New method for analysing spatial relationships of facial muscles on MRI: a pilot study.

Dysfunction of the facial musculature can have significant physical, social, and psychological consequences. In surgeries such as cleft surgery or craniofacial bimaxillary osteotomies, the perioral facial muscles may be detached or severed, potentially altering their functional vectors and mimicry capabilities. Ensuring correct reconstruction and maintenance of anatomical sites and muscle vectors is crucial in these procedures. However, a standardized method for perioperative assessment of the facial musculature and function is currently lacking. The aim of this study was to develop a workflow to analyse the three-dimensional vectors of the facial musculature using magnetic resonance imaging (MRI) scans. A protocol for localizing the origins and insertions of these muscles was established. The protocol was implemented using the 3DMedX computer program and tested on 7 Tesla MRI scans obtained from 10 healthy volunteers. Inter- and intra-observer variability were assessed to validate the protocol. The absolute intra-observer variability was 2.6 mm (standard deviation 2.0 mm), and absolute inter-observer variability was 2.6 mm (standard deviation 1.5 mm). This study presents a reliable and reproducible method for analysing the spatial relationships and functional significance of the facial muscles. The workflow developed facilitates perioperative assessment of the facial musculature, potentially aiding clinicians in surgical planning and potentially enhancing the outcomes of midface surgery.

The average three-dimensional face for different sex and age groups in a Dutch population.

The increasing use of three-dimensional imaging calls for reference models representing large parts of the population. The aim of this prospective study was to create templates depicting facial maturation in the younger age groups. Healthy Dutch volunteers were captured, without selection of inclusions. Three-dimensional average faces were created using MATLAB, for both genders in four age groups (4-8 years, 8-12 years, 12-16 years, and ≥16 years). Variation within the groups was calculated and depicted on an average face with a green to red colour scale, corresponding to standard deviations between 0 and ≥ 3 mm, respectively. Measurements of the distances of eight peri-oral landmarks were provided as ratios. The statistical analysis was performed using ANOVA and Tukey's test. Three-dimensional reconstructions of the average face and their first principal component were created for each gender and age group. The first principal component comprised the facial width for each group, and the variation of landmarks was low. All ratios showed an increasing trend with increasing age, except for the ratio of philtrum width to mouth width. This study is novel in comparing facial morphology by means of ratios and in creating average faces for the different young age groups. These data provide useful insights into facial maturation, which might be beneficial for facial surgeons.

The surgical anatomy of a (robot-assisted) minimally invasive transcervical esophagectomy.

BACKGROUND: Transcervical esophagectomy allows for esophagectomy through transcervical access and bypasses the thoracic cavity, thereby eliminating single lung ventilation. A challenging surgical approach demands thorough understanding of the encountered anatomy. This study aims to provide a comprehensive overview of surgical anatomy encountered during the (robot-assisted) minimally invasive transcervical esophagectomy (RACE and MICE). METHODS: To assess the surgical anatomy of the lower neck and mediastinum, MR images were made of a body donor after, which it was sliced at 24-µm intervals with a cryomacrotome. Images were made every 3 slices resulting in 3.200 images of which a digital 3D multiplanar reconstruction was made. For macroscopic verification, microscopic slices were made and stained every 5 mm (Mallory-Cason). Schematic drawings were made of the 3D reconstruction to demonstrate the course of essential anatomical structures in the operation field and identify anatomical landmarks. RESULTS: Surgical anatomy 'boxes' of three levels (superior thoracic aperture, upper mediastinum, subcarinal) were created. Four landmarks were identified: (i) the course of the thoracic duct in the mediastinum; (ii) the course of the left recurrent laryngeal nerve; (iii) the crossing of the azygos vein right and dorsal of the esophagus; and (iv) the position of the aortic arch, the pulmonary arteries, and veins. CONCLUSIONS: The presented 3D reconstruction of unmanipulated human anatomy and schematic 3D 'boxes' provide a comprehensive overview of the surgical anatomy during the RACE or MICE. Our findings provide a useful tool to aid surgeons in learning the complex anatomy of the mediastinum and the exploration of new surgical approaches such as the RACE or MICE.

