CT and operative images for evaluation of right colectomy with extended D3 mesenterectomy anterior and posterior to the mesenteric vessels

Background Surgical techniques like complete mesocolic excision (CME) and D3 mesenterectomy, D3 refering to the N3 lymph node groups central in the mesentery removed at surgery, were introduced without proper evaluation of the lymphadenectomy. The aim of this study was to measure the vascular stumps and evaluate the extent and quality of lymphadenectomy after right colectomy with extended D3 mesenterectomy anterior/posterior to the mesenteric vessels. We also compared the investigation methods. Methods Residual vascular stumps were measured using three-dimensional (3D) reconstructed anatomy from follow-up computed tomography (CT) datasets and images taken during surgery. The quality of central lymphadenectomy was evaluated on the images. Results In total, 31 patients (15 females), median age 67 years (50–78), with stage I (n=7), stage II (n= 13), and stage III (n= 11) disease, were operated. Tumor locations were: 14 (45%) in the cecum, ten (32%) in the ascending colon, three (10%) in the hepatic flexure, and four (13%) in the transverse colon. The middle colic artery (MCA) was divided at its origin (13 patients) or its right branch (18 patients). Median lengths (range) of residual vascular stumps measured on 3D reconstructed CT and photographic images taken during surgery were: right colic artery: 0.0 mm (0.0–1.8)/0.0 mm (0.0–1.1), ileocolic artery: 0.0 mm (0.0–7.2)/0.0 mm (0.0–3.0), ileocolic vein: 0.0 mm (0.0–7.5)/0.0 mm (0.0–0.0), MCA: 0.0 mm (0.0–18.1)/1.0 mm (0.0–8.0), and right branch of the MCA: 0.0 mm (0.0–1.8)/0.0 mm (0.0–2.0). There was no significant difference between average lengths measured with the two techniques. The extent of lymphadenectomy was deemed acceptable in all patients. No differences in stump lengths were found in patients with different vascular crossing patterns in the central mesentery and presumably different degree of difficulty at surgery. Conclusion The results demonstrate very short residual vascular stumps and together with operative photographs provide objective evidence for superior lymphadenectomy in right colectomy with extended D3 mesenterectomy

Navigating the mesentery: part II. Vascular abnormalities and a review of the literature

Aim Vascular abnormalities present advantages and/or disadvantages for the patient undergoing surgery. The aims of this study were to define, classify and demonstrate the courses, and to assess the clinical value, of arterial and venous abnormalities in the central mesentery. Method We conducted a review of the anatomy of 340 patients planned for enrolment in the ‘Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic MDCT Angiography' trial, 312 of whom were submitted to surgery. Vascular abnormalities were analysed in context with surgical notes and images. A metaanalysis of the literature was performed. Results Arterial Abnormalities were found in 28 (8.2%) of the 340 patients and were classified into the following three groups based on anticipated surgical difficulty: group 1, accessory or replaced arteries to solid organs [14 (4.1%)]; group 2, arterial shunts [11 (3.2%)] between the coeliac trunk and the superior mesenteric artery, which resulted in bleeding in three patients; and group 3, common stem abnormalities [3 (0.9%)]. Two groups of superior mesenteric vein abnormalities were noted. The first included morphological abnormalities in a single vein [4 (1.2%)]: aneurysm [1 (0.3%)]; and ring variants of principal tributaries [3 (0.9%)]. The second included double superior mesenteric vein trunks [31 (9.1%)]: genuine bifid [10 (2.9%)]; and pseudo bifid [21 (6.2%)]. The meta-analysis revealed 26 articles, including 10 series of anatomical dissections or angiographies [1970 cases with 205 (10.4%) arterial abnormalities] and 16 case reports, none of which described a clinical or surgical setting. Conclusion Vascular abnormalities occur frequently. Arterial abnormalities are a hazard when inadvertent injury occurs during surgery. Preoperative knowledge of a bifid superior mesenteric vein is useful

Navigating the mesentery: a comparative pre- and per-operative visualization of the vascular anatomy

Awareness of anatomy is critical for performing safe surgery within the root of the mesentery. Our aim was to investigate the anatomical relationship between the superior mesenteric artery (SMA) and vein (SMV) and their branches within a predefined D3 area of the right colon and to compare preoperatively established three-dimensional (3D) mesenteric vessel anatomy from CT with that found at surgery

Comparing 5-Year Survival Rates Before and After Re-stratification of Stage I–III Right-Sided Colon Cancer Patients by Establishing the Presence/Absence of Occult Tumor Cells and Lymph Node Metastases in the Different Levels of Surgical Dissection

Background: To establish the impact of re-stratification on the outcomes of patients (stage I-III right-sided colon cancer) based on the presence/absence of occult tumor cells (OTC) and/or metastatic lymph nodes in the different levels of surgical dissection. Methods: Consecutive patients were drawn from a multicenter prospective trial. After surgery, the surgical specimen was divided into the D1/D2 and D3 volumes before being further analyzed separately. All lymph nodes were examined with cytokeratin CAM 5.2 immunohistochemically. Lymph nodes containing metastases and OTC (micrometastases; isolated tumor cells) were identified. Re-stratification was as follows: RS1, stages I/II, no OTC in D1/D2 and D3 volumes; RS2, stages I/II, OTC in D1/D2 and/or D3; RS3, stage III, lymph node metastases in D1/D2, with/without OTC in D3; RS4, stage III, lymph node metastases in D3, with/without OTC in D3. Results: Eighty-seven patients (39 men, 68.4 + 9.9 years) were included. The standard stratified (SS) group contained the following: stages I/II (SS1) 57 patients; stage III (SS2) 30 patients. Re-stratified (RS) contained RS1 (38), RS2 (19), RS3 (24), and RS4 (6) patients. Lymph node ratio (OTC) RS2: 0.157 D1/D2; 0.035 D3 and 0.092 complete specimens. Lymph node ratio RS3: 0.113 D1/D2; complete specimen 0.056. Overall survival and disease-free survival were p = 0.875 and p = 0.049 for SS and p = 0.144 and p = 0.001 for RS groups, respectively. Conclusion: This re-stratification identifies a patient group with poor prognosis (RS4). Removing this group from SS2 eliminates all the differences in survival between RS2 and RS3 groups. The level of dissection of the affected nodes may have an impact on survival. Clinical trial: "Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic Multi-Detector Computed Tomography (MDCT) Angiography" registered at https://clinicaltrials.gov/ct2/show/NCT01351714.</p