Main Blood Supply Research Articles

Preoperative transarterial embolization of a recurrent orbital solitary fibrous tumor with significant hypervascularity: a case report

BackgroundOrbital solitary fibrous tumors (SFTs) are rare neoplasms. Recurrent, hypervascular, malignant variations of orbital SFTs have recently been noted and can present a surgical challenge.Case presentationWe describe a case of a 53-year-old Chinese woman with a history of a resected orbital SFT. She presented with proptosis, limited eyeball movement, and visual loss in the right eye, suggestive of a recurrent SFT. Ocular examination with multimodal imaging revealed a large, nonpulsatile, noncompressible, hypervascular mass behind the eyeball. The patient underwent preoperative transarterial embolization of the main blood supply to the tumor in order to control intraoperative blood loss, followed by ocular enucleation to optimize exposure and enable complete resection of the tumor. Embolization of the right ophthalmic artery and the distal branch of the right internal maxillary artery caused an immediate, substantial reduction of vascular flow, which allowed us to enucleate the eyeball and resect the tumor with minimal blood loss and no complications.ConclusionsOur case is so far the first Chinese case of successful preoperative embolization of the main blood supply to a large, recurrent, hypervascular orbital SFT. This case also described a different surgical approach to achieve total removal of an orbital SFT without osteotomy.

The topographic and systematic anatomy of the alpaca stomach.

The gastric anatomy of the alpaca (Vicugna pacos) is adapted to the physiological process of ruminating and the degradation of plant cell wall contents to a great extent. Most alpaca husbandries consist of only few animals and with the still increasing number of alpacas worldwide the number of persons who are responsible for these animals is increasing as well. Despite this, little research has been done with regard to the clinical anatomy of the stomach of alpacas. Six animals were used for dissection. The vascular system of two alpacas was injected with latex milk to illustrate the course of the blood supply to the viscera. One stomach was used to prepare formalin-fixed preparations. The stomach consisted of three compartments (C1-C3) and showed two sacculated areas in C1 and another comb-like system in C2. The compartments were lined by a smooth mucosa. Only the deep cells of C2 were lined by a papillated mucosa. The main blood supply was provided by the coeliac artery which was divided into the hepatic artery and the left gastric artery, supplying abdominal organs like liver, spleen, pancreas, and the initial part of the duodenum. Literature research on the llama stomach showed that the alpaca stomachs that were used resembled each other to a very large degree. The specific design of the stomach together with its related functions and physiological processes confirm that the evolution of Tylopoda and Ruminantia took place in parallel and not in homology.

Fetus in fetu: two case reports from North African country

BackgroundFetus in fetu is a rare congenital anomaly. The exact etiology is unclear; one of the mostly accepted theories is the occurrence of an embryological insult occurring in a diamniotic monochorionic twin leading to asymmetrical division of the blastocyst mass. Commonly, they present in the infancy with clinical picture related to their mass effect. About 80% of cases are in the abdomen retroperitoneally.Case presentationWe present two cases of this rare condition. The first case was for a 10-year-old girl that presented with anemia and abdominal mass, while the second case was for a 4-month-old boy that was diagnosed antenatally by ultrasound. Both cases had vertebrae, recognizable fetal organs, and skin coverage. Both had a distinct sac. The second case had a vascular connection with the host arising from the superior mesenteric artery. Both cases were intra-abdominal and showed normal levels of alpha-fetoprotein. Histopathological examination revealed elements from the three germ layers without any evidence of immature cells ruling out teratoma as a differential diagnosis.ConclusionsOwing to its rarity, fetus in fetu requires a high degree of suspicion and meticulous surgical techniques to avoid either injury of the adjacent vital structures or bleeding from the main blood supply connection to the host. It should be differentiated from mature teratoma.

Macroscopical Anatomy and Radiographic Study of the Non-Lactating Udder of Adult Local Iraqi Cow (Bos taurus)

