Carl Toldt Centennial, Surgeon and Anatomist.

Carl Florian Toldt was an Austrian anatomist who made meaningful contributions worldwide and defined what is one of the most important surgical landmarks in abdominal surgery. Through his research studies, the embryologic dissection plane known as the "White Line of Toldt" represents an important anatomical landmark that helps to mobilize either the ascending or descending colon. His career spanned over 45 years, beginning in Verona and continuing to Prague and Vienna. He was an author of several innovative books and scientific articles regarding micro- and macroscopic anatomy. In addition, he received numerous recognitions and prizes for his work, making him an essential figure in the medical scientific community. Even a street in Vienna, Karl-Toldt-Weg, is named in his honor. The purpose of this historical article is to celebrate and honor Toldt 100 years following his death, remembering his scientific contributions to the medical and surgical fields and giving thanks for his numerous accomplishments. This article brings light to the man behind the eponym.

[Intraoperative anatomical observation of mesentery morphology of colonic splenic flexure].

Objective: At present, surgeons do not know enough about the mesenteric morphology of the colonic splenic flexure, resulting in many problems in the complete mesenteric resection of cancer around the splenic flexure. In this study, the morphology of the mesentery during the mobilization of the colonic splenic flexure was continuously observed in vivo, and from the embryological point of view, the unique mesenteric morphology of the colonic splenic flexure was reconstructed in three dimensions to help surgeons further understand the mesangial structure of the region. Methods: A total of 9 patients with left colon cancer who underwent laparoscopic radical resection with splenic flexure mobilization by the same group of surgeons in Union Hospital of Fujian Medical University from January 2018 to June 2019 were enrolled. The splenic flexure was mobilized using a "three-way approach" strategy based on a middle-lateral approach. During the process of splenic flexure mobilization, the morphology of the transverse mesocolon and descending mesocolon were observed and reconstructed from the embryological point of view. The lower margin of the pancreas was set as the axis, and 4 pictures for each patient (section 1-section 4) were taken during middle-lateral mobilization. Results: The median operation time of the splenic flexure mobilization procedure was 31 (12-55) minutes, and the median bleeding volume was 5 (2-30) ml. One patient suffered from lower splenic vessel injury during the operation and the bleeding was stopped successfully after hemostasis with an ultrasound scalpel. The transverse mesocolon root was observed in all 9 (100%) patients, locating under pancreas, whose inner side was more obvious and tough, and the structure gradually disappeared in the tail of the pancreatic body, replaced by smooth inter-transitional mesocolon and dorsal lobes of the descending colon. The mesenteric morphology of the splenic flexure was reconstructed by intraoperative observation. The transverse mesocolon was continuous with a fan-shaped descending mesocolon. During the embryonic stage, the medial part (section 1-section 2) of the transverse mesocolon and the descending mesocolon were pulled and folded by the superior mesenteric artery (SMA). Then, the transverse mesocolon root was formed by compression of the pancreas on the folding area of the transverse mesocolon and the descending mesocolon. The lateral side of the transverse mesocolon root (section 3-section 4) was distant from the mechanical traction of the SMA, and the corresponding folding area was not compressed by the tail of the pancreas. The posterior mesangial lobe of the transverse mesocolon and the descending mesocolon were continuous with each other, forming a smooth lobe. This smooth lobe laid flat on the corresponding membrane bed composed of the tail of pancreas, Gerota's fascia and inferior pole of the spleen. Conclusions: From an embryological point of view, this study reconstructs the mesenteric morphology of the splenic flexure and proposes a transverse mesocolon root structure that can be observed consistently intraopertively. Cutting the transverse mesocolon root at the level of Gerota's fascia can ensure the complete resection of the mesentery of the transverse colon.

Variations in Laminar Arrangements of the Mesocolon and Retropancreatic Fascia: a Histological Study Using Human Fetuses Near Term.

