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

Navigating the mesentery: Part III. Unusual anatomy of ileocolic vessels

AIM

The ileocolic vessels are important landmarks in advanced surgery of the midgut. The aim of the present study is to present variations of ileocolic vessels relevant to complete mesocolic excision with D3 lymphadenectomy of the right colon, within their detailed and precise morphometric framework and deriving from a large and consistent series of operated patients.

METHODS

An ongoing prospective trial 'Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic Multidetector Computed Tomography Angiography' was reviewed. The imaging datasets underwent manual segmentation and 3D reconstruction, and the results were validated at surgery. A total of 356 patients were included in the study.

RESULTS

A cross-section of the series revealed five cases (1.4%) with variation of ileocolic vessels relevant to complete mesocolic excision or D3 extended mesenterectomy. There were two cases with absence of a true classical ileocolic artery, two cases with absence of a true classical ileocolic vein, and one case of precocious bifurcation of the ileocolic artery, left to the superior mesenteric vein. The entire D3 area in all the cases was thoroughly documented and analysed from the morphometric point of view (calibres, lengths of vessels, crossing patterns).

CONCLUSION

The preoperative visualization of a patient's individual 3D anatomy is a powerful tool in identifying the variations whose negligence could have dire consequences in complete mesocolic excision of the right colon.

Anatomical characteristics and classifications of gastrocolic trunk of Henle in laparoscopic right colectomy: preliminary results of multicenter observational study

BACKGROUND

As a key landmark during laparoscopic right colectomy, the classification and variation of the gastrocolic trunk of Henle (GTH) remains to be clarified. The aim of this nationwide multicenter study was to describe the characteristics of the GTH intra-operatively during laparoscopic right colectomies.

METHODS

Three hundred seventy-one patients who underwent laparoscopic right colectomies from January 2018 to March 2019 in 25 hospitals across China were enrolled in the study. The length of the GTH, the classification with a precise description of confluent tributaries, and other variations were analyzed.

RESULTS

Of the 371 patients, 363 had a GTH. The proportion of type-0, type-I, type-II, and type-III was 15.2% (n = 55), 54.8% (n = 199), 25.3% (n = 92), and 4.7% (n = 17), respectively. The average length of the GTH was 8.5 mm, ranging from 2 to 30 mm.

CONCLUSIONS

This is the first multicenter study with a large sample by which the GTH was classified based on laparoscopic intraoperative observation. Variations in the GTH were classified into four types based on the number of colic drainage veins (right colic, superior right colic, middle colic, accessory middle colic, and ileocolic veins), among which the right colic vein was the most common. The length of the GTH was relatively short, and thus might carry a risk of bleeding. Further clinical data should be correlated with the characteristics of the GTH.

Value of the surgeon's sightline on hologram registration and targeting in mixed reality

Purpose

Mixed reality (MR) is being evaluated as a visual tool for surgical navigation. Current literature presents unclear results on intraoperative accuracy using the Microsoft HoloLens 1^®. This study aims to assess the impact of the surgeon’s sightline in an inside-out marker-based MR navigation system for open surgery.

Methods

Surgeons at Akershus University Hospital tested this system. A custom-made phantom was used, containing 18 wire target crosses within its inner walls. A CT scan was obtained in order to segment all wire targets into a single 3D-model (hologram). An in-house software application (CTrue), developed for the Microsoft HoloLens 1, uploaded 3D-models and automatically registered the 3D-model with the phantom. Based on the surgeon’s sightline while registering and targeting (free sightline /F/or a strictly perpendicular sightline /P/), 4 scenarios were developed (FF-PF-FP-PP). Target error distance (TED) was obtained in three different working axes-(XYZ).

