Mesenteric vascular variations and Henle’s trunk anatomy in right colon cancer surgery: implications for complete mesocolic excision and D2 lymphadenectomy

Abstract

Background:

Complete mesocolic excision (CME) with central lymphadenectomy represents the oncologic standard for right colon cancer surgery. However, vascular anatomical variability particularly involving the superior mesenteric vessels and Henle’s gastrocolic trunk may substantially increase operative complexity and hemorrhagic risk. This study aimed to evaluate mesenteric vascular variations systematically and to analyze their implications for the quality and safety of CME/D2 right hemicolectomy.

Materials and methods:

A retrospective descriptive single-center study was conducted at a tertiary referral university hospital. A total of 250 consecutive patients who underwent oncologic right hemicolectomy for histologically confirmed adenocarcinoma of the right colon between January 2020 and January 2025 were included. Clinical, radiological, operative, pathological, and postoperative data were analyzed. Mesenteric vascular anatomy was evaluated using CT angiography (available in 51.2% of cases) and correlated with intraoperative observations. The study was reported according to the STROBE criteria.

Results:

The mean patient age was 64.5 ± 11.2 years (range 28–89) with slight female predominance (55.2%). Complicated presentations (obstruction, perforation, hemorrhage) occurred in 31.2% of cases. CT angiography was available for 128/250 patients (51.2%); its incomplete use was primarily attributable to emergency/complicated presentations (41.0% of the 122 non-angiography cases), resource/protocol constraints (34.4%), and adequate standard CT for planning (24.6%). The ileocolic and middle colic arteries were invariably present. The right colic artery was absent in 35.2% of patients, with variable origins when present. Henle’s trunk was identified in 59.2% of patients, with three distinct venous configurations characterized. Open surgery was performed in 67.2% of cases. No major intraoperative vascular injury was recorded. Adequate lymph node harvest (≥12 nodes) was achieved in all patients (mean 24.6 ± 6.8 nodes). Anastomotic leakage occurred in 2.4% and 30-day mortality in 0.8%.

Conclusion:

Mesenteric vascular variations are the rule rather than the exception during right colon cancer surgery. Preoperative CT angiography with vascular reconstruction appears to facilitate operative planning and anatomical orientation during CME/D2 lymphadenectomy. Standardized vascular-oriented dissection may improve oncologic quality while minimizing vascular complications.

Introduction

Colorectal cancer remains one of the leading causes of cancer-related morbidity and mortality worldwide, with an estimated 1.9 million new cases and nearly 935 000 deaths recorded in 2020 alone^[1^]. Right-sided colon cancers represent a distinct oncologic and surgical entity, characterized by specific embryological, anatomical, and biological features^[2^].

Complete mesocolic excision (CME) with central vascular ligation and D2 lymphadenectomy has progressively emerged as the oncologic standard for right colon cancer surgery, aiming to maximize lymph node clearance along the named mesenteric vessels and to improve long-term oncologic outcomes^[3,4^]. This approach, which mirrors the embryological planes of the mesocolon, requires precise anatomical knowledge and careful dissection around the superior mesenteric artery (SMA) and superior mesenteric vein (SMV).

The vascular anatomy of the superior mesenteric territory, however, demonstrates major interindividual variability. Classic anatomical textbooks, including Netter’s Atlas of Human Anatomy and Sobotta’s Atlas, depict a standard branching pattern for the SMA in which the ileocolic artery (ICA), right colic artery (RCA), and middle colic artery (MCA) arise sequentially. Both arterial and venous configurations deviate substantially from this simplified model, particularly regarding the presence, origin, and branching of the right colic vessels and the configuration of Henle’s gastrocolic venous trunk (Fig. 1)^[5,6^].

Figure 1.

Schematic illustration of the superior mesenteric artery (SMA) and its right colonic branches.

The gastrocolic trunk (GT) of Henle, first described by Johann Georg Henle in 1868, represents a common venous confluence typically formed by the right gastroepiploic vein (RGEV) and the right colic vein (RCV) before draining into the anterior aspect of the SMV. Its prevalence, however, varies from 43% to 100% in published series, and at least four distinct tributary configurations have been identified^[5,7^]. Failure to anticipate these venous variants may lead to avulsion injury of the SMV during central dissection, with potentially catastrophic hemorrhagic consequences.

Detailed preoperative vascular mapping using multidetector CT angiography and three-dimensional (3D) reconstruction has therefore gained increasing importance for operative planning and surgical standardization in right colon cancer surgery^[8,9^]. This is especially relevant during laparoscopic and robotic approaches, where tactile feedback is limited.