OBJECTIVE: The embryonic mesentery of the ascending and descending colons as well as the pancreas disappears due to peritoneal fusion, but there might be no or few photographic demonstrations of the intermediate morphologies during the process. The aims of this study were to characterize the morphological relationship of the interface between the renal fascia and peritoneum. METHODS: Fourteen late-stage fetuses with crown rump lengths (CRLs) of 250-325 mm (gestational age: 30-38 weeks) were histologically examined. RESULTS: The renal fascia, a thick or thin layer consisting of densely-distributed abundant fibers, was consistently separated from the renal capsule by a perirenal space containing fat. The transverse colon carried a typical mesocolon histologically different from the renal fascia. The ascending and descending mesocolons were irregularly divided into multiple laminae and the colic external longitudinal muscle appeared to directly contact the renal fascia. There was a spectrum of variations from multiple laminae to a single thick fascia between the pancreatic body and the left kidney or adrenal. CONCLUSIONS: A fascial development after retroperitoneal fusion of the mesentery showed great individual and site-dependent differences in proportion of 1) a complete fusion with the renal fascia and 2) a multilaminar structure including the remnant peritoneum. These variations masked the likely stage-dependent change.

Ex vivo specimen MRI and pathology confirm a rectosigmoid mesenteric waist at the junction of the mesorectum and mesocolon.

AIM: Continuity of the mesentery has recently been established and may provide an anatomical basis for optimal colorectal resectional surgery. Preliminary data from operative specimen measurements suggest there is a tapering in the mesentery of the distal sigmoid. A mesenteric waist in this area may be a risk factor for local recurrence of colorectal cancer. This study aimed to investigate the anatomical characteristics of the mesentery at the colorectal junction. METHOD: In this cross-sectional study, 20 patients were recruited. After planned colorectal resection, the surgical specimens were scanned in a MRI system and subsequently dissected and photographed as per national pathology guidelines. Mesenteric surface area and linear measurements were compared between MRI and pathology to establish the presence and location of a mesenteric waist. RESULTS: Specimen analysis confirmed that a narrowing in the mesenteric surface area was consistently apparent at the rectosigmoid junction. Above the anterior peritoneal reflection, the surface area and posterior distance of the mesentery of the upper rectum initially decreased before increasing as the mesentery of the sigmoid colon. These anatomical properties created the appearance of a mesenteric 'waist' at the rectosigmoid junction. Using the anterior reflection as a reference landmark, the rectosigmoid waist occurred at a mean height of 23.6 and 21.7 mm on MRI and pathology, respectively. CONCLUSION: A rectosigmoid waist occurs at the junction of the mesorectum and mesocolon, and is a mesenteric landmark for the rectum that is present on both radiology and pathology.

[Anatomical relationship between fascia propria of the rectum and visceral pelvic fascia in the view of continuity of fasciae].