Results

Six surgeons (5 males, age 29–62) were enrolled. A total of 864 measurements were collected in 4 scenarios, twice. Scenario PP showed the smallest TED in XYZ-axes mean = 2.98 mm ± SD 1.33; 2.28 mm ± SD 1.45; 2.78 mm ± SD 1.91, respectively. Scenario FF showed the largest TED in XYZ-axes with mean = 10.03 mm ± SD 3.19; 6.36 mm ± SD 3.36; 16.11 mm ± SD 8.91, respectively. Multiple comparison tests, grouped in scenarios and axes, showed that the majority of scenario comparisons had significantly different TED values (p < 0.05). Y-axis always presented the smallest TED regardless of scenario tested.

Conclusion

A strictly perpendicular working sightline in relation to the 3D-model achieves the best accuracy results. Shortcomings in this technology, as an intraoperative visual cue, can be overcome by sightline correction. Incidentally, this is the preferred working angle for open surgery.

Preventing chylous ascites after right hemicolectomy with D3 extended mesenterectomy

Background

We aim to find the incidence of chylous ascites in patients undergoing D3 extended mesenterectomy and evaluate if a routine fat-reduced diet (FRD) has a prophylactic effect.

Methods

Data from 138 patients included in a D3 extended mesenterectomy trial were collected prospectively. Surgical drains and biochemical testing of drain fluid were used to find the incidence of chylous ascites among the first 39 patients, and a prophylactic fat-reduced diet was then implemented in the next 99 patients as a prophylactic measure.

Results

In the first 39 patients, we found that 16 (41.0%) developed chylous ascites. After the fat-reduced diet was implemented, 1 (1.0%) of 99 patients developed chylous ascites. Drain discharge was 150 vs. 80 mL daily, respectively, and a regression analysis shows the average leakage in the group with fat-reduced diet was 105 mL/day less than in the patients with no dietary restrictions (p < 0.001). There were no significant differences in the rate of other complications (Fisher exact test, one-tailed p = 0.8845), and although there was a tendency to a shorter hospital stay when given a fat-reduced diet (7.3 ± 5.4 vs. 8.9 ± 4.9 days), the difference was not significant (p = 0.19).

Conclusions

Chylous ascites is a very common postoperative occurrence after right colectomy with extended D3 mesenterectomy and may be prevented using a routine fat-reduced diet.

A three-dimensional computed tomography angiography study of the anatomy of the accessory middle colic artery and implications for colorectal cancer surgery

Purpose

In the present study, we focused on the accessory middle colic artery and aimed to increase the safety and curative value of colorectal cancer surgery by investigating the artery course and branching patterns.

Methods

We included 143 cases (mean age, 70.4 ± 11.2 years; 86 males) that had undergone surgery for neoplastic large intestinal lesions at the First Department of Surgery at Yamagata University Hospital between August 2015 and July 2018. We constructed three-dimensional (3D) computed tomography (CT) angiograms and fused them with reconstructions of the large intestines. We investigated the prevalence of the accessory middle colic artery, the variability of its origin, and the prevalence and anatomy of the arteries accompanying the inferior mesenteric vein at the same level as the origin of the inferior mesenteric artery.

Results

Accessory middle colic artery was observed in 48.9% (70/143) cases. This arose from the superior mesenteric artery in 47, from the inferior mesenteric artery in 21, and from the celiac artery in two cases. In 78.2% (112/143) cases, an artery accompanying the inferior mesenteric vein was present at the same level as the origin of the inferior mesenteric artery; this artery was the left colic artery in 92, the accessory middle colic artery in 11, and it divided and became the left colic artery and the accessory middle colic artery in 10 cases.

Conclusion

3D CT angiograms are useful for preoperative evaluation. Accessory middle colic arteries exist and were observed in 14.9% of cases.

Vascular anatomy of the splenic flexure, focusing on the accessory middle colic artery and vein

AIM

Recently, the accessory middle colic artery (AMCA) has been recognized as the vessel that supplies blood to the splenic flexure. However, the positional relationship between the AMCA and inferior mesenteric vein (IMV) has not been evaluated. Herein, we aimed to evaluate the anatomy of the AMCA and the splenic flexure vein (SFV).

