Experimental swine models for perforator flap dissection in reconstructive microsurgery.

BACKGROUND: Perforator flaps account for a fraction of reconstructive procedures despite their growing popularity. Specific microsurgical skills are required for successful harvesting of perforator flaps, which are difficult to attain through direct operating room training. Cadaver and small animal dissection cannot simulate human perforator dissection, lacking either bleeding and vessel feedback or providing too small calibers. Thus, we have developed and refined over the last ten years five perforator flaps models in living pig, described their harvesting technique and provided evidence for their effectiveness as perforator flap training models. METHOD: CT angiography data from ten living pigs was used for detailed examination of the integument's vascular anatomy. Microsurgical techniques were used to standardize and harvest the perforator flaps in acute models. The same operator-assistant team, with no prior perforator flap harvesting experience, raised all flaps in a sequential manner, one animal per day, during a 7 weeks timespan. Porcine flaps were compared to human counterparts in terms of vessel caliber, dissection times. Immediate flap survival was measured as duration of perforator pulsation after completion of flap harvesting, measured every 10 minutes for up to two hours. RESULTS: Five perforator flaps were standardized, based on the deep cranial epigastric, thoracodorsal, lateral intercostal, cranial gluteal and dorsal cervical arteries and the operative technique was described in detail. Mean pig perforator size was 1.24±0.36 mm and mean pedicle diameter was 2.78±0.8 mm, which matched closely the human calibers for each flap. Total harvesting time increased 22.4% between the first two experiments due to a more cautious approach following the lack of perforator pulsation in all flaps in the first experimental animal. A total decrease of 44.4% harvesting time between second and last experiment was observed, as expected with all repetitive surgical procedures. Post-operative perforator pulsation time revealed a steep learning curve, with no or short-term pulsatile perforators in the first five pigs, followed by a 275% increase in total perforator pulsation time between 5th and 6th experimental animal. Based on these findings we provide a description of the most common mistakes, their consequences and gestures which can be trained using the pig perforator flaps, in order to overcome these mistakes. CONCLUSION: These five pig perforator flap models provide a fast and efficient learning tool to develop perforator flap harvesting skills safely. Surgical training using these five experimental models offers a similar hands-on perforator flap dissection experience as with human tissue, based on the similar sized calibers of both perforators and pedicles with their human counterparts.

Chronic Hindlimb Ischemia Assessment; Quantitative Evaluation Using Laser Doppler in a Rodent Model of Surgically Induced Peripheral Arterial Occlusion.

Therapeutic neoangiogenesis (TNA) holds promise as a treatment for peripheral arterial disease. Nevertheless, proper tools for in vivo pre-clinical investigation of different TNA approaches and their effects are still lacking. Here we describe a chronic ischemic hindlimb model in rats using laser Doppler quantitative evaluation of tissue perfusion. Male Wistar rats (n = 20), aged between 6-8 months, with an average weight of 287 ± 26.74 g, were used. Animals were divided into two experimental groups: group A (n = 17; hindlimb chronic ischemia model) and group B (n = 3; control). Hindlimb ischemia was induced by concomitant ligation of the right femoral and popliteal artery. Evaluation of tissue perfusion was quantified in perfusion units (PU) on a scale from 0 to 500 (500 PU = maximal detectable perfusion) by laser Doppler analysis at day 0, day 15 and day 30 after induction of ischemia. Induction of chronic ischemia in the rat hindlimb by concomitant ligation of the femoral and popliteal artery can be readily obtained but requires basic microsurgical skills. Laser Doppler analysis has shown unaltered ischemia levels throughout the study (129,17 PU ± 3.13 day 0 vs. 130,33 PU day 30 ± 3,27, p = not significant (n.s.)). We demonstrate a simple and reproducible model of chronic hindlimb ischemia in rats, with stable tissue perfusion levels that are accurately quantified using laser Doppler technology. Hence, this model can represent a valid tool for further studies involving therapeutic neoangiogenesis.

Unilateral left four renal arteries: case report using MDCT angiography.