The present study aimed to systematically evaluate mesenteric vascular variations in patients undergoing CME/D2 right hemicolectomy for right colon cancer, to classify Henle’s trunk configurations encountered, to compare findings with the published literature, and to analyze the clinical implications for operative safety and oncologic quality in a tertiary referral center.

Materials and methods

Study design and setting

A retrospective descriptive single-center study was conducted at a tertiary referral university hospital. The study was reported in accordance with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Ethical approval was obtained from the institutional review board (reference available upon request), and the study was conducted in accordance with the Declaration of Helsinki.

Study population

All consecutive patients who underwent oncologic right hemicolectomy with CME and D2 lymphadenectomy for histologically confirmed right colon adenocarcinoma between January 2020 and January 2025 were included. Inclusion criteria comprised: (i) histologically proven adenocarcinoma of the cecum, ascending colon, hepatic flexure, or right two-thirds of the transverse colon; (ii) surgical resection with curative or potentially curative intent; and (iii) complete operative and pathological records. Exclusion criteria were incomplete medical records, palliative procedures, recurrent tumors, a synchronous or metachronous second malignancy requiring major modification of the operative approach, or unavailable imaging data precluding vascular assessment.

HIGHLIGHTS

• Mesenteric vascular anatomy showed substantial interindividual variability during right colon cancer surgery, with the right colic artery absent in 35.2% of cases.

• Henle’s gastrocolic trunk was identified in 59.2% of patients (n = 148/250), and three distinct venous configurations were described and classified.

• Preoperative CT angiography enabled detailed characterization of mesenteric vascular anatomy and was used to assist operative planning in elective cases.

• Adequate lymph node harvest (≥12 nodes) was achieved in 100% of patients, with a mean yield of 24.6 ± 6.8 nodes.

• Standardized vascular-oriented CME/D2 dissection was associated with no major intraoperative vascular injuries despite extensive lymphadenectomy.

Data collection

Clinical, radiological, operative, pathological, and postoperative data were retrospectively extracted from electronic medical records, anesthesia charts, and operative reports by two independent reviewers. Discrepancies were resolved by consensus with a senior surgeon. Patient demographics, comorbidities, presenting symptoms, ASA classification, preoperative imaging modalities, operative technique, pathological staging (TNM, 8th edition), lymph node harvest, and postoperative outcomes (classified according to the Clavien–Dindo grading system) were recorded.

Radiological evaluation and CT angiography

All patients underwent contrast-enhanced thoraco-abdominopelvic CT as part of preoperative oncologic staging. CT angiography with dedicated vascular reconstruction [maximum intensity projection (MIP) and 3D volume rendering] was performed when available to evaluate: (i) SMA branching pattern; (ii) ICA anatomy and origin; (iii) RCA variability (presence, origin, and course); (iv) MCA anatomy; (v) Henle’s trunk configuration and tributary drainage; and (vi) SMV branching pattern.

CT angiography was not systematically performed in all patients. Incomplete use was attributable to the following principal reasons, documented retrospectively from clinical records: emergency or complicated presentations requiring urgent surgery without delay for dedicated vascular imaging (50 patients, 41.0% of the 122 non-CTA patients, corresponding to 64.1% of the 78 patients with a complicated presentation), limited availability of specialized vascular CT angiography software or institutional protocol constraints at the time of treatment (42 patients, 34.4%), and adequacy of standard CT for operative planning in straightforward anatomical configurations (30 patients, 24.6%). Radiological findings were correlated with intraoperative observations in all cases. In patients without preoperative CT angiography, mesenteric arterial and venous anatomy was determined exclusively by direct intraoperative visualization, documented in the operative report by the operating surgeon and subsequently reviewed by two independent investigators for classification purposes, with discrepancies resolved by consensus. A structure was classified as truly absent only when its absence was explicitly and unambiguously documented; cases with ambiguous or missing documentation were excluded from the corresponding anatomical variable rather than classified as absent. When CT angiography and intraoperative findings were both available but discordant, the intraoperative finding was considered the reference standard given its direct anatomical visualization; a formal concordance analysis between the two methods was not performed and is acknowledged as a limitation.

Surgical technique

All patients underwent oncologic right hemicolectomy with CME and D2 lymphadenectomy according to standardized oncologic principles. The medial-to-lateral approach was favored for elective cases. The mesocolic plane was developed along the embryological fusion fascia of Fredet, and central vascular ligation was performed at the origin of the ileocolic vessels from the SMA/SMV, the right branch of the middle colic vessels, and the right colic vessels, when present. Henle’s trunk dissection was performed under direct vision with identification of individual tributaries prior to ligation (Fig. 2). Lymph node dissection along the SMA was carried out to the level of the ileal branches inferiorly and the inferior pancreaticoduodenal vessels superiorly. The operative approach (open or laparoscopic) was determined by the surgeon’s expertise, presentation context, and patient characteristics.