METHOD

Two hundred and five patients with colorectal cancer who underwent enhanced CT preoperatively were enrolled in the present study. The locations of the AMCA and IMV were evaluated, focusing on the positional relationship between the vessels and pancreas - below the pancreas or to the dorsal side of the pancreas.

RESULTS

The AMCA was observed in 74 (36.1%) patients whereas the SFV was found in 177 (86.3%) patients. The left colic artery (LCA) was the major artery accompanying the SFV in 87 (42.4%) of patients. The AMCA accompanied the SFV in 65 (32.7%) patients. In 15 (7.8%) patients, no artery accompanied the SFV. The origin of the AMCA was located on the dorsal side of the pancreas in 15 (20.3%) of these 74 patients. Similarly, the destination of the IMV was located on the dorsal side of the pancreas in 65 (31.7%) of patients.

CONCLUSION

The SFV was observed in most patients, and the LCA or AMCA was the common accompanying artery. In some patients these vessels were located on the dorsal side of the pancreas and not below it. Preoperative evaluation of this anatomy may be beneficial for lymph node dissection during left-sided hemicolectomy.

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.

Vascular anatomical variation in laparoscopic right hemicolectomy

Laparoscopic complete mesocolic excision is gradually becoming the standard surgical approach in colon cancer therapy, the core element of which is central vascular ligation. However, this increases the difficulty for surgeons, particularly in the context of right colectomy, which encounters complex vascular anatomy. This study aimed to examine vascular variations that occur during laparoscopic right hemicolectomy through a review of the medical literature. We demonstrated that the ICA and MCA are evident in the majority of patients. The RCA was inconsistently present ranging from 12% to 45%. The ICA passed the SMV anteriorly or posteriorly at average rates. However, the RCA passed anterior to the SMV in most patients. Regarding intravenous, the ICV was consistently present, whereas the RCV was absent in up to 80% of patients. The GTH was present in nearly 80% of patients. We classified the vascular variations by the location of the branches instead of using numerical classification. The GCT and GPCT were common types whilst the GPT was relatively rare. In summary, detailed information on the vascular anatomical variations occurring on the right-side of the colon is vital. Failure to identify variations during surgical procedures can result in unwanted bleeding. Thus, we advocate for the use of the ICV as an anatomic marker during surgery.

Complete mesocolic excision for colonic cancer

INTRODUCTION

Complete mesocolic excision for colonic cancer is similar in concept to total mesorectal excision for rectal cancer. This review aims to provide the embryological and anatomical rationale behind CME, and to review the current literature on CME, relative to the feasibility via laparoscopy, the oncological adequacy and outcomes.

EVIDENCE ACQUISITION

A literature search was performed at the end of 2017 according the PRISMA guidelines for systematic reviews. Of 3980 articles found, we analyzed 96 articles. Of note, many case series had overlapping populations; there were five review articles, two consensus conference proceedings, six comparative but only one randomized trial.

EVIDENCE SYNTHESIS

The embryonic and anatomical rationale is well described. CME is feasible via laparoscopy, which may facilitate dissection and anatomic precision: no statistically significant differences were found when compared to open CME regarding overall survival. However, morbidity may be higher in the hands of non-expert laparoscopic surgeons.

CONCLUSIONS

Oncological adequacy can be obtained with laparoscopic CME, with increased lymph node retrieval. However, until now, there is no formal proof that CME improves local recurrence or survival.

Surgical treatment of rectal cancer with a Retzius shunt: a case report

Background

A case of a short circuit (Retzius shunt) from the inferior mesenteric vein (IMV) to the inferior vena cava (IVC) without accompanying portal hypertension due to liver cirrhosis is rare.

Case presentation

An 83-year-old woman who was followed after surgery for thyroid and breast cancer was incidentally found to have rectal cancer on computed tomography (CT). Preoperative three-dimensional CT showed a venous malformation forming a short circuit (Retzius shunt) from the IMV to the IVC. Laparoscopic anterior rectal resection was performed. Operative findings included the Retzius vein crossing the abdominal aorta and the inferior mesenteric artery (IMA) to the IVC and a number of engorged vessels in the mesentery. The Retzius vein and IMA were clipped without major bleeding, and tumor-specific mesorectal excision was then performed. The patient’s postoperative clinical course was good, and she was discharged without complications.