We report a very rare case of a 57-year-old male who presented four left renal arteries (RAs) [one main RA and three additional renal arteries (AdRAs)] highlighted incidentally on multidetector computed tomography (MDCT) angiography, which was used to investigate the vascular system of the lower limbs. The distance between the extreme points of RAs origin (upper and lower points of origin) from abdominal aorta (AA) was in the left part of 9.83 cm. The distance between the extreme points of penetration (upper and lower points of penetration) into the left renal parenchyma was 5.23 cm. At the level of origin, the main left RA has an endoluminal diameter of 0.63 cm, much larger in comparison to the other additional left RAs (0.43 cm, 0.33 cm and 0.28 cm, respectively). The length of the main left RA was 2.16 cm, significantly shorter in comparison with the other additional left RAs (2.21 cm, 4.26 cm and 4.73 cm, respectively). The second left RA was the main RA; the first left RA was AdRA (polar superior RA); the third left RA was AdRA (hilar RA); the fourth RA was AdRA (polar inferior RA). Knowledge of this anatomical variation should be considered in planning and performing renal vessel surgery, and kidney transplantation.

An anomalous origin of the gastrosplenic trunk and common hepatic artery arising independently from the abdominal aorta: a case report using MDCT angiography.

The authors describe a case of a 61-year-old female patient, which presented on multidetector computed tomographic (MDCT) angiography a gastrosplenic trunk (GST) and common hepatic artery (CHA) arose independently from abdominal aorta (AA). The GST arose from the anterior wall of the AA, at the level of upper edge of the L1 vertebral body. The left gastric artery (LGA) arose from the superior wall of the GST. The splenic artery (SA) continuous the path of GST. The CHA arose from the anterior wall of the AA, at the level of upper one third of the L1 vertebral body, at 15.3 mm above the origin of superior mesenteric artery (SMA). The incidence and developmental and clinical significance of this vascular variation is discussed with a detailed review of the literature.

A new technique for minimal invasive complete spinal cord injury in minipigs.

BACKGROUND: The aim of this study was to develop a minimal invasive complete spinal cord injury (SCI) minipig model for future research applications. The minipig is considered a translationally relevant model for SCI research. However, a standardized minimal invasive complete SCI model for pigs has not yet been established. METHODS: Adult Göttingen minipigs were anesthetized and placed in extended prone position. After initial computed tomography (CT) scan, the skin was incised, a needle placed in the epidural fatty tissue. Using the Seldinger technique, a guidewire and dilators were introduced to insert the balloon catheter to Th12. After confirmation of the level Th11/Th12, the balloon was inflated to 2 atm for 30 min. The severity of the lesion was followed by CT and by MRI, and by immunohistochemistry. Function was assessed at the motor and sensory level. RESULTS: Duration of procedure was about 60 min including the 30-min compression time. The balloon pressure of 2 atm was maintained without losses. The lesion site was clearly discernible and no intradural bleeding was observed by CT. Neurological assessments during the 4-month follow-up time showed consistent, predictable, and stable neurological deficits. Magnetic resonance imaging analyses at 6 h and 4 weeks post SCI with final immunohistochemical analyses of spinal cord tissue underlined the neurological outcomes and proved SCI completeness. CONCLUSIONS: We have established a new, minimal invasive, highly standardized, CT-guided spinal cord injury procedure for minipigs. All risks of the open surgery can be excluded using this technique. This CT-guided SC compression is an excellent technique as it avoids long surgery and extensive trauma and allows a feasible inter-animal comparison.

Multiple congenital anomalies of carotid and vertebral arteries in a patient with an ischemic stroke in the vertebrobasilar territory. Case report and review of the literature.

