CT assessment of right colonic arterial anatomy pre and post cancer resection - a potential marker for quality and extent of surgery?

Assessing anatomical variations of the superior mesenteric artery via three-dimensional CT angiography and laparoscopic right hemicolectomy: a retrospective observational study

OBJECTIVE

This study aimed to analyse the anatomical relationships and differences between the superior mesenteric vessels and their branches by reviewing a laparoscopic right hemicolectomy surgery video and comparing it with preoperative three-dimensional computed tomography (3D-CT) angiography and to verify the accuracy of 3D-CT vascular reconstruction techniques.

METHODS

Surgical videos and preoperative imaging data of 52 patients undergoing laparoscopic right hemicolectomy were analysed to observe and summarize the probability of occurrence and adjacency of superior mesenteric vascular branches, and the lengths of specific sites of their branches were measured using the above two methods.

RESULTS

Preoperative CT images and surgical video showed that the ileocolic artery (ICA) was present in 98.1% (51/52) and the ileocolic vein (ICV) was present in 100% (52/52), and ICA was present in 13.7% (7/51) of the ICV directly anteriorly, 13.7% (7/51) anteriorly superiorly, 3.9% (2/51) anteriorly inferiorly, 11.8% (6/51) directly posteriorly, 37.2% (19/51) post superiorly, and 19.7% (10/51) posteriorly inferiorly. In the surgical video, the probability of presence of the right colic artery (RCA) was 21.2% (11/52). On CT images, the RCA was present in 10 patients. The length of the origin of the middle colic artery (MCA) from its bifurcations was 2.33 ± 0.87 cm measured intraoperatively using a sterile isometric filament, and the length measured using 3D-CT vascular reconstruction was 2.36 ± 0.91 cm; the difference was not statistically significant (P = 0.348). The length of the MCA and ICA initiation points was 3.22 ± 0.75 cm measured intraoperatively using sterile isometric filaments and 3.36 ± 0.72 cm measured using 3D-CT vascular reconstruction, which was a statistically significant difference (P < 0.001).

CONCLUSIONS

3D-CT vascular reconstruction can accurately predict the vessels related to right hemicolectomy in most cases. It is an important method for preoperative prediction of superior mesenteric vessels, which can guide surgeons in the intraoperative vessel identification.

Surgical treatment of right colon cancer

The study aimed to perform a systematic review of the literature on surgical treatment for right colon cancer (RCC) with complete mesocolic excision (CME) and D2/D3 lymph node dissection (LND). Material and Methods. A literature review was performed for studies published between 2013 and 2023 by the online resources from the official Web sites of the societies/panels and PubMed database. Sources included guidelines, meta-analyses, randomized and nonrandomized clinical studies, guidelines by European Society of Medical Oncology, the Japanese Society for Cancer of the Colon and Rectum, and the National Comprehensive Cancer Network, Russian clinical guidelines. Results. CME significantly improved both immediate and long-term treatment results, which was confirmed by numerous meta-analyses. The extent of LND remains one of the most controversial issues in RCC. For many Asian surgeons, D3 LND is the standard procedure for the treatment of RCC, whereas the European approach is more conservative and apical lymph node dissection is not mandatory. There are also large differences in understanding the extent of D3 LND in RCC. Most surgeons understand this term as dissection of adipose tissue along the anterior and lateral surface of the superior mesenteric vein, however, there are authors who perform circular dissection along the superior mesenteric vessels, considering this extent of surgery to be the most radical. Conclusion. It is necessary to standardize methods and effective criteria for quality control of CME for RCC and LND. In this case, external independent assessment of the quality of surgical intervention is important. There is also currently a growing number of studies in which intraoperative fluorescence imaging makes it possible to better visualize the location of the apical lymph nodes and individualize LND.

