplasia (IPMN) was confirmed in two patients,
and secondary malignant infiltration was identified in one patient. Eight patients
had a final benign diagnosis, six of eight patients had inflammatory lesions, and
two patients had IgG4-related cholangitis. The histopathological results were inconclusive
for one patient.
Table 2 Baseline characteristics of the diagnostic cohort.
|
Patient characteristics
|
11F (n =17)
|
9F (n =32)
|
Total (n = 49)
|
|
IQR, interquartile range; ERCP, endoscopic retrograde cholangiopancreatography; IPMN,
intrapapillary mucinous neoplasia.
*Evaluated in patients with cholangiocarcinoma (20/32).
|
|
Age (years), median (IQR)
|
66.0 (58.0–74.0)
|
60.0 (35.8–68.3)
|
61.0 (48.0–69.0)
|
|
Young adults (18–39 y), n (%)
|
1 (5.9)
|
9 (28.1)
|
10 (20.4)
|
|
Middle-aged adults (40–64 y), n (%)
|
6 (35.3%)
|
13 (40.6%)
|
19 (38.8)
|
|
Elderly adults (≥ 65 y), n (%)
|
10 (58.8%)
|
10 (31.3%)
|
20 (40.8)
|
|
Sex (female), n (%)
|
5 (29.4%)
|
16 (50.0%)
|
21 (42.9)
|
|
Previous ERCP, n (%)
|
6 (35.3%)
|
10 (31.3%)
|
16 (32.7)
|
|
Indication, n (%)
|
|
Undetermined bile duct stenosis
|
0 (0%)
|
8 (25.0%)
|
8 (16.3)
|
|
Suspicion of bile duct neoplastic lesion
|
9 (52.9%)
|
14 (43.8%)
|
23 (46.9)
|
|
Filling defect
|
4 (23.5%)
|
3 (9.4%)
|
7 (14.3)
|
|
Postsurgical stricture
|
4 (23.5%)
|
3 (9.4%)
|
7 (14.3)
|
|
Pancreatic duct stricture
|
0 (0%)
|
4 (12.5%)
|
4 (8.2)
|
|
Follow-up status
|
|
Alive
|
8 (47.1%)
|
17 (53.1%)
|
25 (51.0)
|
|
Dead
|
9 (52.9%)
|
15 (46.9%)
|
24 (49.0)
|
|
Procedure
|
|
Lesion location, n (%)
|
|
Common bile duct
|
5 (29.4%)
|
15 (46.9%)
|
20 (40.8)
|
|
Common hepatic duct
|
5 (29.4%)
|
6 (18.8%)
|
11 (22.4)
|
|
Hepatic hilum
|
6 (35.3%)
|
5 (15.6%)
|
11 (22.4)
|
|
Right intrahepatic duct
|
0 (0%)
|
1 (3.1%)
|
1 (2.0)
|
|
Left intrahepatic duct
|
1 (5.9%)
|
1 (3.1%)
|
2 (4.1)
|
|
Main pancreatic duct
|
0 (0%)
|
4 (12.5%)
|
4 (8.3)
|
|
Neovascular visualization (yes), n (%)
|
9 (52.9%)
|
14 (43.8%)
|
23 (46.9)
|
|
Cholangioscope passed through stenosis, n (%)*
|
|
Yes
|
–
|
9 (28.1)
|
9 (45.0)
|
|
No
|
6 (35.3)
|
5 (15.6)
|
11 (55.0)
|
|
Biopsy and histology
|
|
Biopsy performed (yes), n (%)
|
11 (64.7%)
|
21 (65.6%)
|
32 (65.3)
|
|
Biopsies performed, n (%)
|
|
3
|
1 (5.9%)
|
2 (6.3%)
|
3/32
|
|
4
|
2 (11.8%)
|
11 (34.4%)
|
13/32
|
|
5
|
1 (5.9%)
|
1 (3.1%)
|
2/32
|
|
6
|
7 (41.2%)
|
7 (21.9%)
|
14/32
|
|
Adequate biopsy, n (%)
|
11 (64.7%)
|
20 (62.5%)
|
31/32 (96.8)
|
|
Histopathological diagnosis, n (%)
|
|
Inflammation
|
2 (11.8%)
|
4 (12.5%)
|
6 (18.8)
|
|
Cholangiocarcinoma
|
8 (47.1%)
|
12 (37.5%)
|
20 (62.5)
|
|
Secondary malignant infiltration
|
0 (0%)
|
1 (3.1%)
|
1 (3.1)
|
|
IgG4
|
0 (0%)
|
2 (6.3%)
|
2 (6.2)
|
|
IPMN
|
1 (5.9%)
|
1 (3.1%)
|
2 (6.2)
|
|
Inconclusive
|
0 (0%)
|
1 (3.1%)
|
1 (3.1)
|
Fig. 1 Representative image of a patient with a neoplastic lesion. a A malignant biliary stricture with dilated and tortuous vessels as observed with
the eyeMAX DSOC system. b Lesion detected during endoscopic ultrasound. c Fluoroscopic image showing the bile duct stricture. d Fluoroscopic image showing the stent placed in the bile duct. e Pathology image using hematoxylin and eosin stain.