Conclusions

Preoperative imaging enabled identification of an unexpected rare disease, thus reinforcing the importance of preoperative imaging.

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.

Variations in right colic vascular anatomy observed during laparoscopic right colectomy

Background

This study aimed to analyze right colonic vascular variability.

Methods

The study included 60 consecutive patients who underwent laparoscopic radical right colectomy and D3 lymph node dissection for malignant colonic cancer on the ileocecal valve, ascending colon or hepatic flexure (March 2013 to October 2016). The videos of the 60 surgical procedures were collected. Variations of right colonic vascular anatomy were retrospectively analyzed based on 60 high-resolution surgical videos of laparoscopic surgery.

Results

The superior mesenteric artery and vein were present in all cases; 95.0% (57/60) had the superior mesenteric artery on the left side of the superior mesenteric vein. The ileocolic artery and vein occurred in 96.7% (58/60) and 100% (60/60) of cases, respectively; 50.0% (29/58) had the ileocolic artery passing the superior mesenteric vein anteriorly. Thirty-three (55.0%) cases had a right colic artery, and 2 (3.33%) had a double right colic artery; 90.9% (30/36) had the right colic vein passing anterior to the superior mesenteric artery. Fifty-six (93.3%) cases had a right colic vein; 7 (12.5%) had a right colic vein accompanied by a right colic artery, 66.1% (37/56) had the right colic vein draining into the gastrocolic trunk of Henle, 23.2% (13/56) had the right colic vein directly draining into superior mesenteric vein, and 10.7% (6/56) had one right colic vein draining into the superior mesenteric vein and the other into the gastrocolic trunk of Henle. Fifty-three (88.3%) cases had a gastrocolic trunk of Henle: a gastrocolic trunk in 35.8% (19/53), a gastropancreatic trunk in 9.4% (5/53), and a gastropancreaticocolic trunk in 54.7% (29/53). The frequencies of middle colic artery and vein were respectively 100% (60/60) and 93.3% (56/60).

Conclusions

Right colonic vascular variations were classified in Chinese patients. Notable findings included a superior mesenteric artery positioned to the right of the superior mesenteric vein and variation in middle colic artery length. This knowledge may be helpful to colorectal surgeons and could potentially help to improve safety by reducing vascular complications during minimally invasive procedures.

Preoperative anatomical road mapping reduces variability of operating time, estimated blood loss, and lymph node yield in right colectomy with extended D3 mesenterectomy for cancer

OBJECTIVE

To assess the impact of individual patient anatomy on operating time, estimated blood loss (EBL), and lymph node yield in right colectomy with extended D3 mesenterectomy, where surgeons have access to a preoperative 3-D reconstruction of the vascular anatomy of patients before surgery. Data on the impact of individual patient vascular anatomy when surgeons have an anatomical road map as a guide at surgery is still missing in the literature.

METHOD

Consecutive patients enrolled in an ongoing trial were classified into 4 groups and 2 subgroups using a 3-D vascular anatomy reconstruction derived from the staging CT. Outcome measures are operating time, EBL, vascular events, and D3 volume lymph node yield. SPSS was used for statistical analysis.

RESULTS

One hundred seventy-six (77 men) patients included. Mean operating time was 200 ± 50 min. Type 4b required significantly longer operating time (mean, 219 ± 59) compared to type 3 (mean, 188 ± 43) (p = 0.004). Vascular events occurred most often in anatomy type 4b (20.0%) and 3 (19.2%). No difference in EBL and lymph node yield was found (p = 0.102 and p = 0.803, respectively).

CONCLUSION

The use of a roadmap at surgery seems to even differences in operating time, EBL, and lymph node yield, independent of the complexity of the individual patient's central mesenteric vascular anatomy. The incidents of vascular events requiring hemostasis do not cause differences in EBL between the anatomy groups, suggesting that preoperative awareness of the anatomy is beneficial at surgery.