The purpose of this study was to describe some anatomical and radiological features of the non-lactating udder of adult local Iraqi cow. Eight udder of local breed cow clinically appeared healthy and aged between 2-5 years were obtained from a local slaughterhouse located at Baghdad province. Five udders were used for anatomical study and the rest 3 udders were used for the radiological study. The study primed to describe the macroscopic anatomy of the udder and investigate the udder’s normal blood supply using red-colored latex. The mammography method was to describe the duct system of the glandular tissue of the mammary gland which was performed using the iodine compound and barium sulphate as contrast media. The results showed that the udder was located in the inguinal region and covered by pigmented skin with fine hair and composed of four quarters. Each quarter has one teat which was long, cylindrical in shape, opened with one orifice; and internally has longitudinal folds in its mucous membrane. The blood supply of udder by the external pudendal arteries (left and right) branched into cranial and caudal mammary ones. The radiological study showed that the glandular tissue of udder was composed of complex ducal system which included the teat canal (long narrow), teat sinus (spindle-shaped cavity), lactiferous sinus (large round structure), lactiferous ducts, cistern ducts, interlobular duct, intralobular duct and alveoli (round sac like).In conclusion, this study is considered as an important contribution of describing the anatomical features, main blood supply and a pathway of the intraglandular duct system of the non-lactating udder in local cow breed which is necessary for surgical operations in several cases of the udder.

Arterial branching pattern of the rabbit femoral artery.

Rabbits have highly developed hindlimb muscles, whereas their bones are fragile, thus resulting in frequent hindlimb fractures. To repair these fractures, it is important to understand the arterial branching pattern of the femoral artery, as it provides the main blood supply to the hindlimb. Since the descriptions from prior studies are insufficient, the aim of the present study was to determine the detailed arterial branching pattern of the rabbit femoral artery. Therefore, to address this issue, we examined 30 male and 20 female New Zealand White rabbits after colored latex injections into the femoral artery. Results showed that the femoral artery gave rise to the pudendoepigastric trunk, along with the deep femoral, lateral circumflex femoral, superficial caudal epigastric, saphenous, descending genicular, and proximal and middle caudal femoral arteries, in conjunction with frequent individual variations. In all the observed halves, the last branch from the femoral artery was the distal caudal femoral artery. Individual variations in the branching pattern of these arteries occurred independently in the proximal and the distal portions of the femoral artery, and they were, respectively, categorized into four and three major types based on the number of the branching levels along the proximodistal axis of the femoral artery. The individual variations in the arterial branching pattern of the rabbit femoral artery that were demonstrated in the present study may provide an important anatomical basis for refining the orthopedic surgical procedure in the rabbit.

A Right Accessory Vertebral Artery and Variation in the Origin and its Entry to the Transverse Foramen

Variations of the vertebral artery origin are congenital abnormalities that occur during embryonic development. The vertebral artery origins from the superior part of the first part of the subclavian artery and it provides the main blood supply of the posterior cranial fossa structures. Several variations in the vertebral artery origin and its entry to the transverse foramen have been reported in advance. However, mention to the variation of the right vertebral artery origin and its entrance to the transverse foramen is rare. By describing dissection of an old man cadaver, two vertebral arteries were observed which were arised from the first part of the subclavian artery at the right side, and they follow a different direction to enter the transverse foramen. One of the arteries rises in its natural direction and enters into the transverse foramen of C6, and the other arteries take an abnormal direction upwards and then enter the higher level surface into the transverse foramen of C4. It is necessary to mention, the artery on the left was in its normal state. Regarding neck root surgery, knowing these variations reduces arterial injury during surgery and angiography.

Hemodynamic Data Assimilation in a\xa0Subject-specific Circle of Willis Geometry

PurposeThe anatomy of the circle of Willis (CoW), the brain’s main arterial blood supply system, strongly differs between individuals, resulting in highly variable flow fields and intracranial vascularization patterns. To predict subject-specific hemodynamics with high certainty, we propose a data assimilation (DA) approach that merges fully 4D phase-contrast magnetic resonance imaging (PC-MRI) data with a numerical model in the form of computational fluid dynamics (CFD) simulations.MethodsTo the best of our knowledge, this study is the first to provide a transient state estimate for the three-dimensional velocity field in a subject-specific CoW geometry using DA. High-resolution velocity state estimates are obtained using the local ensemble transform Kalman filter (LETKF).ResultsQuantitative evaluation shows a considerable reduction (up to 90%) in the uncertainty of the velocity field state estimate after the data assimilation step. Velocity values in vessel areas that are below the resolution of the PC-MRI data (e.g., in posterior communicating arteries) are provided. Furthermore, the uncertainty of the analysis-based wall shear stress distribution is reduced by a factor of 2 for the data assimilation approach when compared to the CFD model alone.ConclusionThis study demonstrates the potential of data assimilation to provide detailed information on vascular flow, and to reduce the uncertainty in such estimates by combining various sources of data in a statistically appropriate fashion.