Figure 2.

Standardized “Henle-first” cranio-caudal approach during complete mesocolic excision (CME) with D2 lymphadenectomy for right colon cancer. (A) Division of the gastrocolic ligament along the lateral border of the gastroepiploic arcade. (B) Identification and dissection of the right gastroepiploic vein (RGEV). (C) Exposure of the superior right colic vein (SRCV) along the RGEV. (D) Marking of the planned dissection line according to the projection of the superior mesenteric vein (SMV). (E) Entry into the infraduodenal fusion plane. (F) Exposure and skeletonization of the SMV and the superior mesenteric artery (SMA) and their branches. (G) Cranial dissection along the left border of the SMV with identification of the right branch of the middle colic artery (MCA). (H) Ligation and division of the right branch of the MCA, followed by division of the middle colic vein (MCV). (I) Completion of central D2 lymphadenectomy.

RGEV, right gastroepiploic vein; SRCV, superior right colic vein; SMV, superior mesenteric vein; SMA, superior mesenteric artery; MCA, middle colic artery; MCV, middle colic vein.

Statistical analysis

Continuous variables are presented as means ± standard deviations (SDs) with ranges. Categorical variables are expressed as absolute numbers and percentages. Given the descriptive nature of the study, no comparative inferential statistics were pre-specified; however, frequency distributions of vascular configurations are presented and compared with published reference series.

Results

Patient characteristics

A total of 250 consecutive patients were included over the 5-year study period. Detailed baseline patient characteristics are presented in Table 1. The mean age was 64.5 ± 11.2 years (range 28–89). Females constituted 55.2% of the cohort. More than half of the patients were aged 65 years or older (54.4%). Comorbidities were frequent, with hypertension in 39.2% and diabetes mellitus in 24.8% of patients. ASA III–IV status was recorded in 28.0% of cases.

Table 1.

Baseline patient characteristics (n = 250).

Variable	n/Mean ± SD	%/Range
Age (years)	64.5 ± 11.2	28–89
≥65 years	136	54.4%
<65 years	114	45.6%
Sex
Female	138	55.2%
Male	112	44.8%
BMI (kg/m2)	26.1 ± 4.3	17.4–38.2
ASA score
ASA I	38	15.2%
ASA II	142	56.8%
ASA III	62	24.8%
ASA IV	8	3.2%
Presenting symptoms
Anemia/occult bleeding	118	47.2%
Abdominal pain	102	40.8%
Palpable mass	44	17.6%
Weight loss	61	24.4%
Complicated presentation	78	31.2%
Acute obstruction	41	16.4%
Perforation	22	8.8%
Hemorrhage	15	6.0%
Comorbidities
Hypertension	98	39.2%
Diabetes mellitus	62	24.8%
Cardiovascular disease	44	17.6%
Chronic kidney disease	18	7.2%
COPD	24	9.6%

RGEV, right gastroepiploic vein; RCV, right colic vein; ASA, American Society of Anesthesiologists.

The most common presenting symptoms were anemia or occult bleeding (47.2%) and abdominal pain (40.8%). Complicated presentations, including acute obstruction (16.4%), perforation (8.8%), and hemorrhage (6.0%), accounted for 31.2% of cases, reflecting the predominantly symptomatic patient population at our tertiary referral center.

Radiological findings and CT angiography

All 250 patients underwent contrast-enhanced thoraco-abdominopelvic CT for preoperative staging. CT angiography with dedicated vascular reconstruction was performed in 128 patients (51.2%). The remaining 122 patients (48.8%) were evaluated with standard CT only; the reasons for this incomplete use are detailed in Table 2 and in the Methods section. Tumor characteristics and preoperative staging data are summarized in Table 2.

Table 2.

Radiological findings and preoperative staging (n = 250).