Right colectomy: a New York state of mind

Although mortality rates attributable to colon cancer have significantly improved over the past decades, it is still one of the leading causes of death in the USA. As newer technology and surgical techniques and concepts are being introduced, substantial confusion and dissenting opinions have come into fray as well. Naturally, different practice patterns emerged in Asia, Western Europe as well as in the USA. In this special article, we focus on the right colon and examine the unique challenges and oddities of practicing academic colorectal surgery in the New York metropolitan area.

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 Pancreaticoduodenectomy: a Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Mesopancreas dissection with central vascular ligation and the superior mesenteric artery (SMA)-first approach represent the cornerstone of current principles for radical resection for pancreatic head cancer. The surgeon dissecting around the SMV and SMA should be aware regarding the anatomical variants in this area. The aims of this systematic review and meta-analysis are to detail the surgical anatomy of the superior mesenteric vessels and to propose a standardized terminology with impact in pancreatic cancer surgery.

METHODS

We conducted a systematic search to identify all published studies in PubMed/MEDLINE and Google Scholar databases from their inception up to March 2017.

RESULTS

Seventy-eight studies, involving a total of 18,369 specimens, were included. The prevalence of the mesenteric-celiac trunk, replaced/accessory right hepatic artery (RRHA), common hepatic artery, and SMV inversion was 2.8, 13.2, 2.6, and 4.1%, respectively. The inferior pancreaticoduodenal artery has its origin into the first jejunal artery, SMA, and RRHA, in 58.7, 35.8, and 1.2% of cases, respectively. The SMV lacks a common trunk in 7.5% of cases. The first jejunal vein has a trajectory posterior to the SMA in 71.8% of cases. The left gastric vein drains into the portal vein in 58%, in splenic vein (SV) in 35.6%, and into the SV-PV confluence in 5.8% of cases.

CONCLUSIONS

Complex pancreaticoduodenal resections require detailed knowledge of the superior mesenteric artery and vein, which is significantly different from the one presented in the classical textbooks of surgery. We are proposing the concept of the first jejunopancreatic vein which impacts the current oncological principles of pancreatic head cancer resection.

Analysis of the Vascular Interrelationships Among the First Jejunal Vein, the Superior Mesenteric Artery, and the Middle Colic Artery

BACKGROUND

The technical difficulty of laparoscopic surgery for transverse colon cancer is partly due to the vascular variability around the middle colic vessels. Although individual variations in the arteries or veins in this area were previously investigated, the vascular interrelationships between these vessels remain unknown. This study was designed to investigate the vascular interrelationships between the arteries and veins around the middle colic vessels and to provide practically useful classifications.

METHODS

This study included 105 consecutive patients who underwent colorectal surgery for colorectal tumors in our institution in 2016. Patients with a history of colectomy were excluded. Vascular anatomical classifications were analyzed by evaluating thin-slice images of preoperative contrast-enhanced computed tomography.

RESULTS

Vascular anatomical patterns were classified according to whether the first jejunal vein ran behind (type A) or in front (type B) of the superior mesenteric artery. Type B was subclassified into two subtypes, depending on whether the middle colic artery originated cephalad (type B1) or caudad (type B2) to the first jejunal vein. We identified 83 (79.0%) cases of type A, 11 (10.5%) of type B1, and 11 (10.5%) of type B2. In 17 cases, the middle colic vein drained into the inferior mesenteric vein, and all of these were type A (P = 0.0202). Furthermore, in eight cases, the middle colic vein drained into the first jejunal vein, and all of these were type B (P < 0.0001).

CONCLUSIONS

This study elucidated the vascular interrelationships around the middle colic vessels. Our findings provided important knowledge for laparoscopic surgery in treating transverse colon cancer.

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.