Surgical techniques in restoration lumbar lordosis: a biomechanical human cadaveric study.

PURPOSE: Degenerative changes of the lumbar spine lead in general to decrease of lumbar lordosis (LL). This change affects the overall balance of the spine, and when surgery is deemed, necessary restoration of the LL is considered. How this restoration can be achieved is a matter of controversy. The main purpose of this cadaveric study was to investigate the different steps of common posterior surgical techniques to understand the contribution of each successive step in restoring LL. METHODS: Ten fresh-frozen human lumbar spine specimens were used to perform a sequential correction and instrumentation with a pedicle screw construct. RESULTS: The mean LL angle measured at L3-L4 in intact condition was 12.9°; after screw insertion and compression, this increased to 13.8° (+ 7%, p = 0.04), after bilateral facetectomy to 16.3° (+ 20%, p = 0.005), after discectomy and insertion of interbody cage to 18.0º (+ 9%, p = 0.012), after resection of the lamina and the processes spinosus to 19.8° (+ 10%, p = 0.017), and after resection of the anterior longitudinal ligament to 25.4° (+ 22%, p = 0.005). CONCLUSIONS: Each step contributed statistically significant to restoration of segmental lordosis with bilateral facetectomy contributing the most in terms of percentage. LEVEL OF EVIDENCE: IV.

Correction of the pelvic incidence using a bilateral extending pelvic osteotomy: a proof of concept study.

INTRODUCTION: The aim of this proof of concept human cadaver study was to quantify the effect of a bilateral extending pelvic osteotomy (BEPO) on pelvic incidence (PI) as a potential alternative for a pedicle subtraction osteotomy (PSO) in patients with severe spinal sagittal malalignment. MATERIALS AND METHODS: 10 fresh frozen human cadavers were treated with the BEPO technique. CT images were made before and after the osteotomy and pure sagittal images were created on which PI was measured. RESULTS: The mean pre-osteotomy PI was 47.9° (range 36.4-63.9) and the mean post-osteotomy PI was 36.5° (range 22.1-54.4). The mean correction was - 10.4° with a range of - 8.4° to - 17.3° (p = 0.03), which resulted in a mean decrease of 23% in the PI (range 16-42). CONCLUSIONS: There was a feasible and effective correction of PI using the BEPO technique on the os ilium. This was a preliminary cadaveric study. No conclusions could be made on global sagittal alignment. We postulate that an extending osteotomy of the ilium could be a potential alternative for a PSO reducing the complexity of spine surgery in patients with severe spinal sagittal malalignment.

New insights into tip supporting structures. Consequences for nasal surgery.

BACKGROUND: Knowledge of tip supporting structures is crucial for successful rhinoplastic surgery. The aim of this study was to provide detailed anatomical and histological descriptions of the tip supporting structures. METHODS: Serial coronal sections of the entire external noses from seven cadavers were studied after staining by Mallory-Cason and Verhoeff-Van Gieson procedures. RESULTS AND CONCLUSIONS: We found no histological evidence of ligaments between the cartilaginous- and bony parts of the nasal skeleton, and between the skin and the nasal skeleton. Instead, we found a perichondrial-periosteal lining within the soft tissue envelope. The main tip supporting and shaping structures are: septal and lobular cartilages, premaxillae, and the soft tissue envelope including the periosteal-perichondrial envelope/membrane. These findings may have clinical relevance in functional and aesthetic rhinoplasties.

Metastatic incidence of (PET)CT positive lung hilar and retroperitoneal lymph nodes in esophageal cancer patients.