A 9F cholangioscope was used in 32 patients from the diagnostic cohort. Tumor extension
could be documented in nine patients using this cholangioscope by passing the site
of stenosis, which was not possible with the 11F device. In addition, evaluation of
the main pancreatic duct was achieved in four patients with pancreatic duct stenosis
by using the 9F cholangioscope, after a failed 11F cholangioscope cannulation.
The neoplastic diagnostic accuracy of the DSOC device was assessed in terms of sensitivity,
specificity, PPV, NPV and observed agreement. Visual examination using the eyeMAX
cholangioscope achieved 91.6% sensitivity, 87.5% specificity, 95.6% PPV, 77.8% NPV,
and 90.1% observed agreement. In addition, we evaluated the diagnostic accuracy of
the DSOC-guided biopsy, which achieved a sensitivity, specificity, PPV, NPV, and observed
agreement of 95.8%, 100%, 100%, 100%, and 96.9%, respectively.
Therapeutic cohort
The median age of the patients in the therapeutic cohort was 66 years (range, 35.0–75.0),
and 20 (46.5%) were female. Total stone clearance was achieved in 22 of 31 patients
(71.0%) during the first session. Six patients needed an additional EHL session for
complete biliary stone extraction. Ten patients required additional procedures, such
as balloon dilation (9/10) and sphincterotomy extension (1/10). The main findings
of this cohort are summarized in [Table 3].
Table 3 Baseline characteristics of the therapeutic cohort.
|
Patient characteristics
|
11F (n = 22)
|
9F (n = 21)
|
Total (n = 43)
|
|
IQR, interquartile range; ERCP, endoscopic retrograde cholangiopancreatography.
|
|
Age (years), median (IQR)
|
67.0 (38.3–75.5)
|
59.0 (30.0–72.0)
|
66.0 (35.0–75.0)
|
|
≤ 18 years, n (%)
|
–
|
1 (4.8%)
|
1 (2.3)
|
|
Young adults (18–39 y), n (%)
|
7 (31.8%)
|
8 (38.1%)
|
15 (34.9)
|
|
Middle-aged adults (40–64 y), n (%)
|
2 (9.1%)
|
2 (9.5%)
|
4 (9.3)
|
|
Elderly adults (≥ 65 y), n (%)
|
13 (59.1%)
|
10 (47.6%)
|
23 (53.5)
|
|
Sex (female), n (%)
|
12 (54.5%)
|
8 (38.1%)
|
20 (46.5)
|
|
Previous ERCP (yes), n (%)
|
13 (59.1%)
|
13 (61.9%)
|
26 (60.5)
|
|
Indication, n (%)
|
|
Anastomotic stenosis
|
1 (4.5%)
|
5 (23.8%)
|
6 (14.0)
|
|
Lithotripsy
|
17 (77.3%)
|
9 (42.9%)
|
26 (60.5)
|
|
Lithotripsy with proximal migration of biliary stent
|
3 (13.6%)
|
2 (9.5%)
|
5 (11.6)
|
|
Proximal migration of biliary stent
|
1 (4.5%)
|
-
|
1 (2.3)
|
|
Radiofrequency ablation
|
–
|
5 (23.8%)
|
5 (11.6)
|
|
Procedure
|
|
Stone location, n (%)
|
|
Both intrahepatic ducts
|
–
|
1 (4.8%)
|
1 (3.2)
|
|
Common bile duct
|
11 (50.0%)
|
6 (28.6%)
|
17 (54.8)
|
|
Common hepatic duct
|
1 (4.5%)
|
3 (14.3%)
|
4 (12.9)
|
|
Cystic duct
|
1 (4.5%)
|
–
|
1 (3.2)
|
|
Hepatic hilum
|
1 (4.5%)
|
–
|
1 (3.2)
|
|
Right or Left Intrahepatic Duct
|
6 (27.3%)
|
–
|
6 (19.4)
|
|
Pancreatic duct
|
1 (4.8%)
|
1 (4.8%)
|
1 (3.2)
|
|
No. stones, n (%)
|
(20/22)
|
(11/21)
|
(31/43)
|
|
1
|
9 (45.0)
|
7 (63.6)
|
16/31 (51.6)
|
|
2
|
2 (10.0)
|
1 (9.1)
|
3/31 (9.7)
|
|
3
|
4 (20.0)
|
1 (9.1)
|
5/31 (16.1)
|
|
4
|
4 (20.0)
|
1 (9.1)
|
5/31 (16.1)
|
|
5
|
1 (5.0)
|
–
|
1/31 (3.2)
|
|
6
|
–
|
1 (9.1)
|
1/31 (3.2)
|
|