Objective: To perform an anatomical observation on the extension of the mesocolon to the mesorectum and the continuity of the fasciae lining the abdomen and pelvis, in order to clarify the appropriate surgical plane of total mesorectal excision. Methods: This is an descriptive study. The operation videos of 61 cases (28 males, 33 females, median age of 61) were collected. All the patients underwent laparoscopic colorectal surgery from January 2018 to December 2018 in Yangpu Hospital, including low anterior resection for rectal cancer in 25 cases, left hemicolectomy for descending colon cancer in 15 cases, and subtotal resection of the colon for intractable constipation in 21 cases. Among these 21 constipation patients, 8 received additional modified Duhamel surgeries. Gross anatomy was performed on 24 adult cadavers provided by Department of Anatomy, Shanghai Jiaotong University School of Medicine, including 23 formalin-fixed and 1 fresh cadaver (12 males, 12 females). Sixty-one patients and 24 cadavers had no previous abdominal or pelvic surgical history. The anatomy and extension of fasciae related to descending colon, sigmoid colon and rectum, especially the morphology of Toldt fascia, and the continuities of mesocolon and mesorectum were observed carefully. The distribution characteristics of the fasciae and anatomical landmarks during laparoscopic surgery were recorded and described. Results: The anatomical study on 24 cadavers showed that visceral fascia was the densest connective tissue in the pelvic, posterolateral to the rectum, and stretched as a hammock to lift all pelvic organs. Among 61 patients undergoing laparoscopic surgery, 36 (59.0%) needed to free the left colon during operation, and Toldt fascia in the descending colon segment presented as potential, avascular and extensible loose connective tissue plane between the mesocolon and posterior Gerota fascia; 33 (54.1%) needed to free the rectum during operation, and Toldt fascia extended downward to pelvis as loose connective tissue between the fascia propria of the rectum and visceral fascia; the fascia propria of the rectum exposed completely in 32 (32/33, 97.0%) cases, which ran downward and fused with visceral fascia at the level of the fourth sacral vertebra. The anatomy of 24 cadavers also showed that fascia propria of the rectum fused with visceral fascia at the level of Waldeyer fascia. The fusion line of these two fasciae was supposed to be the extension of Waldeyer fascia. There were two avascular planes behind the rectum: one between the fascia propria of the rectum and visceral fascia, and the other between the visceral fascia and parietal fascia. In 8 constipation cases undergoing laparoscopic subtotal colon resection plus modified Duhamel operation, both mesocolon and mesorectum needed to be mobilized. It was obvious that the mesocolon of descending colon extended and became the mesocolon of sigmoid colon, and ran further into the pelvic and became the mesorectum. The colon fascia of descending colon served as the natural boundary of mesocolon extended downward as the fascia of sigmoid colon and the fascia propria of the rectum, respectively. Toldt fascia locating between mesocolon of descending colon and Gerota fascia extended to pelvis as the 'presacral space' between the fascia propria of the rectum and visceral fascia. Gerota fascia in descending colon segment extended as urogenital fascia in sigmoid colon segment and visceral fascia in the pelvis, respectively. In the cadaver anatomy study, the visceral fascia served as a corridor carrying the hypogastric nerve, and ureter was observed in 23 (23/24, 95.8%) cases. The visceral fascia passed from posterior to anterior lateral of rectum, fusing with Denonvilliers fascia in a fan shape. The pelvic plexus located exactly external to the junction of visceral fascia and Denonvilliers fascia. Pelvic splanchnic nerves went through the parietal fascia toward to the inferolateral of the pelvic plexus. Conclusion: Fascia propria of the rectum and the visceral pelvic fascia are two independent layers of fascia, and the TME surgical plane is between the fascia propria of the rectum and visceral pelvic fascia instead of between the visceral and the parietal pelvic fascia.

[Recognition of the interstitial plane of the surgical membrane in radical resection of right semicolon cancer].

According to multicenter randomized controlled trials, laparoscopic radical resection of colon cancer has the same short and long term clinical efficacy as traditional open surgery. In laparoscopic radical resection of right semicolon cancer, it is important to separate the embryonic plane of the root, and to ligate and cut off the central vascular roots. Only by separation along the membrane space can one achieve minimally invasive operation with no bleeding, and ensure the integrity of the excision of the mesangium and avoid damage of internal fascia and other organs. The mesangial distribution of the right semicolon is adjacent to the mesangium of the stomach and is connected to the mesentery of the small intestine. The pancreaticoduodenum locates between the right semicolon mesentery and the retroperitoneal subperitoneal fascia. In particular, the relationship between the anterior and posterior Treitz fascia of the pancreaticoduodenum and the Toldt space is complex, which is closely related to the feasibility of complete mesocolic excision(CME). This article introduces the distribution of intermembranous space and mesangial bed in the right semicolon, presenting the problem in CME surgery. In addition, there are key points in identifying the gap between the membranes based on the author's experience and we propose a new evaluation criteria for membrane surgical specimens, which has certain guiding significance for radical CME surgery for right semicolon cancer.

Completely medial access by page-turning approach for laparoscopic right hemi-colectomy: 6-year-experience in single center.