BACKGROUND: Extra-regional lymph node metastases strongly determine treatment options in patients with esophageal cancer. Staging modalities such as (FDG-PET) CT scanning frequently show activity in retroperitoneal and lung hilar lymph nodes. This study evaluated the incidence of histologically confirmed metastases, treatment approach and recurrence patterns in patients with (FDG-PET) CT positivity in these regions. METHODS: All patients with (FDG-PET-) CT positive hilar and/or retroperitoneal lymph nodes at primary staging or restaging discussed at a multidisciplinary tumor board meeting for staging of esophageal cancer between January 2012-December 2017 were included. Biopsies and follow-up were evaluated to determine the presence of metastases and progression rates. RESULTS: From 2012 to 2017, 65 of 857 patients (7.6%) were selected with positive retroperitoneal and/or hilar lymph nodes. A total of 47/65 (72.3%) patients had positive retroperitoneal lymph nodes, which contained metastases in 19 (29.2%). When no biopsy was performed and curative treatment was given (n = 14), 9 patients had progression or locoregional and distant recurrence. Positive hilar lymph nodes were identified in 21 (32.3%) patients; 4 were biopsied and none contained metastases. In these patients no recurrence of disease was seen during follow-up. CONCLUSIONS: The majority of biopsied (PET)CT-positive retroperitoneal lymph nodes at staging contained metastases, while biopsied (PET)CT-positive hilar nodes did not. Histological evaluation of (PET)CT -positive retroperitoneal lymph nodes at staging imaging is recommended, while based on this small series, (PET)CT-positive hilar lymph nodes most likely represent reactive lymphadenopathy.

Author Correction: Rapid and Precise Semi-Automatic Axon Quantification in Human Peripheral Nerves.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Rapid and Precise Semi-Automatic Axon Quantification in Human Peripheral Nerves.

We developed a time-efficient semi-automated axon quantification method using freeware in human cranial nerve sections stained with paraphenylenediamine (PPD). It was used to analyze a total of 1238 facial and masseteric nerve biopsies. The technique was validated by comparing manual and semi-automated quantification of 129 (10.4%) randomly selected biopsies. The software-based method demonstrated a sensitivity of 94% and a specificity of 87%. Semi-automatic axon counting was significantly faster (p < 0.001) than manual counting. It took 1 hour and 47 minutes for all 129 biopsies (averaging 50 sec per biopsy, 0.04 seconds per axon). The counting process is automatic and does not need to be supervised. Manual counting took 21 hours and 6 minutes in total (average 9 minutes and 49 seconds per biopsy, 0.52 seconds per axon). Our method showed a linear correlation to the manual counts (R = 0.944 Spearman rho). Attempts have been made by several research groups to automate axonal load quantification. These methods often require specific hard- and software and are therefore only accessible to a few specialized laboratories. Our semi-automated axon quantification is precise, reliable and time-sparing using publicly available software and should be useful for an effective axon quantification in various human peripheral nerves.

Effect of vagus nerve stimulation on tissue damage and function loss in a mouse myocardial ischemia-reperfusion model.

OBJECTIVES: In cardiac ischemia, acute inflammatory responses further increase the detrimental effect on myocardial tissue. Since vagus nerve stimulation (VS) attenuates inflammatory responsiveness this study examines the effect of VS on myocardial damage development in a cardiac ischemia-reperfusion (IR) mouse model. METHODS: 54 male C57Bl/6j mice were subjected to an IR procedure with or without prior VS. The effects on inflammatory responsiveness, infarct size, cardiac function, neutrophils, lymphocytes and vascular endothelial growth factor (VEGF) in the infarcted myocardium were measured at 48 h after intervention. Group results were compared with unpaired Mann-Whitney or Kruskall-Wallis test. RESULTS: A significant decrease in inflammatory responsiveness was not verified by decreased TNFα levels in blood from VS and IR treated mice. The percentage infarct size over area at risk was smaller in the group with VS + IR compared with IR (22.4 ±â€¯10.2% vs 37.6 ±â€¯9.0%, p = 0.003). The degree of the reduction in cardiac function was not different between the IR groups with or without VS and no group differences were found in amounts of neutrophils, CD3+ lymphocytes and VEGF in the reperfused mouse heart. CONCLUSION: The present study does not provide clear evidence of a reducing role for VS on cardiac function loss. This could mean that VS has a less inhibiting effect on myocardial inflammation than may be expected from the literature.

A rapid and simple method for visualizing milky spots in large fixed tissue samples of the human greater omentum.