Radiological parameter	n	%
CT angiography performed	128	51.2%
CT angio not performed (standard CT only)	122	48.8%
Reason for incomplete CT angiography use
Emergency/complicated presentation	50	41.0% of the 122 patients without CTA (equivalently 64.1% of the 78 patients with complicated presentation)
Resource/protocol constraints	42	34.4% of the 122 patients without CTA
Adequate standard CT for planning	30	24.6% of the 122 patients without CTA
Tumor location
Cecum	82	32.8%
Ascending colon	98	39.2%
Hepatic flexure	45	18.0%
Transverse (right two-thirds)	25	10.0%
T stage (TNM 8th edition)
T2	22	8.8%
T3	148	59.2%
T4a	52	20.8%
T4b	28	11.2%
N stage
N0	150	60.0%
N1	62	24.8%
N2	38	15.2%

Vascular anatomical variations

Detailed vascular anatomical findings, confirmed by CT angiography and/or intraoperative observation, are presented in Table 3.

Table 3.

Vascular anatomical variations arterial and venous findings (n = 250).

Vascular structure/variant	n	%	CT angio confirmed (n = 128)
Arterial anatomy
Ileocolic artery (ICA) present	250	100%	128/128 (100%)
ICA origin from SMA right aspect	218	87.2%	110/128
ICA origin from SMA anterior aspect	32	12.8%	18/128
Middle colic artery (MCA) present	250	100%	128/128 (100%)
Classic bifurcation (right + left branch)	198	79.2%	102/128
Trifurcation pattern	32	12.8%	17/128
Single dominant branch	20	8.0%	9/128
Right colic artery (RCA) present	162	64.8%	84/128
RCA absent/replaced by ICA branch	88	35.2%	44/128
RCA from SMA	118	72.8% of RCA +	60/84
RCA from MCA	30	18.5% of RCA +	16/84
RCA from ICA	14	8.6% of RCA +	8/84
Venous anatomy and Henle’s trunk
Henle’s trunk (GT) identified	148	59.2%	78/128
Henle’s trunk absent/no common trunk	102	40.8%	50/128
Henle’s trunk configurations (n = 148)
Classic: RGEV + RCV → SMV	88	59.5%	46/78
RGEV + RCV + ARCV → SMV (3 tributaries)	42	28.4%	22/78
RGEV + RCV + MCV → SMV	18	12.2%	10/78
SMV direct tributary drainage (no GT)	102	40.8%	50/128
RCV direct to SMV	54	52.9% of no-GT	28/50
RGEV direct to SMV	34	47.1% of no-GT	22/50

Arterial anatomy

The ICA was identified as a constant finding in all 250 patients (100%), arising most frequently from the right lateral aspect of the SMA (87.2%) or, less commonly, from its anterior aspect (12.8%). The MCA was similarly constant (100%), with a classic bifurcation into right and left branches in 79.2% of cases; trifurcation was noted in 12.8% of cases, and a single dominant branch in 8.0% of cases.

The RCA was the most variable structure (Fig. 3), being absent or replaced by a branch of the ICA in 35.2% of patients. When present (n = 162, 64.8%), the RCA originated from the SMA in 72.8%, from the MCA in 18.5%, and from the ICA in 8.6% of cases. These findings confirm the major anatomical variability of the right colic pedicle, which has direct implications for the extent of central ligation and the risk of inadvertent injury during D2 lymphadenectomy.

Figure 3.

Coronal contrast-enhanced abdominal CT with MIP reconstruction demonstrating the branching pattern of the superior mesenteric artery (SMA; yellow arrow), which gives rise to the right colic artery from its anterior aspect (blue arrow) and to the ileocolic artery from its right-lateral aspect (red arrow), with a curved distal course showing left-sided concavity.

Venous anatomy and Henle’s GT

Henle’s GT was identified in 148 patients (Fig. 4; 59.2%). Three distinct venous drainage configurations were encountered and classified (Table 3):

• Type 1 (classic): Confluence of the right gastroepiploic vein (RGEV) and RCV, forming a common trunk before draining into the anterior aspect of the SMV, was identified in 54.3% of Henle’s trunk cases (88/148).

• Type 2 (three-tributary): a common trunk formed by the RGEV, the RCV, and the anterior right colic vein (ARCV), identified in 25.9% (42/148).

• Type 3 (RGEV + RCV + MCV): The junction of the RGEV, RCV, and middle colic vein (MCV) was identified in 11.1% (18/148).

Figure 4.

Coronal contrast-enhanced abdominal CT with MIP reconstruction showing the superior mesenteric vein (SMV, yellow arrow) receiving Henle’s gastrocolic trunk (green arrow), itself formed by the confluence of the right colic vein (red arrow) and right gastroepiploic vein (white arrow), a Type 1 (classic) configuration.

An additional anatomical pattern consisted of independent drainage of the RGEV and RCV directly into the SMV, without formation of a common venous trunk. This configuration was classified as absence of a common trunk rather than as a Henle’s trunk variant.