Macroscopic Evaluation of Colon Cancer Resection Specimens

Colon cancer is a common disease internationally. Outcomes have not improved to the same degree as in rectal cancer, where the focus on total mesorectal excision and pathological feedback has significantly contributed to improved survival and reduced local recurrence. Colon cancer surgery shows significant variation around the world, with differences in mesocolic integrity, height of the vascular ligation and length of the bowel resected. This leads to variation in well-recognised quality measures like lymph node yield. Pathologists are able to assess all of these variables and are ideally placed to provide feedback to surgeons and the wider multidisciplinary team to improve surgical quality over time. With a move towards complete mesocolic excision with central vascular ligation to remove the primary tumour and all mechanisms of spread within an intact package, pathological feedback will be central to improving outcomes for patients with operable colon cancer. This review focusses on the key quality measures and the evidence that underpins them.

Role of preoperative CT angiography with multimodality imaging reconstruction to perform laparoscopic Complete Mesocolic Excision (CME) and Central Vascular Ligation (CVL) in right-sided colon cancer: Is it really useful? A prospective clinical study

BACKGROUND

The concept of complete mesocolic excision (CME) and central vascular ligation (CVL) in right colonic resections appears to improve the oncological outcomes. The highest rate of complications reported in the literature in patients undergoing CME is related to difficult surgical manuevers and intraoperative bleeding due to the central vascular dissection.

METHODS

We used preoperative findings obtained with the CT angiography, multiplanar reformation (MPR), maximum intesity projection (MIP) and 3D volume rendering (VR) technique to verify if this preoperative radiological assessment had significant benefits regarding the difficulty of dissection of the embryological planes, the identification of vascular structures and central lymph nodes with reduction in mean operative time, intraoperative complications and better short-term outcomes versus standard contrast enhanced CT scan. We also have administered a questionnaire to investigate the subjective responses on the degree of difficulty of the surgical procedure both by the surgical team expert in CME and by a group of young surgeons.

RESULTS

Statistical analysis showed that overall operative time was significant shorter in patients underwent to radiological assessment (224,5 min; range 160-300 versus 252,6 min; range 200-340; p-value 0.023) with a significant lower rate of intraoperative complication (2.7% versus 4.2%; p-value 0.043). No differences were reported with respect to blood loss, conversion rate, anastomotic leakage or other surgical results. Analysis of the questionnaire underlined a progressive awareness of the correspondence between the radiological imaging and the surgical field.

CONCLUSION

The possibility of identifying the characteristics and course of the vascular structures along the axis of the superior mesenteric vessels certainly increases the surgeon's knowledge of the operating field, making him more confident with surgical maneuvers and significantly reducing the duration of the operating time and intraoperative complications.

The Mesentery in Complete Mesocolic Excision

The following article summarizes technical aspects of how to operate in the mesentery during complete mesocolic excision (CME). Increasingly, CME is being adopted and as such it is important to establish the anatomical basis of the techniques involved. This review thus serves to provide that foundation and explains the surgical techniques built on it.

The impact of three-dimensional reconstruction and standardised CT interpretation (AMIGO) on the anatomical understanding of mesenteric vascular anatomy for planning complete mesocolic excision surgery: A randomised crossover study

BACKGROUND

Preoperative planning is a crucial aspect of safe complete mesocolic excision (CME) surgery. 3D models derived from imaging may help improve anatomical understanding of the complex vascular anatomy. Here, we assessed the effect of 3D models on surgeons' anatomical understanding in comparison to a systematic approach for CT scan interpretation (AMIGO).

METHOD

Fifteen cases were included in the study. Two GI radiology consultants reviewed each scan to ascertain the vascular anatomy. Virtual 3D models were produced and displayed on a web-based platform (https://skfb.ly/6OZUZ). A total of 13 surgical trainees were recruited. Candidates were assessed after baseline anatomical training and subsequently using the AMIGO method and 3D models. Five cases were randomly allocated in each round of testing for each participant. The primary outcome measure was an objective vascular anatomy knowledge score. The secondary outcome measure was subjective feedback from participants.

RESULTS

Both 3D and AMIGO significantly improved anatomical understanding in comparison to baseline testing. However, 3D was superior to AMIGO (3D [n = 65; median score 8/14] vs. AMIGO [n = 65; median score 6/14; p < 0.0001]. For 13/15 patient cases examined, 3D was superior to the AMIGO method. Eleven participants demonstrated better anatomical understanding using 3D models versus AMIGO. Ten participants preferred 3D models in comparison to standard CT imaging.

