Modified deep iliac circumflex osteocutaneous flap for extremity reconstruction: anatomical study and clinical application.

BACKGROUND: The classic deep iliac circumflex osteocutaneous flap with iliac crest has been one of the most commonly used flaps for mandibular reconstruction since its advent. However, the unnecessary bulk of the 'obligatory muscle cuff' limited its widespread use. The authors describe in this article the use of a modified deep iliac circumflex osteocutaneous flap with reduced bulk and great mobility between the skin and the bone components. METHODS: This study was divided into two parts: anatomical study and clinical application. In the anatomical study, 40 sides of adult cadaveric specimens perfused with red gelatin in the arteries were dissected with the anterior superior iliac spine and the inguinal ligament serving as the anatomical landmarks to observe the course and the branches of the deep circumflex artery, with its terminal part being given priority. Clinically, five patients received modified deep iliac circumflex osteocutaneous flaps for extremity reconstruction. RESULTS: The anatomical study showed that the terminal part of the deep circumflex iliac artery ended as a musculocutaneous perforator with a diameter of 1.0 ± 0.1 mm, which could be located 6.2 ± 1.2 cm posterior and 1.5 ± 0.6 cm lateral to the anterior superior iliac spine. As for clinical application, in four cases osteocutaneous flaps survived completely, while that in one case suffered partial loss of the skin component. CONCLUSIONS: The modified deep iliac circumflex osteocutaneous flap enjoys a great degree of mobility between the skin and the bone components; it has greater manoeuvrability compared to the conventional one for the reconstruction of complex three-dimensional defects. The donor site of the skin flap is confined to the lower abdominal region, facilitating direct closure.

Convenient coverage of soft-tissue defects around the knee by the pedicled vastus medialis perforator flap.

Various reconstructive methods have been reported for coverage of soft-tissue defects around the knee; however, there is still no report about the pedicled vastus medialis perforator flap; hence, this article aims to elaborate on this approach for resurfacing of defects around the knee. From January 2010 to December 2010, six patients with defect size ranging from 5.0 × 3.3 to 10.5 × 7.0 cm received soft-tissue coverage with the pedicled vastus medialis perforator flap. Among them, five cases were male, and the other female. The age of patients ranged from 20 to 52 years, with an average of 34.5 years. The injury of one patient was caused by being crushed by a heavy metal object, and the rest sustained injuries in traffic accidents. The defect in one case was located at the inferomedial aspect of the thigh, and the rest around the knee. Five flaps survived completely, while one case suffered marginal necrosis due to infection. The donor sites healed without complication. Postoperative follow-ups of the patients ranged from 1 to 18 months. Through the article, we demonstrate the feasibility of using the pedicled vastus medialis perforator flap for reconstruction of knee injuries, which makes the knowledge of the vastus medialis-related flap series more complete and also enriches the methods of repairing defects around the knee.

The microanatomical structure of the cistern of the lamina terminalis.

Microanatomical dissection was performed on 14 formalin-fixed human cadaveric head specimens to provide information relevant for surgical procedures involving the cistern of the lamina terminalis (LT). The cistern of the LT was located in the midline of the telencephalon and was tent-shaped. The superior wall was located between the septal areas bilaterally, the lateral walls leaned laterally downwards, the anterior wall was the integrated line of the bilateral leptomeninges, the posterior and the inferoposterior walls were composed of the LT, the inferior margin was the arachnoid membrane between the optic nerves, and the inferoanterior wall usually formed a recess in front of the optic chiasm. In summary, the shape of the cistern of the LT is relatively constant, which is helpful for predicting the direction of hemorrhage of an aneurysm of the anterior communicating artery; in distinguishing its neural, vascular, and fibrous contents; and guiding surgical procedures.

Microsurgical anatomy of Liliequist's membrane demonstrating three-dimensional configuration.

