Per oral cholangiopancreatoscopy in pancreatico biliary diseases - Expert consensus statements

Table 1 Detailed evidence levels of respective references are provided for each consensus statement

Consensus statement	Evidence level distribution								Recommendation grade
	1 ++	1 +	1 -	2 ++	2 +	2 -	3	4
1	0	0	0	1	8	1	7	16	B
2	0	0	0	4	15	1	7	9	B
3	0	1	0	1	13	1	5	10	A
4	0	0	0	0	3	2	3	11	C
5	0	0	0	0	2	1	1	7	C
6	0	0	0	0	4	0	3	8	C

Table 2 Consensus statement 1

POCPS is now an important additional tool during ERCP

Recommendation Grade B

Quality of evidence: 2++

Direct visualization and the ability to sample and treat lesions aids in the care of patients by providing the correct diagnosis and allowing definitive treatment of lesions

Cholangiopancreatoscopy through an ERCP catheter is a simple, safe and effective procedure for diagnosing pancreatobiliary diseases

Intraductal peroral cholangioscopy and pancreatoscopy-sampling techniques appear to offer an advantage over fluoscopy-guided ERCP sampling techniques for the diagnosis of pancreatobiliary lesions

POCPS: Peroral cholangiopancreatoscopy; ERCP: Endoscopic retrograde cholangiopancreatography.

Table 3 Consensus statement 2

In patients with indeterminate biliary strictures, POCS and POCS-guided targeted biopsy is useful for establishing a definitive diagnosis

Recommendation Grade B

Quality of evidence: 2++

Technical success: Technical success for POCS with or without POCS-guided biopsy is reported to be 66% to 95% when defined as ability to reach the targeted lesion and, if desired, obtain a biopsy adequate for histopathology

Diagnostic accuracy: Diagnostic measures of POCS with or without POCS-guided biopsy for malignancy were explicitly reported for a total of 980 cases in 11 studies. Reported sensitivity ranged from 49% to 100% and specificity ranged from 77% to 100%. In three prospective trials reporting separately on POCS alone and on POCS-guided biopsy and representing 297 patients, the weighted average sensitivity and specificity were 83% and 96% for POCS alone and were lower at 56% and 81% for POCS-guided biopsy

Intrinsic vs extrinsic strictures: POCS-guided biopsy is significantly higher for intrinsic than extrinsic tumors, and may be particularly useful in PSC patients prior to liver transplantation

POCS findings in indeterminate strictures: Findings of POCS such as tortuous and irregularly dilated vessels, intraductal nodules or masses, infiltrative or ulcerated strictures, and papillary or villous mucosal projections are reported to be associated with malignancy. Generally POCS is reported to improve yield of associated ERCP-guided biopsy. POCS with NBI was reported to significantly improve diagnostic accuracy over white light POCS

Altered patient management: Changed patient management following POCS is reported in as many as 2/3 of patients when measured. Impact of POCS on pre-operative diagnosis may impact a surgical decision. POCS combined with IDUS was reported useful in guiding patient management in portal biliopathy. POCS was also reported useful for assessment of anastomotic strictures after liver transplantation

Complications: Reported overall complication rates range from 6.6% to 9%. The most common complication is cholangitis, reported in approximately 5% of cases. There is one report of fatal cholangitis

POCS: Peroral cholangioscopy; PSC: Primary sclerosing cholangitis; ERCP: Endoscopic retrograde cholangiopancreatography; NBI: Narrow band imaging; IDUS: Intraductal ultrasonography.

Table 4 Summary of diagnostic accuracy parameters reported in relevant references

Ref.	Grading	Article type	Sensitivity	Specificity	Positive predictive value	Negative predictive value
[34]	4	Review	92%	93%	89%	95%
[12]	2+	Prospective	78%	82%	49%	98%
[13]	2+	Prospective	95%	79%	82%	82%
[21]	2++	Prospective	100%	77%	71%	100%
[35]	2+	Prospective	NR	NR	88%	94%
[14]	2+	Prospective	NR	NR	89%	96%
[15]	4	Retrospective	66%	98%	NR	NR
[26]	2+	Retrospective	98%	90%	NR	NR
[32]	2+	Retrospective	57%	100%	NR	NR
[36]	2+	Retrospective	77%	NR	NR	NR
[37]	2++	Prospective	99%	96%	99%	95.8%
[38]	2+	Prospective	NR	NR	100% visual	92% visual
					38% biopsy	100% biopsy

NR: Not reported.