Stone size (mm), median (IQR)
|
20.0 (17.5–21.0)
|
20.0 (15.0–20.0)
|
20.0 (15.5–21.0)
|
|
Stone removal, n (%)
|
|
No
|
1 (4.5%)
|
2 (9.5%)
|
3/31 (9.7)
|
|
Partial
|
6 (27.3%)
|
–
|
6/31 (19.4)
|
|
Total
|
13 (59.1%)
|
9 (42.9%)
|
22/31 (71.0)
|
|
Additional procedures, n (%)
|
6 (27.3%)
|
4 (19.0%)
|
10 (32.3)
|
|
Balloon dilation
|
5 (83.3)
|
4 (100%)
|
9 (90.0%)
|
|
Sphincterotomy extension
|
1 (16.7%)
|
–
|
1 (10.0%)
|
|
Clinical success, n (%)
|
21 (95.5%)
|
21 (100%)
|
42 (97.6)
|
|
Early adverse events (No.), n (%)
|
22 (100%)
|
21 (100%)
|
43 (100)
|
|
Late adverse events (No.), n (%)
|
22 (100%)
|
21 (100%)
|
43 (100)
|
Adverse events
No AEs were reported during or after either (diagnostic or therapeutic) DSOC procedure.
No pancreas-related complications were developed following main pancreatic duct evaluation.
Furthermore, no hospital readmissions related to the procedures were registered.
Discussion
This study evaluated the diagnostic accuracy of the novel 9F and 11F DSOC probes in
detecting neoplastic lesions and extension of biliary duct lesions, along with their
safety profile in biliary stone removal. Using the CRM and the Mendoza visual systems
for classifying biliary lesions with the new eyeMAX [6]
[7], we observed high diagnostic accuracy based on good visualization of neovascular
structures (91.6% sensitivity, 87.5% specificity, 95.6% PPV, 77.8% NPV, and 90.1%
observed agreement) and achieved total stone removal in 71.0% of patients in the first
session without AEs.
Indeterminate biliary strictures have long posed diagnostic challenges. Traditional
endoscopic methods like EUS with FNA/B, while useful, are limited to distal lesions
and carry tumor seeding risks [6]
[8]. ERCP brush cytology and fluoroscopy-guided biopsies offer limited sensitivity (45.0%
and 48.0% respectively) and high specificity but are not fully reliable for malignant
diagnoses [8]. Advances in POCS devices have improved diagnostic accuracy with targeted biopsies
showing 64% to 86% sensitivity and 89% to 100% specificity [9]
[10]
[11]
[12]. Integration of cholangioscopy into brush cytology and fluoroscopy-guided biopsies
has further enhanced diagnostic sensitivity [13]
[14]. The Monaco and CRM classifications, based on cholangioscopic findings, have standardized
assessments, achieving 70% to 90% diagnostic accuracy with similar interobserver agreement
[6]
[15]. The introduction of high-quality imaging cholangioscopes has furthered the role
of DSOC in diagnosing biliary lesions. In this study, eyeMAX achieved high diagnostic
accuracy (90.1% and 96.9%) for indeterminate strictures. Previous studies confirm
DSOC’s high sensitivity and specificity, with features like tumoral vessels and infiltrative
strictures indicating malignancy. Previous studies confirm DSOC’s high sensitivity
and specificity with features like tumoral vessels and infiltrative strictures indicating
malignancy [4]
[9]
[16]
[17]
[18]. Robles-Medranda et al. reported 94.5% accuracy using DSOC with the CRM classification,
comparable to other cholangioscopes, underscoring the effectiveness of these advancements
in biliary lesion diagnosis [1].
