Establishing correlations between normal pancreatic and submandibular gland ducts.

BACKGROUND: The objectives of this study were to evaluate the relationship between ductal morphometry and ramification patterns in the submandibular gland and pancreas in order to validate their common fractal dimension. METHODS: X-ray ductography with software-aided morphometry were obtained by injecting barium sulphate in the ducts of post-mortem submandibular gland and pancreas specimens harvested from 42 adult individuals. RESULTS: Three cases were excluded from the study because of underlying pathology. There was a significant correlation between the length of the main pancreatic duct (MPD) and the intraglandular portion of the right submandibular duct (SMD) (r = 0.3616; p = 0.028), and left SMD (r = 0.595; p < 0.01), respectively, but their maximal diameters did not correlate (r = 0.139-0.311; p > 0.05). Both dimensions of the SMD showed a significant right-left correlation (p < 0.05). The number of MPD side branches (mean = 37) correlated with the number of side branches of left SMD, but not with the right one (mean = 9). Tortuosity was observed in 54% of the MPD, 32% of the right SMD, and 24% of the left SMD, with mutual association only between the two salivary glands. CONCLUSIONS: Although the length of intraglandular SMD and MPD correlate, other morphometric ductal features do not, thus suggesting a more complex relationship between the two digestive glands.

Re-interpreting mesenteric vascular anatomy on 3D virtual and/or physical models: positioning the middle colic artery bifurcation and its relevance to surgeons operating colon cancer.

BACKGROUND: The impact of the position of the middle colic artery (MCA) bifurcation and the trajectory of the accessory MCA (aMCA) on adequate lymphadenectomy when operating colon cancer have as of yet not been described and/or analysed in the literature. The aim of this study was to determine the MCA bifurcation position to anatomical landmarks and to assess the trajectory of aMCA. METHODS: The colonic vascular anatomy was manually reconstructed in 3D from high-resolution CT datasets using Osirix MD and 3-matic Medical and analysed. CT datasets were exported as STL files and supplemented with 3D printed models when required. RESULTS: Thirty-two datasets were analysed. The MCA bifurcation was left to the superior mesenteric vein (SMV) in 4 (12.1%), in front of SMV in 17 (53.1%) and right to SMV in 11 (34.4%) models. Median distances from the MCA origin to bifurcation were 3.21 (1.18-15.60) cm. A longer MCA bifurcated over or right to SMV, while a shorter bifurcated left to SMV (r = 0.457, p = 0.009). The main MCA direction was towards right in 19 (59.4%) models. When initial directions included left, the bifurcation occurred left to or anterior to SMV in all models. When the initial directions included right, the bifurcation occurred anterior or right to SMV in all models. The aMCA was found in 10 (31.3%) models, following the inferior mesenteric vein (IMV) in 5 near the lower pancreatic border. The IMV confluence was into SMV in 18 (56.3%), splenic vein in 11 (34.4%) and jejunal vein in 3 (9.4%) models. CONCLUSION: Awareness of the wide range of MCA bifurcation positions reported is crucial for the quality of lymphadenectomy performed. The aMCA occurs in 31.3% models and its trajectory is in proximity to the lower pancreatic border in one half of models, indicating that it needs to be considered when operating splenic flexure cancer.

Re-interpreting mesenteric vascular anatomy on 3D virtual and/or physical models, part II: anatomy of relevance to surgeons operating splenic flexure cancer.

BACKGROUND: The splenic flexure is irrigated from two vascular areas, both from the middle colic and the left colic artery. The challenge for the surgeon is to connect these two vascular areas in an oncological safe procedure. MATERIALS AND METHODS: The vascular anatomy, manually 3D reconstructed from 32 preoperative high-resolution CT datasets using Osirix MD, Mimics Medical and 3-matic Medical Datasets, were exported as STL-files, video clips, stills and supplemented with 3D printed models. RESULTS: Our first major finding was the difference in level between the middle colic and the inferior mesenteric artery origins. We have named this relationship a mesenteric inter-arterial stair. The middle colic artery origin could be found cranial (median 3.38 cm) or caudal (median 0.58 cm) to the inferior mesenteric artery. The lateral distance between the two origins was 2.63 cm (median), and the straight distance 4.23 cm (median). The second finding was the different trajectories and confluence pattern of the inferior mesenteric vein. This vein ended in the superior mesenteric/jejunal vein (21 patients) or in the splenic vein (11 patients). The inferior mesenteric vein confluence could be infrapancreatic (17 patients), infrapancreatic with retropancreatic arch (7 patients) or retropancreatic (8 patients). Lastly, the accessory middle colic artery was present in ten patients presenting another pathway for lymphatic dissemination. CONCLUSION: The IMV trajectory when accessible, is the solution to the mesenteric inter-arterial stair. The surgeon could safely follow the IMV to its confluence. When the IMV trajectory is not accessible, the surgeon could follow the caudal border of the pancreas.