BACKGROUND: To investigate the safety and feasibility of the completely medial access by page-turning approach (CMAP) for laparoscopic right hemi-colectomy. METHODS: In this retrospective study, the data from 72 patients who underwent laparoscopic right hemi-colectomy with CMAP were analyzed and compared with data from 124 patients who underwent the conventional medial approach performed by the same surgical team from September 2011 to March 2017. RESULT: Complete mesocolic excision (CME) was achieved in 67 of 72 patients (93.1%) with laparoscopic CMAP. The average operation time, blood loss, and specimen length was 135.9 ± 28.3 min, 63.2 ± 32.2 ml, and 23.9 ± 4.7 cm, respectively. The number of lymph nodes harvested was 20.6 ± 7.7, the time-to-flatus was 2.5 ± 0.8 days, the time-to-fluid intake was 3.2 ± 0.8 days, and the average hospital stay was 8.9 ± 4.7 days. No intra-operative complications occurred in this study. The vessel-related complication and total post-operative complication rate was 2.78% (2/72) and 6.94% (5/72), respectively. CONCLUSIONS: Laparoscopic CMAP was an alternative approach for CME in laparoscopic right hemi-colectomy, which was proved safe and feasible for right colon cancer.

3D modelling of non-intestinal colorectal anatomy.

PURPOSE: There is a paucity of methods to model soft anatomical tissues. Accurate modelling of these tissues can be difficult with current medical imaging technology. METHODS: The aim of this research was to develop a methodology to model non-intestinal colorectal tissues that are not readily identifiable radiologically to enhance contextual understanding of these tissues and inform medical device design. The models created were used to inform the design of a novel medical device to separate the mesocolon from the retroperitoneum during resection of the colon. We modelled the peritoneum and the mesentery. The mesentery was used to indicate the location of Toldt's fascia. RESULTS: We generated a point cloud dataset using cryosection images as the target anatomy is more visible than in CT or MRI images. The thickness of the mesentery could not be accurately determined as point cloud data do not have thickness. A denser point cloud detailing the mesenteric boundaries could be used to address this. CONCLUSIONS: Expert anatomical and surgical insight and point cloud data modelling methods can be used to model soft tissues. This research enhances the overall understanding of the mesentery and Toldt's fascia in the human specimen which is necessary for medical device innovations for colorectal surgical procedures.

Variation in landmarks for the rectum: an MRI study.

AIM: This study aimed to assess the reliability of measurements and bony landmarks for the rectosigmoid junction on MRI. METHOD: The staging MRI scans for 100 patients were reviewed. The junction of the mesorectum and mesocolon was used to identify the rectum and sigmoid. The performance of current metric measurements or bony landmarks was then compared against the actual anatomical bowel segment. RESULTS: The mean distance of the sigmoid take-off from the anal verge was 12.6 cm (SD 1.8 cm, range 9.4-19.0 cm). At a cutoff of 12 cm, the anatomical bowel segment was found to be sigmoid colon rather than rectum in 35% of patients. At 15 and 16 cm the bowel segment was sigmoid in 84% and 96% of patients, respectively. At the sacral promontory and the third sacral segment, the bowel segment was sigmoid in 28% and 100% of patients, respectively. CONCLUSION: Current definitions of the rectum that rely on arbitrary measurements or bony landmarks will not locate the correct point of transition between the rectum and sigmoid in the majority of patients. The sigmoid take-off offers an alternative, anatomically bespoke, landmark.

Anatomical and embryological perspectives in laparoscopic complete mesocoloic excision of splenic flexure cancers.

BACKGROUND: Laparoscopic complete mesocoloic excision (CME) with central vascular ligation for splenic flexure cancer is technically challenging because of its anatomical complexity. Although embryological and anatomical consideration should be helpful to perform CME in colorectal cancer surgery, such studies on the splenic flexure are lacking. METHODS: The splenic flexure is located embryologically between the terminal portion of the midgut and the beginning of the hindgut, and is supplied by the superior mesenteric and inferior mesenteric arteries. The mesentery of the transverse and descending colon originally is a continuous sheet, although they rotate and partially fuse to each other during development. Our surgical strategy was excision of the transverse and descending mesocolon with ligation of the left colic artery and left branch of the middle colic artery, and extraction of the specimen in an intact package wrapped by the embryological planes. RESULTS: We performed laparoscopic surgery according to our surgical strategy in 17 patients with splenic flexure colon cancer. There were no conversions to open surgery or serious intraoperative complications. Two patients had pathological stage (pStage) I, 5 pStage II, 9 pStage III, and 1 pStage IV disease. No patient had recurrence except for 1 with pStage IV cancer, with a median follow-up of 16 months. CONCLUSIONS: Our laparoscopic CME technique is feasible for treatment of splenic flexure cancer. Knowledge of anatomy based on embryology is essential to perform this surgery.