CONCLUSIONS

3D models improve anatomical understanding of mesenteric vascular anatomy in a group of colorectal surgical trainees in comparison to a formal CT interpretation method. 3D models may be a useful planning adjunct to 2D imaging for CME surgery.

Postoperative Quality Assessment Score Can Select Patients with High Risk for Locoregional Recurrence in Colon Cancer

BACKGROUND

Monitoring surgical quality has been shown to reduce locoregional recurrence (LRR). We previously showed that the arterial stump length (ASL) after complete mesocolic excision (CME) is a reproducible quality instrument and correlates with the lymph-node (LN) yield. We hypothesized that generating an LRR prediction score by integrating the ASL would predict the risk of LRR after suboptimal surgery.

METHODS

502 patients with curative resections for stage I-III colon cancer were divided in two groups (CME vs. non-CME) and compared in terms of surgical data, ASL-derived parameters, pathological parameters, LRR and LRR-free survival. A prediction score was generated to stratify patients at high risk for LRR.

RESULTS

The ASL showed significantly higher values (50.77 mm ± 28.5 mm) with LRR vs. (45.59 mm ± 28.1 mm) without LRR (p < 0.001). Kaplan-Meier survival analysis showed a significant increase in LRR-free survival at 5.58 years when CME was performed (Group A: 81%), in contrast to non-CME surgery (Group B: 67.2%).

CONCLUSIONS

The prediction score placed 76.6% of patients with LRR in the high-risk category, with a strong predictive value. Patients with long vascular stumps and positive nodes could benefit from second surgery to complete the mesocolic excision.

Is Laparoscopic Complete Mesocolic Excision and Central Vascular Ligation Really Necessary for All Patients With Right-Sided Colon Cancer?

Colon cancer treatment is on the way to evolution over several decades. The minimally invasive surgery has improved postoperative short-term outcomes. Adjuvant chemotherapy has prolonged the survival of advanced colon cancer patients. Hohenberger proposed the noble concept of complete mesocolic excision (CME) which consists of 3 components: plane surgery, sufficient longitudinal bowel resection, and central vascular ligation (CVL). Mesocolic plane surgery shares the same surgical principle of total mesorectal excision, which is maintaining the intact mesothelial envelope. However, there remain debates about the extent of bowel resection and the level of CVL for maximizing lymph node dissection. There is no solid clinical evidence for the oncological necessity and benefit of extended radical dissection in right hemicolectomy. CME with CVL based on open surgery has been adopted in laparoscopic surgery. So, it is also necessary to look at how the CME could be transformed and successfully implanted in the laparoscopic era. Recent rapid advances in surgical technology and cancer biology are preparing for fundamental changes in cancer surgery. In this study, we reviewed the history, oncological necessity, and compatibility of CME for the right hemicolectomy in the laparoscopic era and outline the new perspectives on the evolution of cancer surgery.

A systematic review and meta-analysis of variants of the branches of the superior mesenteric artery: the Achilles heel of right hemicolectomy with complete mesocolic excision?

AIM

Dissection with subsequent ligation and resection of arteries at their origin (central vascular ligation) is essential for adequate oncological resection during right hemicolectomy with complete mesocolic excision. This technique is technically demanding due to the highly variable arterial pattern of the right colon. Therefore, this study aims to provide a comprehensive evidence-based assessment of the arterial vascular anatomy of the right colon.

METHODS

A thorough systematic literature search through September 2020 was conducted on the electronic databases PubMed, Scopus and Web of Science to identify studies eligible for inclusion. Data were extracted and pooled into a meta-analysis using MetaXl software.

RESULTS

A total of 41 studies (n = 4691 patients) were included. The ileocolic artery (ICA), right colic artery (RCA) and middle colic artery (MCA) were present in 99.7% (95% CI 99.4%-99.8%), 72.6% (95% CI 61.3%-82.5%) and 96.9% (95% CI 94.2%-98.8%) respectively of patients. Supernumerary RCA and MCA were observed in 3.2% and 11.4% respectively of all cases. The RCA shared a common trunk with the ICA and MCA in 13.2% and 17.7% respectively of patients. A retro-superior mesenteric vein course of the ICA and RCA was observed in 55.1% and 11.4% respectively of all cases.