In the remaining 102 patients (40.8%), no common venous trunk was identified (Fig. 5); the RGEV and RCV drained individually and directly into the SMV (52.9% and 47.1% of this subgroup, respectively).

Figure 5.

Coronal contrast-enhanced abdominal CT with MIP reconstruction showing the SMV (yellow arrow) separately receiving the right colic vein (blue arrow) and the right gastroepiploic vein (green arrow) without a common trunk, corresponding to the absence of Henle’s trunk.

GT, gastrocolic trunk; SMA, superior mesenteric artery; SMV, superior mesenteric vein; ICA, ileocolic artery; RCA, right colic artery; MCA, middle colic artery; RGEV, right gastroepiploic vein; RCV, right colic vein; ARCV, anterior right colic vein; MCV, middle colic vein.

Operative data

Operative characteristics are summarized in Table 4. Open surgery was performed in 168 patients (67.2%), laparoscopic resection was performed in 74 patients (29.6%), and 8 cases (3.2%) required conversion from laparoscopic to open. The mean operative time was 168 ± 42 minutes overall (open: 155 ± 36 minutes; laparoscopic: 196 ± 48 minutes). Intraoperative blood loss averaged 182 ± 94 mL, with transfusion required in 28 patients (11.2%).

Table 4.

Operative data (n = 250).

Operative parameter	n/Mean ± SD	%/Range
Surgical approach
Open right hemicolectomy	168	67.2%
Laparoscopic right hemicolectomy	74	29.6%
Laparoscopic converted to open	8	3.2%
Anastomosis type
Ileocolic hand-sewn	112	44.8%
Ileocolic stapled	138	55.2%
Operative time (min)	168 ± 42	90–310
Open	155 ± 36	90–245
Laparoscopic	196 ± 48	130–310
Intraoperative blood loss (mL)	182 ± 94	50–950
Blood transfusion required	28	11.2%
Intraoperative vascular injury (major)	0	0%
Intraoperative vascular injury (minor)	12	4.8%
Managed conservatively (suture/clip)	12	100% of minor
CME plane achieved (mesofascial/mesorectal)	238	95.2%
D2 lymphadenectomy completed	238	95.2%
Preoperative CT angiography used for planning	128	51.2%

No major intraoperative vascular injury (requiring vascular repair or causing hemodynamic instability) was recorded. Twelve patients (4.8%) experienced minor venous bleeding during SMV or Henle’s trunk dissection, and all were managed conservatively with direct suture or clip application, without requiring conversion or transfusion in this subgroup. CME in the mesocolic plane was achieved in 95.2% of cases; D2 lymphadenectomy with central vascular ligation, as strictly defined, was completed in 238 patients (95.2%). The remaining 12 patients (4.8%) underwent lymphadenectomy with an intermediate-level vascular ligation not meeting central D2 criteria, most often related to unfavorable mesenteric vascular anatomy encountered during dissection (Figs 6 and 7).

Figure 6.

Intraoperative view showing central ligation: the root of the ileocolic vein (1), the corresponding ileocolic artery, coursing beneath it, already divided (2), after complete exposure of the superior mesenteric vein (3), and superior mesenteric artery (4), which are covered by the autonomic nerve plexus.

Figure 7.

Representative configurations of Henle’s gastrocolic trunk identified on CT angiography and confirmed intraoperatively, corresponding to the three types described in Table 3.

Pathological outcomes

Pathological results are detailed in Table 5. Adequate lymph node harvest (≥12 nodes) was achieved in all 250 patients. The mean number of nodes retrieved was 24.6 ± 6.8 (range 12–58), and ≥20 nodes were obtained in 77.6% of cases. Lymph node metastases were identified in 100 patients (40.0%). R0 resection was achieved in 96.8% of cases. Mesocolic plane quality assessment revealed mesocolic-plane excision in 72.8% of cases, intramesocolic in 22.4%, and muscularis propria plane in 4.8%.

Table 5.

Pathological outcomes (n = 250).