Table 5 Consensus statement 3

POCS and POCS-guided lithotripsy is recommended for treatment of difficult CBD stones when standard techniques fail

Recommendation Grade A

Quality of evidence: 1+

Technical success: Technical success for POCS and POCS-guided lithotripsy for the treatment of difficult CBD stones when standard techniques fail range from 71%-100%

Direct visualization advantage: One of the key therapeutic benefits of POCS is the capacity to directly visualize and treat large intraductal stones. Studies show that nearly all bile duct stones which failed conventional endoscopic removal (5%-10% of patients) could be removed non-surgically using POCS and POCS-guided lithotripsy

Residual stone detection: The diagnosis of small bile duct stones can be difficult with an ERCP. In those cases, POCS is able to detect residual stones missed on routine ERCP.

Complications: The most common complication reported is cholangitis (4.0%). Reported overall complications rates range from 3.8% to 13.3%

The results support the non-surgical management of difficult bile duct stones, particularly in patients at high risk for surgery

POCS: Peroral cholangioscopy; CBD: Common bile duct; ERCP: Endoscopic retrograde cholangiopancreatography.

Table 6 Consensus statement 4

In patients with main duct IPMN POPS may be used to assess the extent of tumor to assist surgical resection

Recommendation Grade C

Quality of evidence: 2+

Technical success: Technical success for POPS in patients with IPMN is reported between 73% and 92% when defined as ability to reach and examine the targeted lesion

Diagnostic accuracy: Diagnostic measures of POPS with or without POPS-guided biopsy for malignancy in IPMN are rarely reported in detail, and range from 50% to 68% sensitivity and from 87% to 100% specificity. Diagnostic accuracy seems better in main duct IPMN than in side branch IPMN

POPS findings in IPMN: The most commonly reported POPS findings associated with malignancy in IPMN are villous patterns and vascular images Granular mucosa and fish-like patterns without vascularity were not associated with malignancy

POPS and IDUS: Some studies document enhanced diagnostic accuracy when POPS is combined with endosonographic measures, particularly IDUS

Pre-operative and intra-operative POPS: The role of POPS to pre-operatively provide diagnostic information on malignancy and to pre-operatively and/or intra-operatively document the location and extent of dysplastic IPMN is generally reported

IPMN: Intraductal papillary mucinous neoplasms; POPS: Peroral pancreatoscopy; IDUS: Intraductal ultrasonography.

Table 7 Consensus statement 5

In difficult pancreatic ductal stones, POPS-guided lithotripsy may be useful in fragmentation and extraction of stones

Recommendation Grade C

Quality of evidence: 2+

POPS-guided EHL or laser lithotripsy: EHL was reported for 17 cases, with stone clearance reported in 71% (12/17). Laser lithotripsy was reported for 9 cases, with stone clearance reported in 100% (9/9). Stone clearance was reported in 70% (32/46) with EHL or laser lithotripsy in 39 of those cases

POPS-guided EHL vs ESWL: POPS-guided EHL compared to ESWL for treatment of pancreatic duct stones is reported as difficult and as being only rarely indicated

POPS: Peroral pancreatoscopy; EHL: Electrohydraulic lithotripsy; ESWL: Extracorporeal shock-wave lithotripsy.

Table 8 Consensus statement 6

Additional indications for POCPS include selective guidewire placement, unexplained hemobilia, assessing intraductal biliary ablation therapy, and extraction of migrated stents

Recommendation Grade C

Quality of evidence: 2+

The primary indications of peroral cholangiopancreatoscopy are indeterminate stricture, indeterminate filling defect and stones, but the application of the technology is vast and is forever expanding. While not many cases are performed and documented, the indications extend to selective guidewire placement, unexplained hemobilia, assessment of intraductal biliary ablation therapy as well as the extraction of migrated stents

These additional indications have been reported in clinical studies as well as comprehensive reviews of POCPS

POCPS: Peroral cholangiopancreatoscopy.