CONCLUSION

The vascular anatomy of the right colon displays several notable variations, namely the absence of some branches (RCA absent in 27.4% of cases), supernumerary branches, common trunks, and retro-superior mesenteric vein courses. These variations should be taken into consideration during right hemicolectomy with complete mesocolic excision to ensure adequate oncological resection while minimizing intra-operative complications.

Routine CT evaluation of central vascular ligation in patients undergoing complete mesocolic excision for sigmoid colon cancer

AIM

Objective and reproducible quality measures of complete mesocolic excision (CME) for colon cancer are not currently available. This study aimed to measure the inferior mesenteric stump length following CME for sigmoid colon cancer and explore surgical, pathological and oncological outcomes in patients with a stump length of <10 mm vs. ≥10 mm.

METHOD

This was a single-centre, retrospective cohort study including patients undergoing minimally invasive surgery for sigmoid colon cancer between May 2013 and May 2015. Follow-up CT scans were reviewed, and a vascular stump cut-off of <10 mm for adequate central ligation of the inferior mesenteric artery was applied. Differences in perioperative, histopathological and oncological outcome parameters (overall, disease-free and recurrence-free survival) were explored between <10 mm vs. ≥10 mm groups.

RESULTS

A total of 127 patients (43% female) with a median age of 68 years were included. The median follow-up time was 68 months. CT measurements showed good interrater agreement (90% absolute agreement) and reliability among raters (kappa = 0.77, 95% CI 0.53-1.00, p < 0.001). A stump length ≥10 mm was associated with longer operating time (150 vs. 180 min, p = 0.021), intramesocolic resection (p = 0.008), and a shorter distance from the bowel wall to vascular tie (120 vs. 102 mm, p = 0.005).

CONCLUSION

An arterial stump length ≥10 mm in sigmoid resection for colon cancer was associated with key clinical quality measures. Measurement of arterial stump length using routine follow-up CT may serve as a quality indicator of vascular ligation in CME surgery.

Usefulness of three-dimensional printing of superior mesenteric vessels in right hemicolon cancer surgery

The anatomy of the superior mesenteric vessels is complex, yet important, for right-sided colorectal surgery. The usefulness of three-dimensional (3D) printing of these vessels in right hemicolon cancer surgery has rarely been reported. In this prospective clinical study, 61 patients who received laparoscopic surgery for right hemicolon cancer were preoperatively randomized into 3 groups: 3D-printing (20 patients), 3D-image (19 patients), and control (22 patients) groups. Surgery duration, bleeding volume, and number of lymph node dissections were designed to be the primary end points, whereas postoperative complications, post-operative flatus recovery time, duration of hospitalization, patient satisfaction, and medical expenses were designed to be secondary end points. To reduce the influence of including different surgeons in the study, the surgical team was divided into 2 groups based on surgical experience. The duration of surgery for the 3D-printing and 3D-image groups was significantly reduced (138.4 ± 19.5 and 154.7 ± 25.9 min vs. 177.6 ± 24.4 min, P = 0.000 and P = 0.006), while the number of lymph node dissections for the these 2 groups was significantly increased (19.1 ± 3.8 and 17.6 ± 3.9 vs. 15.8 ± 3.0, P = 0.001 and P = 0.024) compared to the control group. Meanwhile, the bleeding volume for the 3D-printing group was significantly reduced compared to the control group (75.8 ± 30.4 mL vs. 120.9 ± 39.1 mL, P = 0.000). Moreover, patients in the 3D-printing group reported increased satisfaction in terms of effective communication compared to those in the 3D-image and control groups. Medical expenses decreased by 6.74% after the use of 3D-printing technology. Our results show that 3D-printing technology could reduce the duration of surgery and total bleeding volume and increase the number of lymph node dissections. 3D-printing technology may be more helpful for novice surgeons.

Trial registration: Chinese Clinical Trial Registry, ChiCTR1800017161. Registered on 15 July 2018.