[Anatomical structures relevant to complete mesocolic excision: mesentery, fascia and space].

Anatomy is the foundation of surgical techniques. With the development of surgery, anatomy also divided into traditional anatomy, surgical anatomy and embryonic development anatomy. Complete mesocolic excision (CME) is one of classic radical operation for colon cancer, based on the modern anatomy. CME advocates correct operation plane, and describes the mobilization and separation of the colon together with the entire regional mesocolon. With the evolution of anatomy, the definition and content of CME-related anatomic landmarks such as mesentery, fascia and space have been changed. This article elaborates theses anatomical structures and their distribution, in order to improve the understanding of colorectal surgeons on CME-related traditional anatomy, surgical anatomy and embryonic developmental anatomy.

Transanal total mesorectal excision: dissection tips using 'O's and 'triangles'.

PURPOSE: Transanal total mesorectal excision (taTME) requires specific technical expertise, as it is often difficult to ascertain the correct dissection plane. Consequently, one can easily enter an incorrect plane, potentially resulting in bleeding (sidewall or presacral vessels), autonomic nerve injury and urethral injury. We aim to demonstrate specific visual features, which may be encountered during surgery and can guide the surgeon to perform the dissection in the correct plane. METHOD: Specific features of dissection in the correct and incorrect planes are demonstrated in the accompanying video. RESULTS: The 'triangles' created using appropriate traction can aid in performing a precise dissection in the correct plane. Recognition of features described as 'O's can alert surgeons that they are entering a new fascial plane and can avoid incursion into an incorrect plane. CONCLUSION: Understanding and recognizing the described features which can be encountered in taTME surgery, a safe and accurate TME dissection can be facilitated.

Three surgical planes identified in laparoscopic complete mesocolic excision for right-sided colon cancer.

BACKGROUND: Complete mesocolic excision provides a correct anatomical plane for colon cancer surgery. However, manifestation of the surgical plane during laparoscopic complete mesocolic excision versus in computed tomography images remains to be examined. METHODS: Patients who underwent laparoscopic complete mesocolic excision for right-sided colon cancer underwent an abdominal computed tomography scan. The spatial relationship of the intraoperative surgical planes were examined, and then computed tomography reconstruction methods were applied. The resulting images were analyzed. RESULTS: In 44 right-sided colon cancer patients, the surgical plane for laparoscopic complete mesocolic excision was found to be composed of three surgical planes that were identified by computed tomography imaging with cross-sectional multiplanar reconstruction, maximum intensity projection, and volume reconstruction. For the operations performed, the mean bleeding volume was 73±32.3 ml and the mean number of harvested lymph nodes was 22±9.7. The follow-up period ranged from 6-40 months (mean 21.2), and only two patients had distant metastases. CONCLUSIONS: The laparoscopic complete mesocolic excision surgical plane for right-sided colon cancer is composed of three surgical planes. When these surgical planes were identified, laparoscopic complete mesocolic excision was a safe and effective procedure for the resection of colon cancer.

Mesocolic Lymph Node Number, Size, and Density: An Anatomical Study.