Pathological parameter	n/Mean ± SD	%/Range
Total lymph nodes harvested	24.6 ± 6.8	12–58
≥12 nodes (adequate harvest)	250	100%
≥20 nodes	194	77.6%
Lymph node metastases	100	40.0%
Pathological staging (pTNM)
Stage I (pT1-2 N0)	34	13.6%
Stage II (pT3-4 N0)	116	46.4%
Stage III (any T N1-2)	88	35.2%
Stage IV (M1, synchronous)	12	4.8%
Resection margin status
R0 (margin ≥1 mm)	242	96.8%
R1 (margin <1 mm)	8	3.2%
Mesocolic plane quality (Quirke score)
Mesocolic plane	182	72.8%
Intramesocolic plane	56	22.4%
Muscularis propria plane	12	4.8%
Vascular pedicle ligation level
Central (D2 at SMA/SMV origin)	238	95.2%
Intermediate	12	4.8%
Tumor differentiation
Well differentiated (G1)	38	15.2%
Moderately differentiated (G2)	164	65.6%
Poorly differentiated (G3)	48	19.2%

Postoperative outcomes and follow-up (Fig. 8)

Figure 8.

Intraoperative image demonstrating metastatic lymph node involvement at the root of the gastrocolic trunk of Henle, highlighting the oncologic importance of systematic central venous dissection during D2 lymphadenectomy.

Postoperative data and follow-up findings are presented in Table 6. Overall, 30-day postoperative morbidity was 27.2%, predominantly Clavien–Dindo Grade I–II (20.8%). Major complications (Grade III–IV) occurred in 14 patients (5.6%). The 30-day mortality rate was 0.8% (2 patients). Anastomotic leakage was observed in 6 cases (2.4%). The mean hospital stay was 9.2 ± 4.8 days (open: 10.4 ± 5.1; laparoscopic: 6.8 ± 2.6). No major postoperative vascular complications were recorded. Oncologic recurrence outcomes were not analyzed in the present series, as standardized follow-up protocols (a final follow-up date, systematic tracking of loss-to-follow-up, and a predefined method of recurrence assessment) were not consistently applied across the retrospective study period; this is acknowledged as a limitation below.

Table 6.

Postoperative outcomes and follow-up (n = 250).

Postoperative outcome	n/Days ± SD	%/Range
Hospital stay (days)	9.2 ± 4.8	4–42
Open	10.4 ± 5.1	5–42
Laparoscopic	6.8 ± 2.6	4–18
Overall postoperative morbidity (≤30 d)	68	27.2%
Clavien–Dindo classification
Grade I	28	11.2%
Grade II	24	9.6%
Grade IIIa	8	3.2%
Grade IIIb	4	1.6%
Grade IV	2	0.8%
Grade V (death ≤30 d)	2	0.8%
Specific complications
Anastomotic leak	6	2.4%
Surgical site infection (SSI)	22	8.8%
Ileus/delayed gastric emptying	18	7.2%
Intraabdominal abscess	8	3.2%
Postoperative hemorrhage	4	1.6%
Urinary tract complications	10	4.0%
Reoperation rate (≤30 d)	8	3.2%
30-day mortality	2	0.8%
Follow-up (months)	28.4 ± 12.6	6–60
Adjuvant chemotherapy administered	82	32.8%

Discussion

The present study systematically evaluated mesenteric vascular variations in 250 patients undergoing CME/D2 right hemicolectomy, providing retrospectively collected anatomical and outcome data from a tertiary referral center. Taken together, our findings strongly support the concept that mesenteric vascular variability should be regarded as the rule, not the exception in right colon cancer surgery.

Arterial variability: right colic artery and SMA branching (Fig. 9)

Figure 9.

Variations in the branching pattern of the superior mesenteric artery (SMA) and the anatomical relationship of the ileocolic artery (ICA) and right colic artery (RCA) to the superior mesenteric vein (SMV), according to the classification reported by Cirocchi et al (2021).

RGEV, right gastroepiploic vein; ASPDV, anterior superior pancreaticoduodenal vein; SRCV, superior right colic vein; RCV, right colic vein; MCV, middle colic vein; ICV, ileocolic vein; SMV, superior mesenteric vein.

The ICA and MCA were constant findings in our entire series, consistent with well-established anatomical references (Netter’s Atlas and Sobotta’s Atlas) and prior surgical studies^[10,11^]. In contrast, the RCA demonstrated significant variability, being absent or incorporated into the ICA branching pattern in 35.2% of patients. This figure aligns closely with the systematic review of Negoi et al^[12^], which reported RCA absence in 13–74% of cases across published series (pooled estimate: approximately 35%). The heterogeneous origin of the RCA from the SMA (72.8%), MCA (18.5%), or ICA (8.6%) in our series has been well documented by Ignjatovic et al^[10^] and Wu et al^[11^], and represents a key anatomical consideration during central ligation, since inadvertent division of a dominant RCA arising from the MCA may compromise the vascular supply to the proximal transverse colon.