Right Colectomy with Extended D3 Mesenterectomy: Anterior and Posterior to the Mesenteric Vessels

BACKGROUND

In right colectomy for cancer, complete mesocolic excision and D3 lymphadenectomy each leave behind lymphatic tissue anterior and posterior to the superior mesenteric vein (SMV) and artery (SMA). In this article, we present D3 extended mesenterectomy: a surgical technique that excises the lymphatic tissue en bloc with the right colectomy specimen.

MATERIAL AND METHODS

A 3D map of the mesentery of the right colon was reconstructed from staging CT-angiogram scans. The surgical technique of right colectomy with D3 extended mesenterectomy consisted of eight steps: 1) reveal the SMV and SMA; 2) isolate the ileocolic artery; 3) isolate the middle colic artery; 4) resolve the anterior mesenteric flap; 5) specimen de-vascularization; 6) colectomy; 7) resolve the posterior mesenteric flap; and 8) anastomosis.

RESULTS

One-hundred-seventy-six patients (77 men) 66 years of age were operated upon from February 2011 to January 2017. There were 169 adenocarcinomas: 16.0% Stage I, 49.1% Stage II, 33.7% Stage III, 1.2% Stage IV. Tumor locations were 50.6% cecum, 41.5% ascending colon, 4.5% hepatic flexure, and 2.3% transverse colon. Mean operating time was 200 minutes, blood loss 273 ml, and length of stay 7.9 days. There were 9 anastomotic leakages and 15 reoperations. One patient underwent small bowel resection due to SMA tear. There was no postoperative mortality. The mean number of lymph nodes per specimen (40.9) was comprised of 27.1 in the D2 volume and 13.8 in the D3 volume. The mean number of metastatic lymph nodes was 1.2 in the D2 volume and 0.13 in D3. There were 7 patients with lymph node metastasis in D3, 2 of whom had node metastasis solely within D3.

CONCLUSION

This study shows that 1.2% of patients would have been incorrectly diagnosed as Stage II if extended D3 mesenterectomy had not been performed. Similarly, lymph node metastases would have been left behind in 4.1% of patients if extended D3 mesenterectomy had not been performed.

Post-operative computed tomography scan – reliable tool for quality assessment of complete mesocolic excision

BACKGROUND

Quality control in colon cancer surgery is an ongoing debate ever since standardization proved to be highly efficient in improving survival in rectal cancer. Complete mesocolic excision (CME) is widely acclaimed as the new gold-standard in colon cancer resections, thus it is imperative to establish quality criteria of CME in order to make it easily understood and verified by surgeons worldwide. One simple and reproducible tool could be the measurement of arterial stumps postoperatively and a straightforward way to test its reliability is to test it in a comparative study between CME and non-CME surgery.

AIM

To validate arterial stump measurement as a surgical quality tool by comparing CME with conventional radical colectomies.

METHODS

This was a retrospective study, carried out on a prospective database. We collected data from two groups of patients, divided according to standard CME with D2 central vascular ligation (group A) and non-standardized surgery (group B). The two groups were compared with regard to the arterial stump length after right- and left-sided colectomies for colon cancer. The actual stump lengths of the ileocolic artery (ICA) and inferior mesenteric artery (IMA) were compared with their theoretical best D2 position of predicted ligation levels (D₂PLLs) for calculating the potential for improvement. Measurements on follow-up computed tomography scans were carried out by three observers. Pathological data were recorded (specimen length, lymph node yield) and correlated with stump length.

RESULTS

We analysed 58 colectomies. The stump lengths (mean ± SD) in group A were 16.97 ± 4.77 mm for ICA and 31.70 ± 15.71 mm for IMA, whereas group B had 49.93 ± 20.29 mm for ICA and 67.24 ± 28.71 mm for IMA. Shorter lengths were obtained in group A, by a mean difference of 35.66 mm (χ² = 27.38, P < 0.001), which was significant for all types of colectomies. Except for a 5.85 ± 4.71 mm difference for right colectomies, all the ligations from group A significantly reached their potential height (0.26 ± 12.18 mm from D₂PLL; χ² = 0.005, P = 0.944). Apart from three left colectomies, group B failed to reach D₂PLL, by a mean difference of 32.14 ± 26.15 mm (χ² = 21.77, P < 0.001). The calculated improvement potentials were significantly shorter in group A than in group B, by a mean of 31.88 mm (χ²= 22.13, P < 0.001). The large spread of results in group B showed that there is significant variability (P = 0.004) when compared to standard surgery. Significant correlations were found between stump length, specimen length and number of lymph nodes (P = 0.018 and P = 0.008 respectively). No statistical difference was found between observers’ measurements (P = 0.866).