Arterial blood supply of the ostrich (struthio camelus) heart

The current work was focused on giving a full morphological description of the arterial supply of the heart of the ostrich (struthio camelus). The purpose of this work is achieved on eight ostrich hearts. The arterial blood supply of the ostrich heart occurred through the two coronary arteries that originated from the aorta at the left and right aortic sinus. Each coronary artery gave off a deep and a superficial branch. The main arterial blood supply of the ostrich heart came from the superficial branches of the both coronary arteries, while the deep branches of the two coronary arteries were relatively small and originated to supply only the interventricular septum, called the septal branches. The left interatrial branch was the first branch originated from the left coronary artery and originated closely to the origin of the left coronary artery. The superficial branch gave off a conal branch, circumflex branch and continued as an interventricular branch. The interventricular branch gave off an angular branch, ventricular branches, septal branches and terminated by two terminal branches. The circumflex branch gave off ventricular branches and atrial branches. The interventricular septum was mainly supplied by the deep branch of both the right and left coronary artery and also there were a septal supply from the septal branches of both paraconal and subsinosal interventricular artery. There were a numerous homo and intercoronary anastomosis at the cardiac apex.

Arterial Blood Supply and Angiography of the Fore Foot in One- Humped Camel (Camelus dromederius)

The present study was conducted on eight fresh forelimbs to investigate a detailed anatomical description of the arterial blood supply in adult dromedary camel’s foot. Anatomical and angiographic techniques were used in order to give detailed data about the origin and pattern of distribution of these arteries. Moreover, this data serve other researchers in comparison with different animals. The specimens injected with red colored gum milk latex for anatomical dissection and urograffin injection for angiographic purposes throughout the median artery. The main arterial blood supply of camel’s digit was derived from common palmar digital artery, palmar metacarpal artery, in addition to smaller branches detached from the dorsal metacarpal artery.

Modern neurogenetic representations of MELAS syndrome. Clinical cases (the lecture)

This lecture with a description of clinical cases presents information on such a mitochondrial disease from the group of hereditary metabolic diseases, like MELAS syndrome (OMIM: 540000). The main manifestations of this progressive disease are stroke-like episodes and a specific form of encephalopathy, including epileptic seizures with the presence of a phenomenon of "ragged red fibers" and early dementia. Clinical cases, given in this lecture, supplement the piggy bank of genetically verified mitochondrial diseases leading to the development of polymorphic neurological disorders and characteristic neuroimaging picture, namely the appearance of polymorphic ischemic changes in the temporal, parietal or occipital regions of the brain, that do not correspond to the zones of the main vascular blood supply, as the basis for the formation of such focus is the phenomenon of mitochondrial angiopathy, and not thrombosis. The description of clinical cases reflects our own observations and the main steps in the diagnosis of this severe hereditary disease, taking into account of the latest neurogenetic representations. In addition to the data given in the clinical course of the disease, the results of the genetic interpretation of the MELAS syndrome are given; modern methods of diagnosis and therapy are considered.

Anatomy of pisiform blood supply and feasibility of vascularized pisiform transfer for avascular necrosis of lunate based on digital technique

To provide anatomical basis for vascularized pisiform transfer in the treatment of advanced avascular necrosis of the lunate (Kienböck's disease) by studying its morphology and blood supply pattern based on digital technique. Twelve adult fresh wrist joint specimens were selected and treated with gelatin-lead oxide solution from ulnar or radial artery. Then the three-dimensional (3D) images of the pisiform and lunate were reconstructed by micro-CT scanning and Mimics software. The morphologies of pisiform and lunate were observed and the longitudinal diameter, transverse diameter, and thickness of pisiform and lunate were measured. The main blood supply sources of pisiform were observed. The number, diameter, and distribution of nutrient foramina at proximal, distal, radial, and ulnar sides of pisiform were recorded. The anatomic parameters of the pedicles (branch of trunk of ulnar artery, carpal epithelial branch, descending branch of carpal epithelial branch, recurrent branch of deep palmar branch) were measured, including the outer diameter of pedicle initiation, distance of pedicle from pisiform, and distance of pedicle from lunate. There were significant differences in the longitudinal and transverse diameters between pisiform and lunate ( t=6.653, P=0.000; t=6.265, P=0.000), but there was no significant difference in thickness ( t= 1.269, P=0.109). The distal, proximal, radial, and ulnar sides of pisiform had nutrient vessels. The nutrient foramina at proximal side were significantly more than that at distal side ( P<0.05), but there was no significant difference in the diameter of nutrient foramina between different sides ( P>0.05). The outer diameter of pedicle initiation of the recurrent branch of deep palmar branch was significantly smaller than the carpal epithelial branch and descending branch of carpal epithelial branch ( P<0.05). There was no significant difference in the distance of pedicle from pisiform/lunate between branch of trunk of ulnar artery and recurrent branch of deep palmar branch ( P>0.05), and between carpal epithelial branch and descending branch of carpal epithelial branch ( P>0.05). But the differences between the other vascular pedicles were significant ( P<0.05). There are abundant nutrient vessels at the proximal and ulnar sides of pisiform, so excessive stripping of the proximal and ulnar soft tissues should be avoided during the vascularized pisiform transfer. It is feasible to treat advanced Kienböck's disease by pisiform transfer with the carpal epithelial branch of ulnar artery and the descending branch.