The variability of SMA branching underscores the value of individualized preoperative vascular mapping. In patients undergoing CT angiography in our series, the precise identification of the RCA origin enabled targeted central ligation and informed intraoperative decision-making, particularly in cases of trifurcation or aberrant MCA branching.

Henle’s GT: prevalence, classification, and comparison with the literature (Fig. 10)

Figure 10.

Anatomical classification and morphometric characteristics of Henle’s gastrocolic trunk, illustrating the main venous drainage patterns and their relationship to the superior mesenteric vein (SMV), adapted from Negoï et al (Scientific Reports, 2018).

RGEV, right gastroepiploic vein; ASPDV, anterior superior pancreaticoduodenal vein; SRCV, superior right colic vein; RCV, right colic vein; MCV, middle colic vein; ICV, ileocolic vein; SMV, superior mesenteric vein.

Henle’s trunk was identified in 59.2% of our patients, which is lower than the pooled prevalence of 77.5% reported in the systematic review and meta-analysis by Stefura et al^[7^] and the 78% prevalence reported in the cadaveric study by Yamaguchi et al^[5^]. Our comparatively lower prevalence may reflect the inclusion of emergency cases and partial reliance on intraoperative assessment (rather than systematic CT angiography) for venous anatomy classification.

Importantly, we identified and classified three distinct tributary configurations of Henle’s trunk (Table 3), which align with the classification systems proposed by Yamaguchi et al^[5^] and the review of Peltrini et al^[6^]. The most common type in our series, the classic RGEV + RCV confluence (Type 1, 54.3%), is consistent with previously published data. The presence of a third tributary (Types 2 and 3, comprising 40.5% of Henle’s trunk cases) has particular surgical relevance: unexpected ligation of the ARCV or MCV during GT division may lead to venous ischemia of the anastomotic segment, while inadvertent avulsion may precipitate SMV hemorrhage.

Table 7 provides a direct comparison of Henle’s trunk prevalence and configuration data between our series and major published reference studies.

Table 7.

Comparison of Henle’s gastrocolic trunk prevalence with published literature.

Study	n	GT prevalence	Classic type (%)	Main variants reported
Yamaguchi et al, 2002 (cadaver)[5]	58	78.0%	~55%	2–4 tributary configs
Peltrini et al, 2019 (review)[6]	–	70–100%	Variable	Multiple classification systems
Stefura et al, 2018 (meta-analysis)[7]	–	77.5%	~60%	RCV ± ARCV ± MCV variants
Wu et al, 2019 (laparoscopic)[11]	126	68.3%	52.3%	Right gastroepiploic dominant
Present study (2025)	250	59.2%	59.5%	3 distinct configurations (see Table 3)

CT angiography: Value, limitations, and incomplete use

CT angiography with 3D vascular reconstruction was performed in 128 of 250 patients (51.2%). The incomplete use of CTA is a recognized limitation of this retrospective study and warrants specific comment, as highlighted by the reviewers. Three principal reasons accounted for the absence of CT angiography in the remaining 48.8% of patients. First, and most importantly, 50 of the 122 non-CTA patients (41.0%; equivalent to 64.1% of the 78 patients with a complicated presentation) required urgent or emergency surgery, precluding the organizational delay necessary to obtain dedicated CT angiography. Second, 42 patients (34.4%) were treated early in the study period or under local resource or protocol constraints, before systematic vascular mapping was introduced as an institutional standard. Third, in 30 patients (24.6%), the operating surgeon judged standard CT to provide sufficient anatomical delineation for operative planning.

Despite this limitation, CT angiography provided decisive anatomical information in a substantial proportion of cases, notably in identifying aberrant RCA origins, anticipating multi-tributary Henle’s trunk configurations, and guiding safe medial-to-lateral dissection planes. These observations remain descriptive and hypothesis-generating; no formal comparative analysis adjusting for potential confounders (e.g., case complexity, emergency settings) was performed, and the apparent association between CT angiography and reduced vascular risk should not be interpreted as a demonstrated causal or protective effect. The implementation of systematic preoperative CT angiography in all elective right hemicolectomies is now our institutional standard, and the current series will serve as a baseline for prospective evaluation. Several randomized and non-randomized studies have confirmed the value of preoperative mesenteric vascular mapping in reducing operative time, improving orientation during laparoscopic CME, and reducing the risk of vascular injury^[8,9,12^].