CONCLUSION

Arterial stump monitoring is a significant step in defining surgical quality, as longer stumps contain residual mesocolic tissue and correlate with major prognostic factors.

Implementation of 3D printed superior mesenteric vascular models for surgical planning and/or navigation in right colectomy with extended D3 mesenterectomy: comparison of virtual and physical models to the anatomy found at surgery

BACKGROUND

Three-dimensional (3D) printing technology has recently been well approved as an emerging technology in various fields of medical education and practice; e.g., there are numerous studies evaluating 3D printouts of solid organs. Complex surgery such as extended mesenterectomy imposes a need to analyze also the accuracy of 3D printouts of more mobile and complex structures like the diversity of vascular arborization within the central mesentery. The objective of this study was to evaluate the linear dimensional anatomy landmark differences of the superior mesenteric artery and vein between (1) 3D virtual models, (2) 3D printouts, and (3) peroperative measurements.

METHODS

The study included 22 patients from the ongoing prospective multicenter trial "Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic MDCT Angiography," with preoperative CT and peroperative measurements. The patients were operated in Norway between January 2016 and 2017. Their CT datasets underwent 3D volume rendering and segmentation, and the virtual 3D model produced was then exported for stereolithography 3D printing.

RESULTS

Four parameters were measured: distance between the origins of the ileocolic and the middle colic artery, distance between the termination of the gastrocolic trunk and the ileocolic vein, and the calibers of the middle colic and ileocolic arteries. The inter-arterial distance has proven a strong correlation between all the three modalities implied (Pearson's coefficient 0.968, 0.956, 0.779, respectively), while inter-venous distances showed a weak correlation between peroperative measurements and both virtual and physical models.

CONCLUSION

This study showed acceptable dimensional inter-arterial correlations between 3D printed models, 3D virtual models and authentic soft tissue anatomy of the central mesenteric vessels, and weaker inter-venous correlations between all the models, reflecting the highly variable nature of veins in situ.

Retromesenteric course of the middle colic artery-challenges and pitfalls in D3 right colectomy for cancer

BACKGROUND

The middle colic artery (MCA) is of crucial importance in abdominal surgery, for laparoscopic or open right and transverse colectomies. Against this background, a high number of reports concerning anatomical variations of the MCA have been published intended to contribute to the improvement of operative techniques for the treatment of colon cancer. Despite this extensive literature, briefly reviewed in the present paper, a course of the MCA posterior to the superior mesenteric vein, called a retromesenteric trajectory, has been related to only once, to the best of our knowledge.

METHODS

A total series of 507 patients included in two prospective trials concerning laparoscopic or open right colectomy for cancer between 2011 and 2017 are reported. The investigation included preoperative or postoperative multidetector-computed tomography angiography.

RESULTS

We found four (0.79%) cases of retromesenteric MCA. They all underwent meticulous image analysis with mesenteric vessels' road mapping, detailed morphometry, and surgical validation which revealed that, apart from their course, those cases did not differ significantly from the rest of the series.

CONCLUSION

This paper therefore documents the worth-knowing behavior causing considerable confusion for the operating surgeon unaware of the abnormality and shows its concrete impact on patient-tailored surgical practice, in particular for laparoscopic D3 colectomy (including the "uncinated process first" approach).