Right colic artery anatomy: a systematic review of cadaveric studies

Background

Complete mesocolic excision for right-sided colon cancer may offer an oncologically superior excision compared to traditional right hemicolectomy through high vascular tie and adherence to embryonic planes during dissection, supported by preoperative scanning to accurately define the tumour lymphovascular supply and drainage. The authors support and recommend precision oncosurgery based on these principles, with an emphasis on the importance of understanding the vascular anatomy. However, the anatomical variability of the right colic artery (RCA) has resulted in significant discord in the literature regarding its precise arrangement.

Methods

We systematically reviewed the literature on the incidence of the different origins of the RCA in cadaveric studies. An electronic search was conducted as per Preferred Reporting Items for Systematic Reviews and Meta-analyses recommendations up to October 2016 using the MESH terms ‘right colic artery’ and ‘anatomy’ (PROSPERO registration number CRD42016041578).

Results

Ten studies involving 1073 cadavers were identified as suitable for analysis from 211 articles retrieved. The weighted mean incidence with which the right colic artery arose from other parent vessels was calculated at 36.8% for the superior mesenteric artery, 31.9% for the ileocolic artery, 27.7% for the root of the middle colic artery and 2.5% for the right branch of the middle colic artery. In 1.1% of individuals the RCA shared a trunk with the middle colic and ileocolic arteries. The weighted mean incidence of 2 RCAs was 7.0%, and in 8.9% of cadavers the RCA was absent.

Conclusions

This anatomical information will add to the technical nuances of precision oncosurgery in right-sided colon resections.

Detecting the Non-physiological, Surgically Tailored Ileocolic Anastomosis Using the Wireless Motility Capsule. A Pre- and Post-operative, Prospective, Within Subject Trial

Background/Aims

Wireless motility capsule (WMC) detects the ileocolic junction (ICJ) in most non-operated patients. We find no data concerning this examination in patients where the ileocolic valve is replaced by a per definition incompetent, surgically created ICJ. We wanted to see if WMC could detect the ICJ after a right colectomy and assess the competency.

Methods

Prospective cohort study using a within-subject design to eliminate subject-subject variability. Selected patients operated with right colectomy underwent 3 WMC examinations (pre-operatively, 3 weeks, and 6 months after surgery).

Results

Twenty patients (8 men) included, 7 (4 men) excluded due to poor recordings (4) and unforeseen events (3). Thirteen patients (4 men), median age 63 years completed 3 tests. Median bowel lengths removed were 11 cm for ileum and 21 cm for colon. Thirty-nine examinations analyzed by 2 physicians who found all 13 ICJs at 3 examinations with high inter-rater reliability (intra-class correlation coefficient: 0.99, 0.91, and 0.99 respectively), whereas the computer found 9, 8, and 10 out of the 13 ICJs, respectively. Computed values significantly more often deviated from the 2 raters. Mean magnitude and duration of pH-drop at the ICJ (3 examinations) was 1.16-1.02-1.13 pH units and 3.15-4.78-3.75 minutes, respectively. pH-drop was smaller and duration longer at 3 weeks. We found no differences between the pre-operative (competent ICJ) and post-operative 6-month examinations (incompetent ICJ). Highest pressure immediately prior to ICJ was equal before and after surgery.

Conclusion

WMC can identify the non-physiological ICJ after right colectomy. Ileocolic competence cannot be assessed.

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 meta-analysis 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.

Tailored Treatment of Colorectal Cancer: Surgical, Molecular, and Genetic Considerations

Colorectal cancer (CRC) is a complex cancer disease, and approximately 40% of the surgically cured patients will experience cancer recurrence within 5 years. During recent years, research has shown that CRC treatment should be tailored to the individual patient due to the wide variety of risk factors, genetic factors, and surgical complexity. In this review, we provide an overview of the considerations that are needed to provide an individualized, patient-tailored treatment. We emphasize the need to assess the predictors of CRC, and we summarize the latest research on CRC genetics and immunotherapy. Finally, we provide a summary of the significant variations in the colon and rectal anatomy that is important to consider in an individualized surgical approach. For the individual patient with CRC, a tailored treatment approach is needed in the preoperative, operative, and postoperative phase.

