J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website https://www.jocmr.org

Review

Volume 13, Number 9, September 2021, pages 460-465

Incidence of Extrahepatic Portal Vein Anatomic Variations and Their Clinical Implications in Daily Practice

Figures

Figure 1. Normal anatomy of the portal system (type I). RPV: right portal vein; LPV: left portal vein; RaPV: right anterior portal vein; RpPV: right posterior portal vein.

Figure 2. Anatomical variations of the portal vein (a: type II; b: type III; c: type IV; d: type V). RPV: right portal vein; LPV: left portal vein; mPV: main portal vein; RaPV: right anterior portal vein; RpPV: right posterior portal vein.

Figure 3. Flow diagram according to PRISMA guidelines. PRISMA: preferred reporting items for systematic reviews.

Tables

**Table 1.** Common PV Variations as Classified by Covey
Type	Description
MPV: main portal vein; RPV: right portal vein.
Type I	Classical anatomy
Type II	Trifurcation
Type III	Right posterior vein as first branch of MPV
Type IV	Separate origin of segment VII from RPV
Type V	Separate origin of segment VI from RPV

**Table 2.** Classification of the Articles According to the Number of Patients and Type of Study
Author	No. of patients	Type of study
Akgul et al [9]	585	Retrospective
Covey et al [10]	216	Retrospective
Atasoy et al [11]	200	Consecutive
Koc et al [12]	1,384	Retrospective
Okten et al [13]	85	Consecutive
Sureka et al [14]	967	Retrospective
Bayrak et al [15]	278	Consecutive

**Table 3.** Distribution of the Found Anatomic Variations of Portal Vein
Type	Portal vein variant	Number of patients	Percentage
I	Normal	2,795	75.2
II	Trifurcation	356	9.6
III	Right posterior vein as first branch of main portal vein	306	8.2
IV	Segment VII branch as separate branch of right portal vein	49	1.1
V	Segment VI branch as separate branch of right portal vein	33	0.9
	Right anterior portal vein originating from the left portal vein	9	0.24
	Right portal vein trifurcation	8	0.21
	Total ramification	6	0.16
	Absence of portal vein bifurcation	2	0.05
	Left portal vein from right anterior portal vein	4	0.1