Milky spots are unique lymphoid structures in the greater omentum that participate in both immune homeostasis of the peritoneal cavity and formation of omental metastases. We developed a rapid and simple staining method to enable macro- or stereomicroscopic identification of these miniscule structures in large samples of fixed human greater omentum. By immersing approximately 6 × 4 cm samples of omental tissue in hematoxylin, these samples could be evaluated quickly for the presence of milky spots. We used an alum hematoxylin variant containing 1 g hematoxylin, 50 g aluminium ammonium sulfate, 0.2 g sodium iodide, 1 g citric acid and 50 g chloral hydrate. This staining method enabled us to determine the number, location, dimensions and topographical relation of milky spots to other structures. Our method also facilitates isolation of milky spots for further investigation. Hematoxylin imparts a blue color to the milky spots, which remains in place during further processing for paraffin embedding. This enabled easy recognition of milky spots during transfer through various solutions and permitted selection of relevant paraffin slides prior to additional staining.

Effect of bilateral carotid occlusion on cerebral hemodynamics and perivascular innervation: An experimental rat model.

We aimed to investigate the effect of chronic cerebral hypoperfusion on cerebral hemodynamics and perivascular nerve density in a rat model. Bilateral common carotid artery (CCA) ligation (n = 24) or sham-operation (n = 24) was performed with a 1-week interval. A subgroup (ligated n = 6; sham-operated n = 3) underwent magnetic resonance imaging (MRI) before the procedures and 2 and 4 weeks after the second procedure. After termination, carotids were harvested for assessment of complete ligation and nerve density in cerebral arteries that were stained for the general neural marker PGP 9.5 and sympathetic marker TH by computerized image analysis. Five rats were excluded because of incomplete ligation. MRI-based tortuosity of the posterior communicating artery (Pcom), first part of the posterior cerebral artery (P1) and basilar artery was observed in the ligated group, as well as an increased volume (p = 0.05) and relative signal intensity in the basilar artery (p = 0.04; sham-group unchanged). Immunohistochemical analysis revealed that compared to sham-operated rats, ligated rats had increased diameters of all intracircular segments and the extracircular part of the internal carotid artery (p < 0.05). Ligated rats showed a higher general nerve density compared to controls in P1 (10%, IQR:8.7-10.5 vs. 6.6%, IQR:5.5-7.4, p = 0.003) and Pcom segments (6.4%, IQR:5.8-6.5 vs. 3.2%, IQR:2.4-4.3, p = 0.003) and higher sympathetic nerve density in Pcom segments (3.7%, IQR:2.8-4.8 vs. 1.7%, IQR:1.3-2.2, p = 0.02). Bilateral CCA occlusion resulted in redistribution of blood flow to posteriorly located cerebral arteries with remarkable changes in morphology and perivascular nerve density, suggesting a functional role for perivascular nerves in cerebral autoregulation.

ypT0N+ status in oesophageal cancer patients: Location of residual metastatic lymph nodes with regard to the neoadjuvant radiation field.

INTRODUCTION: A subset of oesophageal cancer patients has residual nodal disease despite complete pathologic response of the primary tumour after neoadjuvant chemoradiation and resection. The aim of this study was to determine the exact location of metastatic nodes with regard to the neoadjuvant radiation field and to assess progression-free (PFS) and overall survival (OS) in this group of patients. MATERIALS AND METHODS: From January 2010 to January 2017, complete tumour responders (ypT0) after neoadjuvant chemoradiotherapy and oesophagectomy were identified from a prospective database and grouped according to residual nodal disease (ypT0N + or ypT0N0). Radiation fields were analysed for location of the metastatic nodes and PFS and OS were determined. RESULTS: In a total of 192 patients, 53 complete responders (ypT0) were identified. Of those, 11 patients (20.8%) were ypT0N+ with a total of 12 metastatic nodes: 8 (66.7%) located within the neoadjuvant radiation field and 4 (33.3%) located outside this field. Although not statistically significant, 1- and 2-year PFS were worse in ypT0N + patients (ypT0N+ 64.3% vs. ypT0N0 84.4%; ypT0N+ 48.2% vs. ypT0N0 80.7%, respectively; p = 0.051), just as 1- and 2-year OS rates, however, to a lesser extent (ypT0N+ 75.0% vs. ypT0N0 76.3%; ypT0N+ 75.0% vs. ypT0N0 72.9%, respectively; p = 0.956). CONCLUSION: Most ypT0N + lymph nodes are located within the neoadjuvant radiation field. Although a small heterogeneous population was included, this might be due to an inadequate response to neoadjuvant chemoradiotherapy leading to a trend towards worse PFS and OS in ypT0N + patients. Larger studies need to validate our findings.