The congenital anomalies of the supra-aortic arteries and their branches as potential risk factors for cerebrovascular insufficiency are not yet fully investigated and clarified. This report describes the case of a 68-year-old man who was admitted in our Clinic for an acute ischemic stroke in the vertebrobasilar territory. Extracranial color-coded duplex sonography (CCDS) and computed tomography angiography revealed a combination of congenital anomalies of the neck arteries: left internal carotid artery hypoplasia, left common carotid artery hypoplasia, right vertebral artery hypoplasia and the emergence of the left vertebral artery directly from the aortic arch. The aim of this article is to emphasize the value of CCDS as an accurate, non-invasive method of assessing the neck arteries and, also, the importance of the morphological anomalies of the carotid and vertebral arteries in the cerebral hemodynamics.

Is Contrast Enhanced Ultrasonography a useful tool in a beginner's hand? How much can a Computer Assisted Diagnosis prototype help in characterizing the malignancy of focal liver lesions?

AIM: Contrast enhanced ultrasound (CEUS) improved the characterization of focal liver lesions (FLLs), but is an operatordependent method. The goal of this paper was to test a computer assisted diagnosis (CAD) prototype and to see its benefit in assisting a beginner in the evaluation of FLLs. MATERIAL AND METHOD: Our cohort included 97 good quality CEUS videos[34% hepatocellular carcinomas (HCC), 12.3% hypervascular metastases (HiperM), 11.3% hypovascular metastases (HipoM), 24.7% hemangiomas (HMG), 17.5% focal nodular hyperplasia (FNH)] that were used to develop a CAD prototype based on an algorithm that tested a binary decision based classifier. Two young medical doctors (1 year CEUS experience), two experts and the CAD prototype, reevaluated 50 FLLs CEUS videos (diagnosis of benign vs. malignant) first blinded to clinical data, in order to evaluate the diagnostic gap beginner vs. expert. RESULTS: The CAD classifier managed a 75.2% overall (benign vs. malignant) correct classification rate. The overall classification rates for the evaluators, before and after clinical data were: first beginner-78%; 94%; second beginner-82%; 96%; first expert-94%; 100%; second expert-96%; 98%. For both beginners, the malignant vs. benign diagnosis significantly improved after knowing the clinical data (p=0.005; p=0,008). The expert was better than the beginner (p=0.04) and better than the CAD (p=0.001). CAD in addition to the beginner can reach the expert diagnosis. CONCLUSIONS: The most frequent lesions misdiagnosed at CEUS were FNH and HCC. The CAD prototype is a good comparing tool for a beginner operator that can be developed to assist the diagnosis. In order to increase the classification rate, the CAD system for FLL in CEUS must integrate the clinical data.

Fusiform aneurysm of a persistent primitive trigeminal artery associated with cerebrovascular anatomic variations: a report of two cases.

There are four embryonic anastomoses that exist between the internal carotid artery (ICA) and the vertebrobasilar (VB) system, which may fail to regress postfetal life; one of which is the trigeminal artery. Other persistent anastomoses include those formed by the hypoglossal, otic and proatlantic intersegmental arteries. In addition, other cerebrovascular variations may accompany a persistent primitive trigeminal artery (PPTA); such as arteriovenous malformations, aneurysms, carotid-cavernous fistulas and stenotic cerebral vessels. We present two very rare cases of a left PPTA. In the first case, there was a past medical history significant for cervico-thoraco-lumbar spondylitis and in the second case of an operated occipital astrocytoma. In both cases, the PPTA was associated with a fusiform aneurysm located in the carotidian (lateral) aspect of the PPTA as well as other cerebrovascular anatomic variations. In the first case, the length of the PPTA was 26.0 mm and its endoluminal diameter, at its origin at the ICA, was 1.8 mm; the aneurysm has a length of 8.4 mm. In the second case, the length of the PPTA was 31.0 mm and its endoluminal diameter at its origin at the ICA was 3.0 mm; the aneurysm have a length of 7.6 mm. Identification of these variant vessels should not be ignored before planning and execution of neurosurgeries to prevent possible perioperative risks.

Congenital solitary kidney with multiple renal arteries: case report using MDCT angiography.