OBJECT: Liliequist's membrane (LM) is an important arachnoid structure in the basal cisterns. The relevant anatomic descriptions of this membrane and how many leaves it has are still controversial. The existing anatomical theories do not satisfy the needs of minimally invasive neurosurgery. We aimed to establish the three-dimensional configuration of LM. METHODS: Fifteen adult formalin-fixed cadaver heads were dissected under a surgical microscope to carefully observe the arachnoid mater in the suprasellar and post-sellar areas and to investigate the arachnoid structure and its surrounding attachments. RESULTS: It was found that the LM actually consists of three types of membranes. The diencephalic membrane (DM) was usually attached by the mesencephalic membrane (MM) from underneath, and above DM it was usually a pair of hypothalamic membranes (HMs) extending superomedially. The pair of HMs was stretched between the DM (or MM) and the hypothalamus and were seldom attached to the carotid-chiasmatic walls between the carotid cistern and the chiasmatic cistern. These three types of membranes (DM, MM, and HM) comprised the main arachnoid structure in the anterior incisural space and often presented as four connected leaves. However, only two thirds of the specimens had all three types of membranes, and there was considerable variation in the characteristics and shapes of the membranes among the specimens. CONCLUSION: All three types of membranes comprising LM serve as important anatomical landmarks and interfaces for surgical procedures in this area.

Anatomic and radiological study on posterior pedicle screw fixation in the atlantoaxial vertebrae of children.

OBJECTIVE: To investigate the feasibility of posterior fixation with 3.5-mm pedicle screws in the atlantoaxial vertebrae of children. METHODS: In this study, atlantoaxial vertebrae specimens were obtained from 10 cadavers of children aged 6-8 years. We measured the height and width of the C(1) pedicle and the midportion of C(1) lateral mass; the width of C(1) posterior arch under the vertebral artery groove and the height of the external and internal one-third of this part; the external, internal height and the superior, middle, inferior width of the C(2) pedicle (transverse foramen). Furthermore, computed tomography (CT) axial scan was performed on 20 age-matched volunteers to obtain relative data of their atlantoaxial vertebrae. We measured the length and width of the C(1) and C(2) pedicles in the atlantoaxial cross-sectional plane. On CT workstation, we also measured the angles between the longitudinal axes of the atlantoaxial pedicles and the midsagittal plane. RESULTS: For the cadaveric specimen group, the height and width of the C1 pedicle were (5.26+/-0.44) mm and (6.26+/-0.75) mm respectively. The height of the medial one-third of the C1 posterior arch under the vertebral artery groove was (4.07+/-0.24) mm. The external, internal height and superior, middle, inferior width of the C2 pedicle was (6.86+/-0.48) mm, (6.67+/-0.49) mm, (6.63+/-0.61) mm, (5.41+/-0.39) mm and (3.71+/-0.30) mm, respectively. For the volunteer group measured by CT scan, the height and width of the C(1) pedicle were (5.47+/-0.34) mm and (6.63+/-0.54) mm respectively, while (6.59+/-0.51) mm and (5.13+/-0.42) mm of the C2 pedicle. The angles between the atlas, axis pedicles and the midsagittal plane were (9.60+/-1.32) degree and (27.80+/-2.22) degree respectively. CONCLUSION: It is feasible to place a 3.5-mm pedicle screw in the C(1) and C(2) pedicles of children aged 6-8 years old.

Medial malleolus and deltoid ligament reconstruction in open ankle fractures with combination of vascularized fibular head osteo-tendinous flap and free flap transfers.

Treatment of the traumatic bone and soft tissue defect of the medial ankle is a challenge in reconstructive orthopedic surgery. In this report, we described a novel reconstruction procedure for the medial malleolus reconstruction using microsurgical transfer of the fibular head osteo-tendinous flap combined with a free latissimus dorsi flap (free LD flap) or a free anterolateral thigh flap (free ALT flap) in six patients. The sizes of the wounds ranged from 10 x 8 cm to 24 x 10 cm, and the sizes of the LD and ALT flaps were from 12 x 9 cm to 24 x 12 cm. All transplants survived. Five patients had primary wound healing. One patient had fibular graft and soft tissue infection that caused delayed healing. On average 4 months after surgery, all patients were able to stand and walk without crutch assistance. With a mean follow-up of 3.5 years (range, 1-5 years), all patients achieved stable ankles and were satisfied with the range of motion with excellent American Orthopedic Foot and Ankle Society functional scores (> 85). The fibular head resembles the medial malleolus in morphology. Vascularized fibular head transfer combined with a free flap provides satisfactory results for complex medial malleolus reconstruction.

Microanatomy and surgical relevance of the olfactory cistern.