Perfusion maintains functional potential in denervated mimic muscles in early persistent facial paralysis which requires early microsurgical treatment - the histoanatomic basis of the extratemporal facial nerve trunk assessing axonal load in the context of possible nerve transfers.

BACKGROUND AND OBJECTIVES: Early persistent facial paralysis is characterized by intact muscles of facial expression through maintained perfusion but lacking nerve supply. In facial reanimation procedures aiming at restoration of facial tone and dynamics, neurotization through a donor nerve is performed. Critical for reanimating target muscles is axonal capacity of both donor and recipient nerves. In cases of complete paralysis, the proximal stump of the extratemporal facial nerve trunk may be selected as a recipient site for coaptation. To further clarify the histological basis of this facial reanimation procedure we conducted a human cadaver study examining macro and micro anatomical features of the facial nerve trunk including its axonal capacity in human cadavers. Axonal loads, morphology and morbidity of different donor nerves are discussed reviewing literature in context of nerve transfers. METHODS: From 6/2015 to 9/2016 in a group of 53 fresh frozen cadavers a total of 106 facial halves were dissected. Biopsies of the extratemporal facial nerve trunk (FN) were obtained at 1 cm distal to the stylomastoid foramen. After histological processing and digitalization of 99 specimens available, 97 were selected eligible for fascicle counts and 87 fulfilled quality criteria for a semi-automated computer-based axon quantification software using ImageJ/Fiji. RESULTS: An average of 3.82 fascicles (range, 1 to 9) were noted (n = 97). 6684±1884 axons (range, 2655- 12457) were counted for the entire group (n = 87). Right facial halves showed 6364±1904 axons (n = 43). Left facial halves demonstrated 6996±1833 axons (n = 44) with no significant difference (p = 0.73). Female cadavers featured 6247±2230 (n = 22), male showed 6769±1809 axons (n = 40). No statistical difference was seen between genders (p = 0.59). A comparison with different studies in literature is made. The nerve diameter in 82 of our specimens could be measured at 1933±424 µm (range, 975 to 3012). CONCLUSIONS: No donor nerve has been described to match axonal load or fascicle number of the extratemporal facial nerve main trunk. However, the masseteric nerve may be coapted for neurotization of facial muscles with a low complication rate and good clinical outcomes. Nerve transfer is indicated from 6 months after onset of facial paralysis if no recovery of facial nerve function is seen.

Detection of titanium particles in human liver and spleen and possible health implications.

BACKGROUND: Titanium dioxide (TiO2) is produced at high volumes and applied in many consumer and food products. Recent toxicokinetic modelling indicated the potential of TiO2 to accumulate in human liver and spleen upon daily oral exposure, which is not routinely investigated in chronic animal studies. A health risk from nanosized TiO2 particle consumption could not be excluded then. RESULTS: Here we show the first quantification of both total titanium (Ti) and TiO2 particles in 15 post-mortem human livers and spleens. These low-level analyses were enabled by the use of fully validated (single particle) inductively coupled plasma high resolution mass spectrometry ((sp)ICP-HRMS) detection methods for total Ti and TiO2 particles. The presence of TiO2 in the particles in tissues was confirmed by Scanning Electron Microscopy with energy dispersive X-ray spectrometry. CONCLUSIONS: These results prove that TiO2 particles are present in human liver and spleen, with ≥24% of nanosize (< 100 nm). The levels are below the doses regarded as safe in animals, but half are above the dose that is deemed safe for liver damage in humans when taking into account several commonly applied uncertainty factors. With these new and unique human data, we remain with the conclusion that health risks due to oral exposure to TiO2 cannot be excluded.