Surgical Anatomy of the Superior Mesenteric Vessels Related to Colon and Pancreatic Surgery: A Systematic Review and Meta-Analysis

The surgeon dissecting the base of the mesenterium, around the superior mesenteric vein (SMV) and artery, is facing a complex tridimensional vascular anatomy and should be aware of the anatomical variants in this area. The aim of this systematic review is to propose a standardized terminology of the superior mesenteric vessels, with impact in colon and pancreatic resections. We conducted a systematic search in PubMed/MEDLINE and Google Scholar databases up to March 2017. Forty-five studies, involving a total of 6090 specimens were included in the present meta-analysis. The pooled prevalence of the ileocolic, right colic and middle colic arteries was 99.8%, 60.1%, and 94.6%, respectively. The superior right colic vein and Henle trunk were present in 73.9%, and 89.7% of specimens, respectively. In conclusion, the infra-pancreatic anatomy of the superior mesenteric vessels is widely variable. We propose the term Henle trunk to be used for any venous confluence between gastric, pancreatic and colic veins, which drains between the inferior border of the pancreas and up to 20 mm downward on the right-anterior aspect of the SMV. The term gastrocolic trunk should not be synonymous, but a subgroup of the Henle trunk, together with to gastropancreatocolic, gastropancreatic, or colopancreatic trunk.

Radiological and pathological evaluation of the level of arterial division after colon cancer surgery

AIM

In aiming to cure patients with colorectal cancer surgery, the surgeon must carefully dissect the mesocolon and mesorectum and divide the vascular pedicle near to its origin so as to include all local lymph nodes. This has been termed complete mesocolic excision. The distance from the distal vascular tie to the bowel wall in the fixed specimen is an indication as to the quality of surgery but this does not assess the length of the residual vascular pedicle and, by implication, residual lymph nodes. The aim of this study was to establish if our surgeons were carrying out complete mesocolic excision by assessing the length of the proximal arterial pedicle and relating this to arterial length in the fixed specimen.

METHOD

This was a single centre prospective study of patients undergoing elective surgery for locally advanced colorectal cancer. An abdominal and pelvic CT scan was performed 2 days postoperatively and a radiologist blinded to the operative procedure measured the length of the residual arterial stump. Similarly, the length of the vessel in the fixed resected specimen and lymph node yield were also recorded.

RESULTS

Fifty-two patients were recruited. The mean length of the residual arterial stump was 38 mm (95% CI: 33-43), which was significantly longer than the < 10 mm recommended in guidelines (P < 0.0001). The mean length was 31 mm (95% CI: 25-37) and 49 mm (95% CI: 40-57) for left and right sided resections respectively. There was no correlation between the residual arterial stump and the pathology.

CONCLUSIONS

The residual arterial length was greater than suggested by guidelines and may indicate that our surgery is less radical than we planned. Caution should be taken when using pathological measurements of vascular ligation as it may not reflect the height of the pedicle division.

Evaluation of the vascular anatomy of the right-sided colon using three-dimensional computed tomography angiography: a single-center study of 536 patients and a review of the literature

PURPOSE

The requisite for a rigorous preoperative understanding of vascular branching continues to grow in parallel with the implementation of laparoscopic surgery. Three-dimensional (3D)-computed tomography (CT) angiography is a less-invasive modality than traditional angiographic examination. Therefore, we aimed to evaluate branching patterns of the superior mesenteric artery (SMA).

METHODS

In the present study, 536 consecutive patients who underwent preoperative 3D-CT angiography from April 2012 to March 2014 were prospectively enrolled. The branching pattern of the right colic artery (RCA) and the intersectional patterns of the RCA, ileocolic artery (ICA), and superior mesenteric vein (SMV) were evaluated.

RESULTS

The RCA existed in only 179 cases (33.4 %); the remaining 357 patients (66.6 %) lacked evidence of the RCA. The ICA was detected in all cases. The RCA ran ventral to the SMV in the majority of cases (89.4 %). Conversely, the ICA ran ventral to the SMV in only half of the cases (50.6 %). When the RCA was observed to pass dorsal to the SMV, the ICA also ran dorsal to SMV in all cases.

CONCLUSIONS

3D-CT angiography can aid surgeons in identifying and understanding the anatomical vascular variations and intersectional patterns of the RCA, ICA, and SMV. Developing awareness of these variations can aid in the prevention of unexpected vascular injury during laparoscopic right-sided colon surgery.