All surgical approaches to the anterior skull base involve the olfactory cistern and have the risk of damaging the olfactory nerve. The purpose of this study was to describe the microanatomical features of the olfactory cistern and discuss its surgical relevance. In this study, the olfactory cisterns of 15 formalin-fixed adult cadaveric heads were dissected using a surgical microscope. The results showed that the olfactory cistern was situated in the superficial part of the olfactory sulcus, which separated the gyrus retus from the orbital gyrus. In coronal section, the cistern was triangular in shape; its anterior part enveloped the olfactory bulbs and was high and broad; its posterior part was medial-superior to internal carotid artery and was also much broader. There were one or several openings in the inferior wall of the posterior part in 53.4% of the cisterns. The olfactory cistern communicated with the surrounding subarachnoind cisterns through these openings. The middle part of the olfactory cistern gradually narrowed down posteriorly. Most cisterns were spacious with a few fibrous trabeculas and bands between the olfactory nerves and cistern walls. However 23% of the cisterns were narrow with the cistern walls tightly encasing the olfactory nerve. There were two or three of arterial loops in each olfactory sulcus, from which long, fine olfactory arteries originated. The olfactory arteries coursed along the olfactory nerve and gave off many terminal branches to provide the main blood supply to the olfactory nerve in most cisterns, but the blood supply was in segmental style in a few cisterns. Moreover, the veins of the cistern appeared to be more segmental than the olfactory arteries in most cisterns. These results suggested that most olfactory cisterns are spacious with relatively independent blood supply, and it is reasonable to separate the olfactory tract with its independent blood supply from the frontal lobe by 1-2 cm in the subfrontal approach, the pterional approach, or anterior interhemispheric approach. However, in the minority of cases, separation of the olfactory tract is not safe because of the anterior origin of the olfactory arteries or segmental blood supply. It is difficult to separate the olfactory nerve without any damage to the olfactory nerve, even with very skilled hands.

Anatomic study of distally based pedicle compound flaps with nutrient vessels of the cutaneous nerves and superficial veins of the forearm.

The purpose of this study was to describe the anatomic basis for a distally based neurovenovascular pedicle compound flap, with nutrient vessels of the cutaneous nerves and superficial veins of the forearm. In this study, the origins, branches, and anastomoses of nutrient vessels of the cutaneous nerves and superficial veins of the forearm and their relationships with the blood supply of adjacent muscle, bone, and skin were assessed in 96 adult cadavers by perfusion of red gelatin into the superior limb arteries. The results showed that the nutrient vessels of cutaneous nerves and superficial veins of the forearm were found to have multiple origins, consisting of six longitudinal vascular plexuses and one transverse vascular plexus of the forearm, as follows: 1) the anterior-lateral vascular plexus from cutaneous branches of the radial artery; 2) the anterior-medialis vascular plexus from cutaneous branches of the ulnar artery; 3) the dorso-lateral vascular plexus from radial osteal and cutaneous branches; 4) the dorso-medialis vascular plexus from ulnar osteal and cutaneous branches; 5) the radial vascular plexus from osteal and cutaneous branches of the radial artery, cutaneous branches of the radial artery in the upper wrist, recurrent branches of the styloid process of the radius, and the radialis vascular plexus of cutaneous branches of the tabatière anatomique (anatomical snuffbox); and 6) the ulnar lateral vascular plexus from cutaneous branches of the ulnar artery in the upper wrist and osteal and cutaneous branches. The transverse vascular plexus is composed of dorsal branches of the ulnar and radial arteries. These perforating branches give fascial branches, cutaneous branches, periosteal branches, and nutrient vessels of cutaneous nerves and superficial veins. These results suggest that nutrient vessels of the cutaneous nerves and superficial veins of the forearm have the same origins as those of the nutrient vessels of adjacent muscles, bones, and skin of the forearm, which can be designated as five types of distally based pedicle flaps with nutrient vessels of cutaneous nerves and superficial veins of the forearm, whose rotation point is at the wrist joint. This flap can be applied to repair tissues of distal parts of the hand.

Modified distally based sural neuro-veno-fasciocutaneous flap: anatomical study and clinical applications.

