Redefining the vascular anatomy of the medial gastrocnemius muscle: A computed tomography angiography study.

BACKGROUND: The medial gastrocnemius (GN) muscle flap is a historical reconstructive option in lower limb reconstruction. The flap is proximally based on the medial sural artery, and it is assumed not possible to harvest a distally based flap because of the absence of other minor pedicles. The aim of this study is to investigate the presence and the anatomy of a distal secondary pedicle given off by the posterior tibial artery (PTA). METHODS: A retrospective CTA study was performed of 120 limbs between April 2018 and June 2020. 3D reconstruction was performed to delineate the anatomy of the distal secondary pedicle, if present. The distance of the pedicle, if found, from the intermalleolar line to the patella was noted. The number of pedicles, if multiple, was documented, as well as branches to the soleus muscle and the skin. RESULTS: A distal pedicle to the gastrocnemius muscle was found in 64% of limbs. The average location from the intermalleolar line is 168 mm. The branching pattern from the PTA showed an isolated vessel going to the distal medial gastrocnemius (32.8%), two branches to the medial gastrocnemius and skin (39.3%), two branches to the medial gastrocnemius and soleus (24.6%), and three branches to the medial gastrocnemius, soleus, and the skin (3.3%). CONCLUSIONS: This study confirms the presence of the secondary axial distal pedicle of the GN muscle. Furthermore, this study confirms that there is a likely association between the distal medial gastrocnemius pedicle and the PTA skin perforators.

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.

A sequence of flaps and dissection exercises in the living model to improve the learning curve for perforator flap surgery.

INTRODUCTION: The training to learn how to perform perforator flaps requires practice on a living model to optimize dissection and to evaluate outcome. The purpose of this study was to describe a training model that optimizes the use of animals in order to perform the maximum number of exercises per animal. MATERIAL AND METHODS: The sequence has been planned and practiced by the first and last author, recorded perfected and implemented in a two-day surgical course. The sequence was then evaluated by the trainers and the trainees by means of a questionnaire. RESULTS: All students were able to complete the sequence of exercises before the end of the second day except two (8/10) who could not complete one exercise each. The students considered the Deep Superior Epigastric Artery Perforator flap the most difficult to perform, being the most technically demanding. The sequence of exercises was judged either easily reproducible or reproducible by all the students. Two students suggested to postpone the DSEAP flap to the second day, after some training, to optimize the experience with the most challenging and rewarding flap. CONCLUSIONS: The training sequence proposed offers a wide range of exercises and allows four trainees, divided in two teams, to work and learn on the same animal. They can perform a wide range of flaps and also harvest the internal mammary vessels. The living model allows for evaluation of the quality of the surgical performance, judged by the difficulties and complications encountered during dissection, and finally through the feedback of flap perfusion.

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.

Induction of therapeutic neoangiogenesis using in vitro-generated endothelial colony-forming cells: an autologous transplantation model in rat.

BACKGROUND: Accumulating evidence shows the potential of bone marrow-derived endothelial colony-forming cells (bmECFCs) as promising tools for vascular repair. However, knowledge about their in vitro expansion, characterization, and functional behavior is still controversial. We demonstrate the in vitro generation of rat bmECFCs and analyze their ability to promote tissue reperfusion in a chronic hind-limb ischemia model. METHODS: Either in vitro-generated and characterized autologous bmECFCs or placebo was injected into ischemic hind limbs of Sprague-Dawley rats. Tissue perfusion was quantified by laser Doppler, in perfusion units (PU), at days 0, 15, and 30. RESULTS: Rat bmECFCs acquire a typical phenotype (CD34(+)VEGFR2(+)CD133(+)CXCR4(+)CD45(-)), culture, and functional behavior (Dil-ac-LDL+) in vitro. Injection of autologous bmECFCs improves tissue perfusion in ischemic hind limbs (183.5 ± 3.29 PU(bmECFCs/day 30)versus 131 ± 3.9 PU(controls/day 30), P < 0.001). CONCLUSIONS: We conclude that rat bmECFCs promote ischemic tissue reperfusion and their proangiogenic properties are a potential mechanism for this effect.

Post-traumatic combined flexion of the thumb, index and middle finger after intrinsic muscles reconstruction of the hand: a case report.