Reconstructing topography and extent of injury to the superior mesenteric artery plexus in right colectomy with extended D3 mesenterectomy: a composite multimodal 3-dimensional analysis.

BACKGROUND: Superior mesenteric artery plexus (SMAP) injury is reported to cause postoperative intractable diarrhea after pancreatic/colonic surgery with extended lymphadenectomy. This study aims to describe the SMAP microanatomy and extent of injury after right colectomy with extended D3 mesenterectomy for cancer. METHODS: Three groups (I) anatomical dissection, (II) postmortem histology, and (III) surgical specimen histology were included. Nerve count and area were compared between groups II and III and paravascular sheath thickness between groups I and II. 3D models were generated through 3D histology, nanoCT scanning, and finally through 3D printing. RESULTS: A total of 21 specimens were included as follows: Group (I): 5 (3 females, 80-93 years), the SMAP is a complex mesh surrounding the superior mesenteric artery (SMA), branching out, following peripheral arteries and intertwining between them, (II): 7 (5 females, 71-86 years), nerve count: 53 ± 12.42 (38-68), and area: 1.84 ± 0.50 mm2 (1.16-2.29), and (III): 9 (5 females, 55-69 years), nerve count: 31.6 ± 6.74 (range 23-43), and area: 0.889 ± 0.45 mm2 (range 0.479-1.668). SMAP transection injury is 59% of nerve count and 48% of nerve area at middle colic artery origin level. The median values of paravascular sheath thickness decreased caudally from 2.05 to 1.04 mm (anatomical dissection) and from 2.65 to 1.17 mm (postmortem histology). 3D histology models present nerve fibers exclusively within the paravascular sheath, and lymph nodes were observed only outside. NanoCT-derived models reveal oblique nerve fiber trajectories with inclinations between 35° and 55°. Two 3D-printed models of the SMAP were also achieved in a 1:2 scale. CONCLUSION: SMAP surrounds the SMA and branches within the paravascular sheath, while bowel lymph nodes and vessels lie outside. Extent of SMAP injury on histological slides (transection only) was 48% nerve area and 59% nerve count. The 35°-55° inclination range of SMAP nerves possibly imply an even larger injury when plexus excision is performed (lymphadenectomy). Reasons for later improvement of bowel function in these patients can lie in the interarterial nerve fibers between SMA branches.

Stool dynamics after extrinsic nerve injury during right colectomy with extended D3-mesenterectomy.

INTRODUCTION: To improve oncological outcome in right colon cancer surgery, an extended mesenterectomy (D3) is under evaluation. In this procedure, all tissue anterior and posterior to the superior mesenteric vessels from the middle colic to ileocolic artery origin is removed, causing injury to the superior mesenteric nerve plexus. The aim was to study the effects of this injury on bowel dynamics and quality of life (QoL). METHODS: Patients undergoing right colectomy with conventional D2- and extended D3-mesenterectomy were asked to record stool number and consistency for 60 d after surgery and complete questionnaires regarding QoL and bowel function (BF) before and after recovery from surgery. We compared early postoperative stool dynamics and long-term QoL in the groups and presented graphs depicting the temporal profile of stool numbers and consistency. RESULTS: Thirty-three patients operated with a D3-resection and 12 patients with a D2-resection participated. The results revealed significantly higher stool numbers in the D3-group until day 26, with significantly more loose-watery stools until day 40. The most pronounced difference was found on day 9 (Mean difference in the total number of stools: 2.25 stools/day, p=.004. Mean difference in loose-watery stools/day: 2.81 p<.001). About 25% in the D2- and 69.7% in the D3-group reported having more than three stools/day in the early postoperative phase. There were no differences in long-term QoL and BF between the groups except in stool consistency (p=.039). DISCUSSION/CONCLUSIONS: Denervation following extended D3-mesenterectomy leads to transitory reduced consistency and increased frequency. It does not affect long-term QoL or BF.

Semi-automated vs. manual 3D reconstruction of central mesenteric vascular models: the surgeon's verdict.