Study of the Anatomical Variations in the Nutrient Foramina of Fibula

Background: The main blood supply to a growing bone is through its nutrient artery. It enters the bone through nutrient foramina (NF). Fibula is commonly used as a bone graft. The anatomical location of NF on fibula is valuable during surgeries. Objective: Topographic assessment of nutrient foramina on human fibulae. Study Design: Cross Sectional Observational Study. Settings: Anatomy Department, Postgraduate Medical Institute, Lahore Pakistan. Duration: 4 months (from 1-12-2018 to 31-3-2019). Methodology: 100 fibulae were obtained from the bone bank of anatomy department, Postgraduate Medical Institute, Lahore. The number of NF and their position on the fibular shaft were observed. Results: Single foramen was observed in 90 (90%) fibulae, 4 (4%) had two foramina, while 6 (6%) had no NF. 86 (93%) foramina were seen on the middle third of the bone. 47 (50%) NF were present on the posterior aspect. 2 (2%) foramina were on the proximal third and 4 (4%) were on the distal third of the fibulae. Conclusion: The posterior aspect and the middle third of the bony shaft bore most of the nutrient foramina.

The clinical and ultrasound-based comparison between cesarean scar pregnancy and other lower uterine segment pregnancies with a history of cesarean section

Objective: To compare the clinical and ultrasound characteristics of cesarean scar pregnancy (CSP) and other lower uterine segment pregnancies (LUSPs) to enable differential diagnosis of the two pathologies in the first trimester.Methods: A retrospective analysis of early pregnancies with a gestational sac located in the lower uterine segment with cesarean section history in our hospital from December 2011 to February 2018 was performed. According to the diagnoses, the patients were divided into the CSPs group and the other LUSPs group. The clinical and ultrasound features were compared.Results: A total of 38 patients were enrolled with 16 (42.1%) CSPs and 22 (57.9%) other LUSPs. Compared to the other LUSPs group, the CSPs group had thinner lower uterine myometrium (0.16 ± 0.11 cm versus 0.32 ± 0.14 cm, p = .000), larger maximum diameter of the gestational sac (5.14 ± 2.08 cm versus 3.77 ± 1.24 cm, p = .028); the distribution of the villous chorion sites (p = .001) and the main blood supply sites (p = .000) of the gestational sac were different between the two groups. Surgical bleeding volume during the termination of gestation was higher in the CSPs group than in the other LUSPs group (p = .028).Conclusion: Patients with CSPs and other LUSPs have different imaging characteristics on ultrasound. The prognosis of these patients also differs. Ultrasound feature is very useful in the differential diagnosis of these two clinical-mimicking pathologies.

Rare variation of third dorsal metatarsal artery of the horse

The purpose of this case report is to describe and document a rare anatomical variation of the cranial and caudal tibial arteries seen in a mare. During routine dissection, a deviation of the great metatarsal artery (third dorsal metatarsal artery) of the right limb of a horse was detected. The artery was smaller than usual and localised between the third and the fourth metatarsal bone, while the main blood supply of the digit wаs recеived by the medial plantar artery. Deviation of the artery of the left limb and of the veins of both limbs was not detected. This variation of the main arterial vessel topography is important not only for anatomy but also for the evaluation of the normal pulse, inflammatory processes of the digit and the hoof, occlusion of the artery itself, as well as in performing conduction ana­esthesia and surgery in the metatarsal area of the horse.