A congenital solitary kidney with multiple renal arteries is a rare congenital abnormality that can occur in the presence of multiple other anomalies. We describe an atypical case of a right congenital solitary kidney with three renal arteries (RA) one main RA and two additional renal arteries in a 75-year-old woman with uterine didelphys. The main RA had an intraluminal diameter larger than the diameter of the additional renal arteries (AdRAs) at the origin (0.53 cm for the main RA; 0.49 cm and 0.32 cm for the two AdRAs). Both the AdRAs had a greater length than the main RA (3.51 cm for the main RA; 3.70 cm and 4.77 cm for the two AdRAs). The calculated volume of the kidney was 283 cm³, while the volume of the renal parenchyma was 258 cm³. Knowledge of this variant is extremely important in clinical practice as it has been found to be associated with proteinuria, hypertension and renal insufficiency.

Fenestration of the middle cerebral artery in a patient who presented with transient ischemic attack.

Cerebral artery fenestrations are usually detected incidentally during angiography, have a reported incidence ranging from of 0.03% to 1%, and rarely cause neurological symptoms. They can, however, be associated with aneurysmal dilatation at the proximal or distal end of the fenestration, cerebral arteriovenous malformations, or (rarely) ischemic symptoms. We present a case of a 54-year-old obese woman who presented with a large convex-lens-like fenestration of the right middle cerebral artery (MCA) at the M1 segment (distal to the origin of the temporopolar artery) associated with a transient ischemic attack. The MCA fenestration caused a local change in hemodynamic blood flow, which leads to cerebral ischemia. Magnetic resonance angiography (MRA) also revealed an associated small slit-like fenestration of the basilar artery (BA), hypoplasia of the A1 segment of the right anterior cerebral artery, bilateral fetal posterior cerebral arteries, and bilateral absence of the posterior communicating arteries. To our knowledge, this is the sixth reported case of MCA fenestration with an associated ischemic attack. In our case, fenestrations of the MCA, the BA, and hypoplasia of the A1 segment of ACA were not associated with any aneurysms.

Single ectopic thoracic renal artery associated with a normal kidney position and renal artery stenosis: a case report and review of literature.

There are several reports of multiple ectopic renal arteries (RA) in the literature. However, the ectopic origin of a single RA with a normal kidney position is rare. Knowledge of this variant is extremely important in clinical, surgical and radiological practice. Using MDCT angiography examination, we describe a rare case of a right kidney located in a normal lumbal position with a single ectopic thoracic renal artery originating in the thorax, above the diaphragmatic dome, at the level of the upper one-third of the T12 vertebral body. With an "S"-shaped course and a total length of 103 mm, this artery had an intratoracic portion of 38 mm. It crossed the diaphragm at 23 mm lateral to the right side of the TA, through a hiatus located on the lateral side of the right crus of the diaphragm. The right inferior phrenic artery arose from the left lateral wall of the right RA, 5 mm below the level of CT (45 mm distal to the right RA origin). Remarkably, this variant was associated with an area of proximal arterial stenosis, which produced signs and symptoms of hypertension secondary to renal arterial stenosis. To the authors' knowledge, this is the first reported case of a stenotic single ectopic thoracic renal artery associated with a normal kidney position.

Duplication of the distal end of the left vertebral artery with fenestration of the right posterior cerebral artery.

The vertebrobasilar system (VBS) consists in the intracranial parts of the vertebral arteries (VAs), the basilar artery (BA) and its branches. The presence of a duplication at the level of the intracranial segment of VA (V4) is generally an incidental finding, but may be associated with aneurysms or arteriovenous malformations. We present an extremely rare case of duplication of the distal end of the left vertebral artery, associated with fenestration of the right posterior cerebral artery. The distal end of the left VA was duplicated into two arms (the right with a length of 5.5 mm and a diameter of 2.3 mm that connected with the contralateral VA; and the left with a length of 11.0 mm and a diameter of 1.6 mm, which connected more distally with the BA). The right posterior cerebral artery (PCA) had a fenestration in the posterior segment of the posterior communicating part (P2), with a length of 6.8 mm.