BACKGROUND: 3D vascular anatomy roadmaps are currently being implemented for surgical planning and navigation. Quality of the reconstruction is critical. The aim of this article is to compare anatomical completeness of models produced by manual and semi-automatic segmentation. METHODS: CT-datasets from patients included in an ongoing trial, underwent 3D vascular reconstruction applying two different segmentation methods. This produced manually-segmented models (MSMs) and semi-automatically segmented models (SAMs) which underwent a paired comparison. Datasets were delivered for reconstruction in 4 batches of 6, of which only batch 4 contained patients with abnormal anatomy. Model completeness was assessed quantitatively using alignment and distance error indexes and qualitatively with systematic inspection. MSMs were the gold standard. Assessed vessels were those of interest to the surgeon performing D3-right colectomy. RESULTS: 24 CT-datasets (13 females, age 44-77) were used in a paired comparative analysis of 48 3D-models. Quantitatively, SAMs showed structural improvement from Batch 1 to 3. Batch 4, with abnormal vessels, showed the highest error-index values. Qualitatively, 91.7% of SAMs did not contain all mesenteric branches relevant to the surgeon. In SAMs, 1 (12.5%) right colic artery-RCA scored as a complete vessel. 3 (37.5%) RCAs scored as incomplete and 4 (50%) RCAs were absent. 6 (25%) of 24 middle colic arteries-MCA scored as complete vessels. 11 (45.8%) scored as incomplete while 7 (29.2%) MCAs were absent. 13 (54.2%) of 24 ileocolic arteries-ICA were complete vessels. 11 (45.8%) scored as incomplete. None (0%) were absent. Additionally, it was observed that 10 (41.7%) of SAMs contained all their jejunal arteries, when compared to MSMs. Calibers of "complete" vessels were significantly higher than in "missing" vessels (MCA p < 0.001, RCA p = 0.016, ICA p < 0.001, JAs p < 0.001). CONCLUSION: Despite acceptable results from quantitative analysis, qualitative comparison indicates that semi-automatically generated 3D-models of the central mesenteric vasculature could cause considerable confusion at 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.

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.

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.

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.

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).

Defining minimal clearances for adequate lymphatic resection relevant to right colectomy for cancer: a post-mortem study.

BACKGROUND: There has been a lengthy discussion on the extent of lymphatic resection for right-sided colon cancer and the central borders of the mesentery that are not yet defined. The objectives of this study are to define minimal clearances for adequate lymphatic resection in regard to colic artery origins and the superior mesenteric artery (SMA) and vein (SMV) relevant to right colectomy. METHODS: Central mesenteric lymph vessels, nodes, and blood vessels were dissected in 16 cadavers. Cranial-caudal clearances were defined as distances between an individual colic artery origin (ileocolic, right colic, and median colic artery) and the outermost lymphatic vessel within its lymphovascular bundle, cranial and caudal along the SMA. Long lymphatic vessels crossing the SMV between arterial bundles were counted and they constituted the medial clearances. An arbitrary watershed between small bowel and colonic lymph was localized. Immunohistochemistry was performed to histologically verify lymphatic vessels. RESULTS: Cranial-caudal clearances were ileocolic 3.6 ± 1.9 and 5.7 ± 1.9; right colic 2.8 ± 1.6 and 3.3 ± 1.0; middle colic artery bundle 6.3 ± 2.7 and 5.9 ± 2.4 mm, respectively. Long lymphatic vessels crossing the SMV between arterial buntles and approaching the SMA were found in all cadavers (antero/posteriorly in 12, only anteriorly in 4), median 3.5 (1-7) long lymphatic vessels anteriorly, and 1.5 (0-5) posteriorly per cadaver. CONCLUSIONS: Right colonic lymphovascular bundles are volumes of mesenteric tissue that surround the superior mesenteric vessels anteriorly and posteriorly. Long lymphatic vessels traverse the superior mesenteric vein anteriorly/posteriorly approaching the superior mesenteric artery between arterial bundles and placing the medial clearance on the left side of the artery. These do not correlate to arterial crossing patterns. Cranial-caudal clearances determine the tissue to be removed superior/inferior to arterial origins together with long lymphatic vessels transversing independently between the lymphovascular bundles placing the weight of lymphatic resection on the mesenteric tissue and not on the level of vessel division (High tie).

Additional muscular slip of the flexor digitorum longus muscle to the fifth toe.

Despite the fact that there are numerous reports on muscular variations in the sole of the foot, routine dissection in a formaldehyde-fixed cadaver revealed an accessory flexor digiti quinti muscle, which to the best of our knowledge is a very unusual variant. This was in the form of a slender, 38 mm long muscular slip, with a proximal and distal tendon extending from the common flexor digitorum longus tendinous plate out to the distal phalanx of the fifth toe. An associated finding was the absence of the musculotendinous portion of the flexor digitorum brevis to the same toe. A developmental explanation for this variation is presented. Clinical implications with regard to this anatomical condition may result in clawing of the fifth toe.

Comment to Jejunal Diverticulitis Mimicking Small Bowel Perforation: Case Report and Review of the Literature.

Dear Editor, I would like to congratulate the authors of this well written article and to thank them for the contribution to the literature. There is, however, one point that needs to be addressed, and that is the outcomes of surgical versus conservative treatment. Areview article1 has published data on 266 patients (106 patients derived from published case reports containing individual patient data, 113 patients derived from the Norwegian patient registry and data on 47 patients as historical controls from a previous publication and used as historical controls(Chendrasekhar et al2). It seems that conservatively treated patients had similar hospital length of stay as operated patients. Age did correlate with hospital stay, howeverno difference in outcomes for operated or non-operated patients was found. The historical control group did show a significantly higher mortality, implying that attempting conservative therapy after diagnosis through an abdominal CT scan (which often does show pneumoperitoneum) can only benefit this frail patient group.