BACKGROUND: Lymph nodes play a critical role in the staging, treatment, and prognosis of colon cancer. However, the normal number and morphology of lymph nodes in the normal mesocolon is unknown. OBJECTIVE: This study aimed to investigate the number and size of lymph nodes in the ascending and sigmoid mesocolons. DESIGN: This is a descriptive anatomical cadaver study of 10 sigmoid mesocolons and 5 ascending mesocolons, resected in a standardized manner and examined systematically after serial histological sectioning. The number, maximum length, and appearance of lymph nodes were analyzed, and the 2 mesocolons were compared by using the Mann-Whitney U test, the Wilcoxon signed rank test, and the χ test. PATIENTS: Ten cadavers (mean age, 82.9 years; 5 male) with no evidence of colorectal disease were examined. MAIN OUTCOME MEASURE: The number, maximum length, and appearance of lymph nodes and fat-associated lymphoid clusters were the primary outcomes measured. RESULTS: The median number of lymph nodes in the sigmoid and ascending mesocolons was 71 (range, 24-116) and 61 (range, 33-71). More than 90% of lymph nodes were less than 5 mm in maximum length. Sigmoid mesocolic nodes were significantly smaller than ascending mesocolic nodes (median maximum lymph nodes length, 1.6 mm vs 2.1 mm; p < 0.001), but there was no statistically significant difference in the density of lymph nodes between the sigmoid and ascending mesocolon. Fatty replacement was seen in almost 30% of lymph nodes. A few fat-associated lymphoid clusters were observed in both mesocolons. LIMITATIONS: Only 15 mesocolic specimens could be examined because of the detailed labor-intensive methodology, and younger cadavers were not available for analysis. CONCLUSIONS: In this descriptive anatomical study, the median number of lymph nodes in the sigmoid and ascending mesocolon was 71 and 61. Ascending mesocolic nodes were significantly larger than sigmoid mesocolic nodes. These anatomical findings are relevant to the interpretation of lymph node yields after the surgical resection of colon cancer.

Terminology and nomenclature in colonic surgery: universal application of a rule-based approach derived from updates on mesenteric anatomy.

Recent developments in colonic surgery generate exciting opportunities for surgeons and trainees. In the first instance, the anatomy of the entire mesenteric organ has been clarified and greatly simplified. No longer is it regarded as fragmented and complex. Rather it is continuous from duodenojejunal flexure to mesorectum, spanning the gastrointestinal tract between. Recent histologic findings have demonstrated that although apposed to the retroperitoneum, the mesenteric organ is separated from this via Toldt's fascia. These fundamentally important observations underpin the principles of complete mesocolic excision, where the mesocolic package is maintained intact, following extensive mesenterectomy. More importantly, they provide the first opportunity to apply a canonical approach to the development of nomenclature in resectional colonic surgery. In this review, we demonstrate how the resultant nomenclature is entirely anatomic based, and for illustrative purposes, we apply it to the procedure conventionally referred to as right hemicolectomy, or ileocolic resection.

The normal transverse mesocolon and involvement of the mesocolon in acute pancreatitis: an MRI study.

OBJECTIVE: To study the MRI findings of the normal transverse mesocolon and the involvement of the mesocolon in acute pancreatitis (AP) as well as the relationship between the involvement of the mesocolon and the severity of AP. MATERIALS AND METHODS: Forty patients without pancreatic disorders were retrospectively analyzed to observe the normal transverse mesocolon using MRI; 210 patients with AP confirmed by clinical and laboratory tests were retrospectively analyzed using MRI to observe transverse-mesocolon involvement (TMI). The severity of TMI was recorded as zero points (no abnormalities and transverse-mesocolon vessel involvement), one point (linear and patchy signal in the transverse mesocolon) or two points (transverse-mesocolon effusion). The AP severity was graded by the MRI severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation II (APACHE II) scoring system. The correlations of TMI with MRSI and APACHE-II were analyzed. RESULTS: In a normal transverse mesocolon, the display rates of the middle colic artery, the middle colic vein and the gastrocolic trunk on MRI were 95.0%, 82.5% and 100.0%, respectively. Of the 210 patients with AP, 130 patients (61.9%) had TMI. According to the TMI grading, 40%, 39% and 20% of the patients were graded at zero, one and two points, respectively. TMI was strongly correlated with the MRSI score (r = 0.759, P = 0.000) and the APACHE-II score (r = 0.384, P = 0.000). CONCLUSION: MRI could be used to visualize transverse-mesocolon involvement. The severity of TMI could reflect that of AP in the clinical setting and imaging. TMI might be a supplementary indicator of the severity of AP.