Fusiform aneurysm of a persistent trigeminal artery associated with rare intracranial arterial variations and subarachnoid hemorrhage.

The trigeminal artery is one of four primitive anastomoses between the internal carotid artery and vertebrobasilar system that regresses in the sixth week of fetal development. A persistent trigeminal artery (PTA) is generally an incidental finding but may also be associated with intracranial vascular pathologies such as aneurysms, arteriovenous malformations, and cranial nerve compression syndromes. We present an extremely rare case of a right PTA with an associated bleeding fusiform aneurysm located in the carotidian (lateral) part of the PTA. In addition, this rare anatomic variation was associated with bilateral absence of the posterior communicating arteries, a left posterior cerebral artery originating from the left internal carotid artery, and agenesis of the A1 segment of the left anterior cerebral artery.

Right lump kidney with varied vasculature and urinary system revealed by multidetector computed tomographic (MDCT) angiography.

Renal ectopia also known as ectopic kidney is an embryological renal anomaly characterised by abnormal anatomical location of one or both of the kidneys. This can occur in various forms such as (1) crossed fused renal ectopia, (2) ectopic thoracic kidney and (3) pelvic kidneys. The lump kidney is one of the six variations of crossed fused ectopic kidney. Throughout life, the patient may remain asymptomatic, however, symptomatic patients may present with minor traumatic injuries due to the abnormal location or normal kidney pathologies. During normal embryological development, there is cephalic migration during which the kidneys ascend to their normal retroperitoneal location; therefore, an ectopic location is as a result of arrested migration. During this embryological development the kidney has multiple aorto-illiac branches, which degenerate when the kidney reaches its normal location. Here they develop new renal branches from the aorta and during an arrested ascent the ectopic kidney tends to retain some of the older aorto-iliac vessels. Hence, the arterial supply and the veineux drainage are grossly abnormal, reflecting the metanephric malascent and the primitive vascular arrangement. The collecting systems also present with important anatomical variations. We present an extremely rare case of right lump kidney with six renal arteries, two renal veins and two duplicated pelvicalyceal systems.

A case of bilateral tracheal bronchus: report of a rare association in multidetector computed tomography bronchoscopy.

Bilateral tracheal bronchus is a rare variation of the tracheobronchial tree. We present a 1-year 7-month-old male patient who presented with sepsis following endotracheal intubation. Upon review of multidetector computed tomography images, the patient was diagnosed with displaced bilateral tracheal bronchus. Imaging showed a right-sided anomalous bronchus arising 0.9 cm proximal to the carina. The left-sided anomalous bronchus arose 0.7 cm proximal to the carina, mimicking a tracheal trifurcation. When viewed together, the close proximity of both the right and left tracheal bronchi to the carina created a distinct tracheal quadrifurcation. This rare anatomic variation was additionally associated with an anorectal malformation (anal atresia). Unrecognized tracheal bronchus in patients undergoing endotracheal intubation can lead to serious complications. While bilateral tracheal bronchus is described in the literature, we are unaware of any case similar to this patient presentation. We present and analyze this unusual case of bilateral tracheal bronchus. The anatomy and clinical significance of this variation is then discussed.

Bilateral triple renal arteries.

We report an atypical case of a 53-year-old male with the presence of six renal arteries (RAs) (bilateral triple) found incidentally on multi-detector computed tomography (MDCT) angiography, which was used to investigate peripheral vascular disease of the lower limbs. The distance between the extreme points of RAs origin from abdominal aorta (AA) was in right 4.42 cm, and in left 2.40 cm. The distance between the extreme points of penetration into the renal parenchyma was in right 2.01 cm, and in left 2.56 cm. On each side, the endoluminal diameter at the origin of the main RA (in right 0.54 cm, and in left 0.42 cm) was significantly larger in comparison with the other additional renal arteries (AdRAs) (in right 0.21-0.29 cm, in left 0.24-0.35 cm); however, the AdRAs were much longer (in right 7.42-10.82 cm, in left 5.90-6.85 cm) than the main RA (in right 6.21 cm, in left 5.73 cm). All the four AdRAs were hilar RAs. Knowledge of this anatomical variation should not be ignoring when planning the adequate interventional radiological and surgical procedure.