The distally based sural neuro-veno-fasciocutaneous flap has been used widely for reconstruction of foot and ankle soft-tissue defects. The distal pivot point of the flap is designed at the lowest septocutaneous perforator from the peroneal artery of the posterolateral septum, which is, on average, 5 cm (4-7 cm) above the lateral malleolus. A longer neuro-veno-adipofascial pedicle would be needed to reversely reach the distal foot defect when the flap is dissected based on this perforating branch, which may result in more trauma in flap elevation and morbidity of the donor site. In this article, we explored new pivot points for this distally based flap in an anatomic study of 30 fresh cadavers. The results showed that the peroneal artery terminates into two branches: the posterior lateral malleolus artery and lateral calcaneal artery. These two branches also send off cutaneous perforators at about 3 and 1 cm above the tip of lateral malleolus, respectively, which can be used as arterial pivot points for the flap. A communicating branch between the lesser saphenous vein and the peroneal venae comitantes was found, accompanied by the perforator of the posterior lateral malleolus artery. This modified, distally based sural flap with lower pivot points was successfully transferred for repair of soft-tissue defects in 21 patients. The size of flaps ranged from 4 x 3 cm to 18 x 12 cm. All flaps survived without complications. Neither arterial ischemia nor venous congestion was noted. In conclusion, the vascular pivot point of a distally based sural flap can be safely designed at 1.5 cm proximal to the tip of the lateral malleolus. This modified flap provides a valuable tool for repair of foot and ankle soft-tissue defects.

Anatomy of the coronary sinus and its clinical significance for retrograde cardioplegia.

OBJECTIVE: To provide an anatomical basis for selecting optimal retrograde cardioplegia technique therefore to improve the effect of the operation. METHODS: Fifty formalin-fixed adult human cadaveric hearts were collected in this study, and special attention was given to the observation of the coronary sinus tributary drainage and the anatomical relationship between the orifice of the coronary sinus and the atrioventricular nodal artery. RESULTS: Although the majority of the tributaries drained into the coronary sinus, it was identified in 15 cases that the posterior vein of the left ventricle and in another 2 cases the small cardiac vein (SCV) made their way into the middle cardiac vein (MCV) respectively. In 6 cases MCV solely joined the right atrium, which was joined by SCV only in 1 case. Draining into the coronary sinus as seen in 44 cases, MCV had an opening 3.4+/-1.5 mm away from the orifice of the coronary sinus. In the direction perpendicular to the long axis of the coronary sinus orifice, the anterior and posterior extreme points were 4.9+/-2.5 mm and 9.9+/-4.2 mm respectively, away from the atrioventricular nodal artery, which crossed the long axis of the coronary sinus orifice at an angle of 21.2+/-15.6 degrees. The right atrial wall on both sides of the coronary sinus orifice was of a uniform thickness of 1.1+/-0.2 mm. CONCLUSIONS: Direct-vision non-balloon-tipped cannulation conforms better to the anatomical features described above. In purse-string suture, however, sufficient care should be taken of the dangerously thin inferior atrial wall and the close relationship between the coronary sinus orifice and the atrioventricular nodal artery. For better cardioprotective effect of retrograde cardioplegia, non-balloon-tipped cannula under direct vision should be adopted with the assistance of antegrade perfusion and, when necessary, additional transfusion via the exotic MCV opening may be used when the opening appears relatively wide.

[Anatomical study on reverse flap of dorso-ulnar aspect of mid-hand and its clinical application].

OBJECTIVE: To provide anatomical bases for dorso-ulnar aspect of mid-hand reverse flap. METHODS: After red latex was infused into the arteries of 40 sides of adult cadava upper limbs, the origin, course, branches, distribution and distal anastomosis on the dorsal carpal branch of ulnar arteries were observed. And the mid-hand flap transfer was used to repair two cases of soft tissue defect (ranged 4.5-5.0 cm x 2.0-3.5 cm on ring and little fingers). RESULTS: The dorsal carpal branch begins with ulnar artery (3.9 +/- 1.2) cm above the pisiform with diameter of (1.3 +/- 0.2) mm, and branches off into ascending and descending branches. The descending one is the continuing of dorsal branch, it crosses the ulnar edge of the fifth metecarpal bone and anastomizes with the digital artery of little finger or hypothenar branch of deep palmar (accounted for 70%). While the other ascending branch with the former two branches formed anastomosis accounts for 30%. The two cases got healed in one-stage. The function of fingers recovered after 3-4 month follow-up. CONCLUSION: The reverse flap of dorso-ulnar aspect of mid-hand is available to repair the soft tissue defect on dorsum of hand with neighbor finger.