In this study, tissue biopsies were successfully conducted using the 3-mm opening
width biopsy forceps (9F probe) of the eyeMAX cholangioscope, yielding conclusive
histologic results in 96.9% of cases, despite the smaller opening width. This approach
was particularly effective in confirming IPMN in two patients, underscoring the value
of pancreatoscopy in diagnosing and assessing pancreatic duct strictures, especially
in chronic pancreatitis. A retrospective study further supported pancreatoscopy’s
diagnostic accuracy, with an 87% success rate in distinguishing neoplastic from non-neoplastic
lesions, and enhanced sensitivity and specificity when combined with tissue biopsy
[19]
[20]. In addition, the risk of post-procedure acute pancreatitis could be reduced due
to the proportionality between the pancreatic duct’s diameter and the probe’s diameter
[19]. The cholangioscope design also facilitated deeper pancreatic evaluation and lithotripsy
for pancreatic duct stone treatment, highlighting its increased maneuverability and
therapeutic versatility.
ERCP is the standard for treating biliary stones, achieving 87% to 100% clearance
rates [21]. However, large or multiple stones often require multiple ERCP sessions, making
EHL essential. Cholangioscopy-directed EHL has a 100% success rate following conventional
ERCP failure [22]. A multicenter study involving 407 patients reported a 74.5% first-session clearance
rate with EHL, increasing to 96.7% after all sessions, with multiple sessions influenced
by biliary anatomy, cannulation, and stone size [23]. Stone dimensions > 20 mm or multiple stones often lead to partial clearance during
EHL via DSOC [1]. Robles-Medranda et al. achieved 66.1% clearance in a single session using a SpyGlass
cholangioscope, with a total rate of 94.9% after an additional procedure [3]. This study achieved 71% clearance in the first session, potentially influenced
by different lithotripsy probes, power settings, and the smaller cohort size. The
enhanced efficiency is attributed to the 9F cholangioscope shorter stroke, higher
power of a smaller-diameter probe, and increase maneuverability. No AEs were noted,
possibly due to the smaller cholangioscope diameter, high operator expertise, and
small patient sample. Clinical success was reported in 96.7% of patients with pain
and jaundice, with complete clearance and technical success in all but one patient,
who was referred to surgery due to multiple intrahepatic biliary stones.
The main advantages of this device are its image quality and the availability of two
scope diameters. Both models (9F and 11F) have the same image quality, with no differences
reported by the users. The smaller cholangioscope is easier to handle at the insertion
in the duodenoscope working channel, with simpler maneuverability inside the biliary
tract compared with the 11F cholangioscope. On the other hand, the latter cholangioscope
has a stronger suction function due to the bigger diameter of the working channel,
which could be beneficial in cases in which suction and removal structures, such as
stones > 20 mm, are required. Moreover, it is important to mention the low price
of the device, which can help make it more widely available. The main limitation of
the present study is the small sample size and, therefore, additional studies that
evaluate this product in a large cohort of patients are needed to further validate
these findings.
Conclusions
In conclusion, eyeMAX DSOC performs well in distinguishing neoplastic-biliary lesions
from non-neoplastic lesions along with their extension and is highly effective as
a therapeutic procedure in the total removal of biliary stones with no documented
AEs. Future prospective studies should be performed to compare image quality, maneuverability,
cost-effectiveness, and endoscopist acceptance between the eyeMAX system and currently
available cholangioscopy systems.