Intraoperative Archive of Right Colonic Vascular Variability Aids Central Vascular Ligation and Redefines Gastrocolic Trunk of Henle Variants

BACKGROUND

Vascular supply to the right colon has become an issue because of high variability and subsequent impact on minimally invasive surgery. Past cadaveric or radiologic anatomic assessments are noncomprehensive.

OBJECTIVE

Intraoperative charting of right colonic arteriovenous anatomy was undertaken to determine the incidence and scope of vascular variations.

DESIGN

Vascular anatomy variations were documented in snapshot images, captured during laparoscopic video recordings or through open surgical digital photography.

SETTINGS

Data were drawn from consecutive right hemicolectomies, routinely entailing complete mesocolic excision with central vascular ligation.

PATIENTS

Seventy patients (mean age, 62.7 years; 37 women (52.8%); 33 men (47.2%)), each with surgically treatable right-sided colon cancer, were prospectively studied.

RESULTS

Both ileocolic and middle colic arteries were regularly identified (100%), with right colic artery present in 41.4% of patients. Ileocolic and middle colic veins consistently drained into the right colon. Although the ileocolic vein always emptied into the superior mesenteric vein, drainage of the middle colic vein was split (superior mesenteric vein, 94.3%; gastrocolic trunk of Henle, 5.3%), as was drainage of the right colic (superior mesenteric vein, 43.3%; gastrocolic trunk of Henle, 56.7%) and accessory middle colic veins (superior mesenteric vein, 54.5%; gastrocolic trunk of Henle, 45.5%), present in 42.9% and 15.7% of patients. Gastrocolic trunk of Henle was found in 88.6% of patients, usually draining into the superior mesenteric vein. No significant sex-related differences were present regarding the incidence and scope of variability displayed by the right colic artery, right colic vein, accessory middle colic vein, or gastrocolic trunk of Henle classification (p > 0.05).

LIMITATIONS

The inconsistency between cadaver and live surgery anatomy and the low BMI of the Asian population might be drawbacks of our study.

CONCLUSIONS

Variations in right colonic arteriovenous channels, assessed intraoperatively, corroborate those established by cadaveric and radiologic means, prompting a new gastrocolic trunk of Henle classification.

An unusual case of colon vascularization by the inferior mesenteric artery

In this article we present a rare variant in which the large intestine was vascularized by the inferior mesenteric artery. It was encountered during macro and microscopic dissection of the cadaver of a 63-year-old woman at a university department of human anatomy. In this case, the ascending, transverse, descending, and sigmoid colon and rectum were vascularized by the inferior mesenteric artery, whereas the small intestine, cecum and appendix were supplied by the superior mesenteric artery.

Pattern of Colon Cancer Lymph Node Metastases in Patients Undergoing Central Mesocolic Lymph Node Excision: A Systematic Review

BACKGROUND

Extended mesocolic lymph node dissection in colon cancer surgery seems to improve oncological outcome. A possible reason might be related to metastases in the central mesocolic lymph nodes.

OBJECTIVE

The purpose of this study was to describe the pattern of mesocolic lymph node metastases, particularly in central lymph nodes, and the risk of skip, aberrant, and gastrocolic ligament metastases as the argument for performing extended lymph node dissection.

DATA SOURCES

EMBASE and PubMed were searched using the terms colon or colorectal with sentinel node, lymph node mapping, or skip node; lymph node resection colon; and complete or total and mesocolic excision.

STUDY SELECTION

Studies describing the risk of metastases in central, skip, aberrant, and gastrocolic ligament lymph node metastases from colon adenocarcinomas in 10 or more patients were included. No languages were excluded.

MAIN OUTCOME MEASURES

The risk of metastases in the central mesocolic lymph nodes was measured.

RESULTS

A total of 2052 articles were screened, of which 277 underwent full-text review. The 47 studies fulfilling the inclusion criteria were very heterogeneous, and meta-analyses were not considered appropriate. The risk of central mesocolic lymph node metastases for right-sided cancers varies between 1% and 22%. In sigmoid cancer, the risk is reported in ≤12% of the patients and is associated with advanced T stage.