The nerve supply of zygomaticus major: Variability and distinguishing zygomatic from buccal facial nerve branches.

The zygomaticus major (ZM) is important for the human smile. There are conflicting data about whether the zygomatic or buccal branches of the facial nerve are responsible for its motor innervation. The literature provides no precise distinction of the transition zone between these two branch systems. In this study, a definition to distinguish the facial nerve branches at the level of the body of the zygoma is proposed. In the light of this definition, we conducted an anatomical study to determine how the source of innervation of the ZM was distributed. A total of 96 fresh-frozen cadaveric facial halves were dissected under loupe magnification. A hemiparotidectomy was followed by antegrade microsurgical dissection. Any branch topographically lying superficial to the zygoma or touching it was classed as zygomatic, and any neighboring inferior branch was considered buccal. The arborization of the facial nerve was diffuse in all cases. In 64 out of 96 specimens (67%, 95% CI: 56% to 76%), zygomatic branches innervated the ZM. Buccal branches innervated ZM in the other 32 facial halves (33%, 95% CI: 24% to 44%). There were no differences in respect of sex or facial side. All facial halves displayed additional branches, which crossed the muscle on its inner surface without supplying it. In 31 specimens, a nerve branch ran superficial to ZM in its cranial third. According to our classification, the zygomaticus major is innervated by zygomatic branches in 67% of cases and by buccal branches in 33%. Clin. Anat. 31:560-565, 2018. © 2018 Wiley Periodicals, Inc.

Functional anatomy of the nasal bones and adjacent structures. Consequences for nasal surgery.

The periosteum of the nasal bones, the periosteal-perichondrial nasal envelope, and the cartilaginous support of the bony vault were studied in serial coronal sections of four human cadaver noses. To differentiate between the various tissue components, the sections were stained according to Mallory-Cason and Verhoeff-Van Gieson stain. The results demonstrated: 1. the presence of clearly distinguishable layers of the periosteum covering the nasal bones; 2. the presence of a continuous periosteal-perichondrial covering of the bony and cartilaginous nasal vaults; 3. the way the cartilaginous support of the bony vault is constructed. The findings described in the present study may have clinical relevance in nasal surgery.

The peri-esophageal connective tissue layers and related compartments: visualization by histology and magnetic resonance imaging.

An organized layer of connective tissue coursing from aorta to esophagus was recently discovered in the mediastinum. The relations with other peri-esophageal fascias have not been described and it is unclear whether this layer can be visualized by non-invasive imaging. This study aimed to provide a comprehensive description of the peri-esophageal fascias and determine whether the connective tissue layer between aorta and esophagus can be visualized by magnetic resonance imaging (MRI). First, T2-weighted MRI scanning of the thoracic region of a human cadaver was performed, followed by histological examination of transverse sections of the peri-esophageal tissue between the thyroid gland and the diaphragm. Secondly, pretreatment motion-triggered MRI scans were prospectively obtained from 34 patients with esophageal cancer and independently assessed by two radiologists for the presence and location of the connective tissue layer coursing from aorta to esophagus. A layer of connective tissue coursing from the anterior aspect of the descending aorta to the left lateral aspect of the esophagus, with a thin extension coursing to the right pleural reflection, was visualized ex vivo in the cadaver on MR images, macroscopic tissue sections, and after histologic staining, as well as on in vivo MR images. The layer connecting esophagus and aorta was named 'aorto-esophageal ligament' and the layer connecting aorta to the right pleural reflection 'aorto-pleural ligament'. These connective tissue layers divides the posterior mediastinum in an anterior compartment containing the esophagus, (carinal) lymph nodes and vagus nerve, and a posterior compartment, containing the azygos vein, thoracic duct and occasionally lymph nodes. The anterior compartment was named 'peri-esophageal compartment' and the posterior compartment 'para-aortic compartment'. The connective tissue layers superior to the aortic arch and at the diaphragm corresponded with the currently available anatomic descriptions. This study confirms the existence of the previously described connective tissue layer coursing from aorta to esophagus, challenging the long-standing paradigm that no such structure exists. A comprehensive, detailed description of the peri-esophageal fascias is provided and, furthermore, it is shown that the connective tissue layer coursing from aorta to esophagus can be visualized in vivo by MRI.