La vía supramesocólica de acceso al pedículo renal izquierdo: descripción de anatomía quirúrgica / Supramesocolic approach to the left renal pedicle: Description of the surgical anatomy

OBJETIVO: Exponer y recordar la vía de acceso supramesocólica al pedículo renal izquierdo, además de recordar las principales indicaciones de la misma. MÉTODO/RESULTADOS: Realizamos una descripción detallada de la técnica quirúrgica exponiendo sus indicaciones, la posición, incisión y sistemas de retracción utilizados y detallando los pasos llevados a cabo durante la disección. CONCLUSIÓN: El adecuado control vascular y la resección completa de grandes masas renales y suprarrenales precisan de una adecuada exposición; por lo que el conocimiento de técnicas quirúrgicas como el acceso supramesocólico al pedículo renal izquierdo es de gran utilidad y que puede facilitar el curso de cirugías retroperitoneales evitando complicaciones y aportando comodidad a actuaciones con frecuencia comprometidas

OBJECTIVE: To expose and remind the supamesocolic approach to the left renal pedicle, in addition to review its main indications. METHODS/RESULTS: We perform a detailed description of the surgical technique showing its indications, the position, the incision and retraction systems employed, detailing the steps followed during dissection. CONCLUSIONS: Adequate vascular control and complete resection of large renal and adrenal masses require an adequate exposition; the knowledge of surgical techniques such as supramesocolic approach to the left renal pedicle is very useful and may ease the course of retroperitoneal operations avoiding complications and giving comfort in a frequently difficult operation

Lymph node distribution in the d3 area of the right mesocolon: implications for an anatomically correct cancer resection. A postmortem study.

BACKGROUND: Data on lymph node distribution in the right colon D3 area are scarce, especially for nodes posterior to the superior mesenteric vessels. OBJECTIVE: The aim of this study was to determine whether nodes exist posterior to the superior mesenteric vessels and if arterial crossing patterns affect node distribution. DESIGN: This is an anatomical postmortem study. SETTINGS: This study was conducted at the following institutions: Department of Gastrointestinal surgery/Pathology, Vestfold Hospital Trust, Norway; Institute for Pathology, University of Belgrade, Serbia; and Anatomy Sector, University of Geneva, Switzerland. PATIENTS: Fresh human cadavers were selected to undergo autopsy. INTERVENTION: A predefined D3 area was removed from cadavers, fixed in formaldehyde, divided into 3 vertical compartments with regard to the superior mesenteric vessels. Vertical compartments were further divided into 8 compartments. Millimeter slices were analyzed at histology. MAIN OUTCOME MEASURES: Lymph nodes ≥1 mm were counted in each compartment. RESULTS: Twenty-six cadavers (14 men), median age 76 years, were included. Mean node number per cadaver was 15.9 ± 7.4. Lateral, anterior, and posterior vertical compartments contained median 5.5 (1-11), 5 (2-21), and 5 (0-11) nodes. The effect of the ileocolic artery crossing pattern on node number in the posterior vertical compartment was p = 0.020. Anterior/posterior ileocolic artery compartments contained nodes in 58% and 85% cadavers with median of 1(0-7) and 2(0-5). These compartments showed a significant difference in node numbers depending on the ileocolic artery crossing pattern, p < 0.001 (posterior crossing) and p < 0.001 (anterior crossing). The middle colic artery compartment contained nodes in all cadavers with a median of 2 (1-4). The association between volume and total number of nodes in the D3 area was statistically significant, p < 0.001. LIMITATIONS: Nodes posterior to the superior mesenteric vessels do not necessarily have clinical relevance. CONCLUSION: Anatomically correct D3 resection implies posterior vertical compartment removal with posterior ileocolic artery crossing. Addition of the lateral vertical compartment to routine right colectomy has an improvement potential of 5 to 6 nodes.