LIMITATIONS

The retrospective design and heterogeneity, in terms of definitions of lymph node location, tumor sites, stage, morphology, pathology assessment, and inclusion criteria (selection bias), of the included studies were limitations. Also, anatomic definitions were not uniform.

CONCLUSIONS

The present literature cannot give a theoretical explanation of a better oncological outcome after extended lymph node dissection. Consensus for a standardization of anatomical definitions and surgical and pathological assessments is warranted for future mapping studies.

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.

Vascular Structures of the Right Colon: Incidence and Variations with Their Clinical Implications

BACKGROUND AND AIMS

There is a demand for a better understanding of the vascular structures around the right colonic area. Although right hemicolectomy with the recent concept of meticulous lymph node dissection is a standardized procedure for malignant diseases among most surgeons, variations in the actual anatomical vascular are not well understood. The aim of the present review was to present a detailed overview of the vascular variation pertinent to the surgery for right colon cancer.

MATERIALS AND METHODS

Medical literature was searched for the articles highlighting the vascular variation relevant to the right colon cancer surgery.

RESULTS

Recently, there have been many detailed studies on applied surgical vascular anatomy based on cadaveric dissections, as well as radiological and intraoperative examinations to overcome misconceptions concerning the arterial supply and venous drainage to the right colon. Ileocolic artery and middle colic artery are consistently present in all patients arising from the superior mesenteric artery. Even though the ileocolic artery passes posterior to the superior mesenteric vein in most of the cases, in some cases courses anterior to the superior mesenteric artery. The right colic artery is inconsistently present ranging from 63% to 10% across different studies. Ileocolic vein and middle colic vein is always present, while the right colic vein is absent in 50% of patients. The gastrocolic trunk of Henle is present in 46%-100% patients across many studies with variation in the tributaries ranging from bipodal to tetrapodal. Commonly, it is found that the right colonic veins, including the right colic vein, middle colic vein, and superior right colic vein, share the confluence forming the gastrocolic trunk of Henle in a highly variable frequency and different forms.

CONCLUSION

Understanding the incidence and variations of the vascular anatomy of right side colon is of crucial importance. Failure to recognize the variation during surgery can result in troublesome bleeding especially during minimal invasive surgery.

Bowel function and quality of life after superior mesenteric nerve plexus transection in right colectomy with D3 extended mesenterectomy

BACKGROUND

The aim of this study was to ascertain the impact of injury to the superior mesenteric nerve plexus caused by right colectomy with D3 extended mesenterectomy as performed in the prospective multicenter trial: "Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic Multi-detector Computed Tomography" in which all soft tissue surrounding the superior mesenteric vessels from the level of the middle colic artery to that of the ileocolic artery was removed.

METHODS

Bowel function and gastrointestinal quality of life in two consecutive cohorts that underwent right colectomy with and without D3 extended mesenterectomy were compared. Main outcome measures were the Diarrhea Assessment Scale (DAS) and Gastrointestinal Quality of Life Index (GIQLI). The data were collected prospectively through telephone interviews.

RESULTS

Forty-nine patients per group, comparable for age, sex, length of bowel resected but with significantly shorter follow-up time in the experimental group, were included. There was no difference in total DAS scores, subscores or additional questions except for higher bowel frequency scores in the D3 group (p = 0.02). Comparison of total GIQLI scores and subscales showed no difference between groups. Regression analysis with correction for confounding factors showed 0.48 lower bowel frequency scores in the D2 group (p = 0.022). Within the D3 group presence of jejunal arteries cranial to the D3 dissection area showed 1.78 lower DAS scores and 0.7 lower bowel frequency scores.

CONCLUSIONS

Small bowel denervation after right colectomy with D3 extended mesenterectomy leads to increased bowel frequency but does not impact gastrointestinal quality of life. Individual anatomical variants can affect postoperative bowel function differently despite standardized surgery.