Periosteal vascularization of the distal femur in relation to distal femoral osteotomies: a cadaveric study.

BACKGROUND: The purpose of this study was to investigate periosteal vessels location as intra-operative landmarks in distal femoral osteotomies and focused on the branching pattern of the vascular supply of the medial and lateral femoral condyle, its constancy, and the relationship to the height of distal femoral osteotomies. Anastomoses of relevant vessels were studied to analyze the risk of vascular insufficiency after transection of landmark vessels. METHODS: A human cadaver dissection study on the vascular supply of the medial and lateral side of the distal femur was conducted. Surgical dissection was performed in eight knees in total. Distances between the vascular supply and bony landmarks were calculated. Relation of the vascular structures to the transverse bone cuts of distal femoral osteotomies was described, as well as anastomoses of relevant vessels. RESULTS: On the medial side of the distal femur the periosteum was primarily supplied by the descending genicular artery (DGA) in 87.5 % of the specimens. In the absence of the DGA, the superior medial genicular artery was the supplier. Vascularization took place through two constant branches, the upper transverse artery (UTA) and the central longitudinal artery. The UTA originated at a mean distance of 6.9 cm (range 5.9-7.9 cm) above the knee joint line. On the lateral side of the distal femur the superior lateral genicular artery was the main vessel. In all dissected knees it gave off the lateral transverse artery (LTA). The LTA originated at a mean distance of 6.9 cm (range 5.8-7.6 cm) above the knee joint line. Anastomoses between the UTA, LTA and the longitudinal arch of the femoral shaft were found that could prevent vascular insufficiencies after transection of the UTA and LTA. CONCLUSIONS: The vascular supply of the medial and lateral aspects of the femoral condyle is highly constant. Both the UTA, on the medial side, and the LTA, on the lateral side, can serve as a landmark for orthopedic surgeons in determining the height of the osteotomy cuts in distal femoral osteotomies. Transection of these landmark vessels during the osteotomy will not result in vascular insufficiency because of a collateral supply.

Understanding the surgical pitfalls in total mesorectal excision: Investigating the histology of the perirectal fascia and the pelvic autonomic nerves.

AIM: Excellent understanding of fasciae and nerves surrounding the rectum is necessary for total mesorectal excision (TME). However, fasciae anterolateral to the rectum and surrounding the low rectum are still poorly understood. We studied the perirectal fascia enfolding the extraperitoneally located part of the rectum in en-bloc cadaveric specimens and the University Medical Center Utrecht (UMCU) pelvic dataset, and describe implications for TME. METHODS: Four donated human adult cadaveric specimens (two males, two females) were obtained through the Leeds GIFT Research Tissue Programme. Paraffin-embedded blocks were produced and serially sectioned at 50 and 250 µm intervals. Whole mount sections were stained with haematoxylin & eosin, Masson's trichrome and Millers' elastin. Additionally, the UMCU pelvic dataset including digitalised cryosections of a female pelvis in three axes was studied. RESULTS: The mid and lower rectum were surrounded by a multi-layered perirectal fascia, of which the mesorectal fascia (MRF) and parietal fascia bordered the 'holy plane'. There was no extra constant fascia forming a potential surgical plane. Nerves ran laterally to the MRF. More caudally, the mesorectal fat strongly reduced and the MRF approached the rectal muscularis propria. The MRF had a variable appearance in terms of thickness and completeness, most prominently at the anterolateral lower rectum. CONCLUSION: Dissection onto the MRF allows nerve preservation in TME. Rectal surgeons are challenged in doing so as the MRF varies in thickness and shows gaps, most prominently at the anterolateral lower rectum. At this site, the risk of entering the mesorectum is great and may result in an incomplete specimen.