Oncologic and safety outcomes

The oncologic quality of the resection in our series was satisfactory by international standards. Adequate lymph node harvest (≥12 nodes) was achieved in all patients, with a mean yield of 24.6 ± 6.8 nodes, comparing favorably with the ≥12-node threshold recommended by current guidelines^[13^]. R0 resection was achieved in 96.8% of cases. Mesocolic-plane excision was documented in 72.8% of patients, a rate that, while lower than the rates reported in specialized CME centers in Europe^[14,15,16^]reflects the challenging case mix at our institution, including a high proportion of emergency and T4 presentations.

Crucially, no major intraoperative vascular injury was recorded, despite the high prevalence of complex venous anatomy. Most minor venous bleeding episodes occurred during SMV dissection in patients without preoperative CT angiography. Because no adjusted comparative analysis was performed, this observation should be considered descriptive and hypothesis-generating rather than evidence of a protective effect. This finding is consistent with the concept advanced by Bertelsen et al^[14^] and Kobayashi et al^[15^] that standardized vascular-oriented surgery, combined with surgeon experience and careful anatomical preparation, can achieve both oncologic quality and operative safety.

What is new in this study?

Several observations in this series add to the existing literature. First, this is, to our knowledge, one of the few reported series from the North Africa/Middle East (MENA) region to characterize mesenteric vascular anatomy during CME/D2 right hemicolectomy, providing regionally specific anatomical data that may differ from European cadaveric or Japanese surgical series owing to population-level anatomical variation. Second, we systematically classified three Henle’s trunk configurations in a clinical operative series, correlating CT angiography findings with intraoperative anatomy, which has rarely been reported with this level of detail outside specialized Japanese and European centers. Third, we document the surgical consequences of vascular variation (minor bleeding events) and their descriptive association with the absence of preoperative CT angiography. These observations support the rationale for prospective evaluation of dedicated vascular mapping, but should not be interpreted as evidence of a protective effect.

Limitations

The principal limitations of this study include its retrospective and single-center design, the incomplete use of CT angiography in approximately half of the patients (addressed above), the absence of a control group or randomization, and the relatively limited laparoscopic case volume. The retrospective design may have introduced information bias in anatomical assessment and complication recording. Additionally, the Quirke mesocolic-plane quality assessment was performed retrospectively based on pathological reports rather than by a dedicated pathologist blinded to clinical data, which may underestimate the true rate of mesocolic-plane excision. Furthermore, mesenteric anatomical findings were pooled across three assessment modalities with differing sensitivity for small arterial and venous branches (CT angiography, standard CT, and intraoperative observation); the reported prevalence estimates should therefore be regarded as an aggregate clinical-series estimate rather than a method-standardized prevalence, and direct comparison with studies relying on systematic CT angiography or cadaveric dissection should be made with caution. Finally, oncologic recurrence outcomes could not be reliably analyzed given incomplete standardization of follow-up documentation across the study period, and are not reported in this revised version. These limitations are consistent with a descriptive retrospective cohort study and are acknowledged in the interpretation of the results.

Conclusion

The mesenteric vascular anatomy shows major and clinically relevant variability during right colon cancer surgery, particularly regarding the right colic pedicle and Henle’s gastrocolic venous trunk. These variations should be considered common anatomical patterns rather than exceptional findings. Three distinct configurations of Henle’s trunk have been identified in the present series and are consistent with established anatomical classifications. Preoperative CT angiography with vascular reconstruction appears to be a valuable tool for operative planning and anatomical orientation during CME/D2 lymphadenectomy, particularly in elective cases. A standardized, vascular-oriented right hemicolectomy may improve oncologic quality and reduce the risk of major vascular complications. Prospective multicenter studies with systematic vascular mapping and standardized pathological quality assessment are warranted to further define the oncologic impact of anatomical variability on CME outcomes.

Ethical approval

The study was conducted in accordance with the Declaration of Helsinki. Patient anonymity and confidentiality were respected throughout data collection and analysis.

Consent

Written informed consent for anonymized, retrospective data use was obtained from all patients whenever required by institutional policy.

Sources of funding

The authors received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Author contributions

Conceptualization: T.D., A.D., and R.A.; Data collection: T.D., A.D., and R.A.; Methodology: T.D., A.D., and R.A.; Formal analysis: T.D., A.D., and R.A.; Writing – original draft: T.D.; Writing – review and editing: T.D., H.Z., S.N., I.S., A.G., R.J., and M.B.

Conflicts of interest disclosure

The authors declare that they have no competing interests related to this work.

Research registration unique identifying number (UIN)

Not applicable.

Guarantor

Tarik Deflaoui.

Provenance and peer review

Not commissioned; externally peer reviewed.

Data availability statement

All data generated or analyzed during this study are included in this published article.

Additional information is available from the corresponding author upon reasonable request.