Microscopic anatomy study of artery of auricle for auricle replantation

Objective To provide the anatomical information for auricle replantation. Methods From March, 2016 to March, 2019, a total of 25 fresh adult cadaveric head were used, 20 of these specimens were perfused with plastic and eroded to be vascular cast mold, 5 specimens perfused with red latex for anatomy, then observed the origin, course, diameter and arteries anastomose between branches of the posterior auricular artery (PAA) and superficial temporal artery (STA). Results The main blood supply to the auricle were auricle branches of PAA and STA. The auricle branches of PAA and STA both divided into superior, intermedius and inferior branches, and distributed in the auricle posterior surface and anterior surface, respectively. The auricle branches of PAA running across ear cartilage, distributed in the anterior surface, and anastomosed with auricle branches of STA. The diameters of these branches at the initiating portion were 0.2-0.8 mm. Eighty percent of blood supply to earlobe was from the inferior branches of PAA, and 20% from the STA. Conclusion The auricle branches of PAA played an important role to the auricle replantation. The auricle branches of PAA should be the firstly selected vessle in operation, and the auricle branches of STA be the second choice. Key words: Posterior auricular artery; Superficial temporal artery; Auricle replantation; Microscopic anatomy

Mandibular Nerve and Maxillary Artery Anatomical Variations: Implications for Dentistry, Maxillofacial and Oral Surgery

BACKGROUNDThe posterior division mandibular nerve (V3) gives rise to several branches in the infratemporal region, including the auriculotemporal (ATN), lingual (LN), and inferior alveolar (IAN) nerve. The IAN block is the most commonly performed local anesthetic technique used in dentistry, and atypical morphology of the IAN could lead to block failure or complications. Further, all of the V3 branches are located in close proximity to the maxillary artery, the main blood supply to the maxillofacial region, thus need to be considered and avoided during surgery.OBJECTIVEHere we present a case series derived from examination of n=12 cadavers as part of routine dissection in a gross anatomy course. We examined the infratemporal fossa of each cadaver for V3 and maxillary artery anatomical variations.RESULTSVariations in either V3 or the maxillary artery were clearly visible in 3 out of 12 cadavers. The potential clinical significance of two selected variations is summarized here: Variant 1: Just inferior to the origin of the IAN and LN from V3, we observed IAN fenestration around the second part of the maxillary artery. This variant is clinically relevant from multiple standpoints, as the position of the artery is unexpected, and therefore may be unintentionally compromised. Variant 2: Just inferior to the origin of the IAN and LN from V3, we observed an anomalous communicating branch between the IAN and LN. While we cannot ascertain the functional significance or origin of this branch, this coalescence of nerve fibers may limit the ability to “target” the nerves individually. For example, IAN block may also affect LN fibers, leading to alterations in taste and tongue sensation. CONCLUSIONVariations in the branching of V3 or maxillary artery were clearly visible in 3/12 cadavers. As such, variations were found in 25 percent of specimens; however, several of the specimens were damaged during dissection, thus the true incidence of variations could likely be higher. Further, these variations may be more common in patients than expected and need to be carefully considered in surgical procedures. Lastly, several variations described here have been previously described in the literature, thus the incidence of these specific variants may be much higher than expected.Support or Funding InformationN/AThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Clinical importance of the posterior meningeal artery: a review of the literature.

The posterior meningeal artery, which arises from the vertebral artery, is a critical artery in neurological lesions. However, a comprehensive review of the importance of the posterior meningeal artery is currently lacking. In this study, we used the PubMed database to perform a review of the literature on the posterior meningeal artery to increase our understanding of its role in vascular lesions. The posterior meningeal artery provides the main blood supply to the paramedial and medial portions of the dura covering the cerebellar convexity. The posterior meningeal artery is often involved in dural arteriovenous fistulas occurring near the posterior fossa, and the posterior meningeal artery can be the path for transarterial embolisation or a path through which to monitor the degree of dural arteriovenous fistula embolisation. In posterior circulation ischaemia and moyamoya disease, the posterior meningeal artery can form transdural anastomoses with pial arteries at the surface of the brain, and these can help prevent ischemia. The posterior meningeal artery can also develop aneurysms, most of which are traumatic pseudoaneurysms; patients should therefore be treated in a timely manner or followed up carefully in cases of rebleeding. In addition, during a craniotomy, the posterior meningeal artery should be protected intraoperatively to avoid damaging any transdural anastomosis that may be present. In addition, when the posterior meningeal artery is the main feeding artery of an intracranial tumour, that artery is a satisfactory path for preoperative embolisation. Briefly, the posterior meningeal artery is a very important artery in neurosurgery.