Persistent hypoglossal artery aneurysm located in the hypoglossal canal with associated subarachnoid hemorrhage.

The hypoglossal artery is one of four primitive anastomoses between the internal carotid artery and vertebrobasilar system that regresses in the sixth week of fetal development. A persistent hypoglossal artery (PHA) is generally an incidental finding but may also be associated with aneurysms or arteriovenous malformations. We present a rare case of a PHA with an associated bleeding intracranial PHA aneurysm located in the hypoglossal canal.

Seven renal arteries: a case report using MDCT angiography.

We report an atypical case of a 63-year-old male with the presence of seven renal arteries (RAs) (three right and four left) found incidentally on multi-detector computed tomography (MDCT) angiography which was used to investigate peripheral vascular disease of the lower limbs. Each arterial lumen was analyzed for the diameter at its origin; length and trajectory in the frontal plane (ascendant + or descendant -); and the distance between the point of origin from the abdominal aorta (AA) to its renal intraparenchymal penetration point. We also analyzed the distance between the extreme points of origin of the right and left RAs from the AA and the distance between the extreme points of penetration into the renal parenchyma of the right and left RAs. On each side, the endoluminal diameter at the origin of the main RA was significantly larger than that of the other AdRAs; however, the AdRAs were much longer than that of the main RA. From the six AdRAs, four were hilar RAs and two were superior polar RAs. Knowledge of such cases is of great clinical significance, as it may be beneficial in various urological operations or invasive arterial procedures.

Left crossed fused renal ectopia L-shaped kidney type, with double nutcracker syndrome (anterior and posterior).

Crossed fused renal ectopia (CFRE) is the second most common fusion anomalies (FAs) of the kidneys after horseshoe kidney. Crossed fused renal ectopia (CFRE) results from one kidney crossing over to the opposite side and subsequent fusion of the parenchyma of the two kidneys. We report, by multidetector-row computed tomography (MDCT) angiography, an extremely rare case of a left CFRE (L-shaped kidney type), consisting of multiple renal arteries (one main renal artery for the upper renal parenchyma, and three renal arteries (one main and two additional) for the lower renal parenchyma) and two left renal veins, which produced a double nutcracker syndrome (both anterior and posterior). The L-shaped left kidney has a maximum length of 18.5 cm, a maximum width of 10.2 cm, and a maximum thickness of 5.3 cm. The upper pole of the kidney is located at the level of the lower third of T12 vertebral body (4.6 cm left to the mediosagittal plan); the lower pole is located along the lower half of the L5 vertebral body (1.5 cm left to the mediosagittal plan). The following case will focus on the relevant anatomy, embryology, and the clinical significance of this entity.

Anomalous pattern of origin of the left gastric, splenic, and common hepatic arteries arising independently from the abdominal aorta.

The celiac trunk is the first unpaired midline branch of the abdominal aorta that usually gives rise to the left gastric artery (LGA), the common hepatic artery (CHA) and the splenic artery (SpA). Despite this classic arrangement, many variations exist. We describe an atypical case of an absent CT and anomalous origin of the LGA, CHA and the SpA from the abdominal aorta using multidetector computed tomography angiography (MDCTA) in a 72-year-old male patient. The LGA arose from the anterior wall of the AA at the level of the T12-L1 intervertebral disk [33.8 mm above the origin of the superior mesenteric artery (SMA)]. The SpA originated directly from the anterolateral wall of the AA at the junction of the upper-third and middle-third of the L1 vertebral body (24.8 mm above the origin of the SMA). The CHA branched directly from the anterior wall of the AA at the level of the middle-third of the L1 vertebral body (17 mm above the origin of the SMA). The 64-slice MDCTA system has become the primary tool for evaluation of abdominal blood vessels. It is important to be aware of such a variation as it can have a significant impact on surgical and clinical practice.