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.

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.

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.

An unusual origin of the celiac trunk and the superior mesenteric artery in the thorax.

The authors report a case of a 44-year-old male found to have unusual origins of the celiac trunk (CT) and superior mesernteric artrery (SMA) as revealed by routine multidetector computed tomograph (MDCT) angiography. The CT and SMA originate from the thoracic aorta (TA) 21 mm and 9 mm above the aortic hiatus, respectively. The median arcuate ligament (MAL) is located at the level of the L1-L2 intervertebral disc. The course of the CT descends in the thoracic cavity making a 14° acute downward angle in front of the TA; below the level of the MAL, the CT descends, making an angle of 47°. The course of the SMA descends at both the thoracic and abdominal level making an angle of 17°, and having an aortomesenteric distance of 9 mm at the level of the third part of the duodenum. In the present case, the supradiaphragmatic origin of the CT and the SMA was determined by their incomplete caudal descent, associated with a pronounced apparent descent of the diaphragm. A thoracic origin of the CT and SMA and the acute downward aortomesenteric angle (17°) associated with a reduced aortomesenteric distance at the level of the third part of the duodenum (9 mm), although no clinical signs are present, may predispose the patient to develop simultaneously a triple syndrome: the compression of CT by MAL (celiac axis compression syndrome), the compression of SMA by MAL (superior mesenteric artery compression syndrome), and the compression of the duodenum by the SMA (superior mesenteric artery syndrome).

Rare case of the trunk of the inferior phrenic arteries originating from a common stem with a superior additional left renal artery from the abdominal aorta.

We describe in this article a rare case of a 39-year-old male with an inferior phrenic arteries trunk (IPAaT) originating from a common stem with a superior additional left renal artery (SAdLRA) from the abdominal aorta as revealed by routine multidetector computed tomography angiography. The IPAaT with an endoluminal diameter at the origin of 2.8 mm had an upward path with a total length of 18.4 mm, forking to the right inferior phrenic artery and left inferior phrenic artery. These two arteries had an endoluminal diameter at the origin of 1.7 mm and 2.0 mm, respectively. The presence of the common stem of the IPAaT with a SAdLRA and the length of the IPAaT complicate selective chemoembolization of the liver parenchyma.

Absence of the celiac trunk: case report using MDCT angiography.

The authors describe a case of a 57-year-old male patient with peripheral vascular disease which presented on MDCT angiography the absence of the celiac trunk (CT). The left gastric artery (LGA), common hepatic artery (CHA), and splenic artery (SA) (with an internal diameter at origin of 3.3, 6.0, and 6.2 mm, respectively) originated directly and independently from the abdominal aorta (AA). The LGA arose from the anterior wall of the AA [27 mm above the origin of the superior mesenteric artery (SMA)]. The SA and CHA arose from the left side of the anterolateral wall of the AA at 19 and 14 mm (respectively) above the origin of the SMA. The incidence and developmental and clinical significance of this vascular variation are discussed with a detailed review of the literature.

Bilateral quadruple renal arteries.

Variation in the number of renal arteries (RAs) constitutes the most common and clinically important renal vascular variation. In this study, the authors describe a rare case of a 58-year-old male with eight RAs (bilateral quadruple) as revealed by routine multidetector computed tomography angiography. All the eight RAs originated from the abdominal aorta and penetrated the renal parenchyma at the level of renal sinus. The main RAs had the intraluminal diameter larger than the diameter of the additional renal arteries (AdRAs) at the origin. All the AdRAs had a greater length than the main RAs. These aspects are particularly important in planning microsurgical procedures.