Large Intradural Tympanojugular Paragangliomas. A Contribution on Surgery and Management

Large intradural growth of tympanojugular paragangliomas (TJ-PGs) into the cerebellopontine angle is an infrequent condition that can determine an extensive involvement of vessels and brainstem, representing a surgical challenge. The current classifications lack accuracy for defining large intradural TJ-PGs and assessing their operability. This study aims to retrospectively reappraise the management of a large intradural TJ-PGs surgical series, discussing operability criteria, treatment strategies, and resection techniques. Over a series of 63 class D TJ-PGs operated on between 1973 and 2008, patients with large intradural tumors were retrospectively reviewed. Surgical techniques and outcomes with long-term follow-up were analyzed. Seven patients presented with large intradural tumors, ranging from 4 cm to 5.5 cm in diameter. These cases were treated either via a petro-occipital transsigmoid approach in a single-stage resection (4 patients) or via a petro-occipital approach as a second-stage surgery after a previous infratemporal fossa approach on the extradural tumor (3 patients). Complete tumor resection was obtained in 5 cases through wide removal of the petro-occipital skull base and exposure of the dural root of the tumor, which carries its main blood supply and allows preemptive hemostasis. No new postoperative cranial nerve losses were observed. The surgical procedure was aborted in 2 cases because of cerebellar edema and carotid artery tear, respectively. Large intradural TJ-PGs can be effectively surgically managed with an appropriate technique combined with relevant nonsurgical strategies. Thus, operability criteria for these lesions can be extended. To share objective experience on large intradural TJ-PGs, a redefinition of Di3 tumors is recalled.

Adaptive Anatomical Specialization of the Intestines of Alpacas Taking into Account their Original Habitat and Feeding Behaviour.

The gastrointestinal tract of the alpaca (Vicugna pacos) is most efficiently adapted to its habitat at high altitudes. Alpacas, just like ruminants, feed on hardly digestible forage. However, it has been demonstrated that the anatomy of the camelid digestive tract has developed independently of ruminants and not in homology to them. Despite a long history of domestication and an increasing number of animals worldwide, little research has been done on the intestinal anatomy of alpacas. The purpose of this study was to describe the anatomical features of the alpaca's intestines and to explain anatomical peculiarities in the context of evolutionary function and morphology. Another goal of this study was the demonstration of weaknesses of the intestinal anatomy predisposing alpacas to certain clinical presentations. Six animals were used for dissection. The basic structure of the intestines was comparable to that in ruminants. However, a number of characteristic peculiarities were found in alpacas, like the duodenal ampulla and the proximal and distal loop of the ascending colon. The jejunum and ileum, unlike those of ruminants, had their own mesentery largely separated from the ascending mesocolon. The main blood supply was provided by the cranial and caudal mesenteric artery. The particular lymph nodes were located along the branches of these two arteries. The spiral colon seemed to play a major role in intestinal digestion and water resorption. The size of the distal fermentation chamber allows the presumption that alpacas belong to the group of animals practicing a fractionated fermentation in the proximal and distal fermentation chambers. Anat Rec, 301:1840-1851, 2018. © 2018 Wiley Periodicals, Inc.

Pax6 regulation of Sox9 in the mouse retinal pigmented epithelium controls its timely differentiation and choroid vasculature development.

The synchronized differentiation of neuronal and vascular tissues is crucial for normal organ development and function, although there is limited information about the mechanisms regulating the coordinated development of these tissues. The choroid vasculature of the eye serves as the main blood supply to the metabolically active photoreceptors, and develops together with the retinal pigmented epithelium (RPE). Here, we describe a novel regulatory relationship between the RPE transcription factors Pax6 and Sox9 that controls the timing of RPE differentiation and the adjacent choroid maturation. We used a novel machine learning algorithm tool to analyze high resolution imaging of the choroid in Pax6 and Sox9 conditional mutant mice. Additional unbiased transcriptomic analyses in mutant mice and RPE cells generated from human embryonic stem cells, as well as chromatin immunoprecipitation and high-throughput analyses, revealed secreted factors that are regulated by Pax6 and Sox9. These factors might be involved in choroid development and in the pathogenesis of the common blinding disease: age-related macular degeneration (AMD).