We report a case in which simultaneous flexion of the thumb, index and middle finger occurred 6 months after the surgical reconstruction of the adductor (AM) and first dorsal interosseous (IO) muscles. An anomalous connection in the form of tendon slip associated to fibrous adhesions between the flexor pollicis longus (FPL) tendon, flexor digitorum profundus indicis (FDPI) and middle finger (FDPM) tendons were found. Either ultrasound (US) examination or magnetic resonance imaging (MRI) were unable to detect the site of adhesion. Excision of the slip and radical tenosynoviectomy led to early functional recovery.

False aneurysm of the common digital artery. Is reconstruction with an arterial graft worth the efforts? A case report.

False aneurysms in the hand are rare. A false aneurysm of the common digital artery in the palm for the second and third finger is reported, illustrating our experience with arterial graft reconstruction after excision as a valid alternative surgical therapy to a vein graft, when ligation or end-to-end anastomosis are not indicated or feasible. The superficial palmar branch of the radial artery was chosen as donor vessel based on the similarity in vessel diameter and wall thickness to the common digital arteries. Ease of harvesting and performing the microvascular anastomosis using an arterial graft allows for a viable reconstruction after false aneurysm excision in the palm.

Surgical vacuum-assisted closure for treatment of dramatic case of stonefish envenomation.

Skin necrosis of the foot, oedema and lymphangitis from stonefish (Synanceia verrucosa) sting are complications well known for a long time and with potential long-term sequelae. Literature reports of stonefish envenomation give no specific reference on soft tissue management and surgical reconstruction. This is the first report describing a case of foot stonefish envenomation treated by vacuum-assisted closure therapy as an easy to use, accessible and simple adjuvant tool for management of large soft tissue necrosis.

The versatility of propeller flaps for lower limb reconstruction in patients with peripheral arterial obstructive disease: initial experience.

In this study, we evaluate the feasibility of propeller flaps, for soft tissue reconstruction in patients with peripheral arterial obstructive disease (PAOD). Five patients (average age, 72 years old), presenting with necrosis of several foot units, were diagnosed with stage IV PAOD and diabetes mellitus. All underwent revascularization, followed by soft tissue reconstruction using propeller flaps. A total of 6 flaps were performed, with dimensions ranging from 4 x 7 cm to 8 x 31 cm. Perforator origin was the peroneal (5 flaps) or the tibial posterior artery (1 flap). Average operative time was 190 minutes. Overall patency was 83.3%; 1 case was complicated with total flap loss followed by below-knee amputation; 1 case developed partial necrosis necessitating skin grafting. All flaps developed mild postoperative edema, which resolved spontaneously. Propeller flaps prove to be useful tools for soft tissue reconstruction in patients with PAOD because of low operative morbidity, easy technique with fast learning curve, and low complications rate.

Thoracoscopic approach of the internal mammary artery (IMA): a training model in pigs.

Endoscopic internal mammary artery (IMA) approach represents a well-established procedure in coronary bypass surgery. However, such techniques require highly trained skills that need to be mastered in experimental models before taken into the clinic. To attain such skills, our aim was to develop a training model of thoracoscopic approach for harvesting of the IMA in pig. Ten pigs of either sex, weighing 20-28 kg, were used. The thoracic cavity was accessed with the animal in a lateral decubit position, through two ports of 10 mm and 1 of 5 mm, inserted on the anterior and posterior axillary lines immediately below the infrascapular angle into the pleural cavity, and a 30 degrees Hopkins II telescope. The internal mammary artery (IMA) was identified and dissected from its origin in the subclavian artery until its distal part where it becomes the deep superior epigastric artery. Afterward, the arterial segment was clipped and harvested. The mean operative time was 73 min. Postoperative survival at 72 hours was 100% and 90% at 4 weeks. A mean length of 3.2 cm of IMA graft was obtained (2.8-4 cm). The pig IMA has no intercostal branches; thus, the mobilization of the vessel being greatly facilitated. The procedure has two critical steps: the proper trocar insertion and the dissection of the middle one-third of the IMA. Endoscopic-assisted IMA, harvesting in pigs, represents a useful tool for training in minimally invasive heart surgery and supports further development toward other clinical applications.

Video-assisted versus conventional microsurgical training: a comparative study in the rat model.

Recent technical development has led to remarkable performances in video-guided surgical procedures. A video-endoscopic system (VES) is evaluated as an alternative magnifying solution for microsurgical procedures and compared to table-top microscopes in terms of technical and surgical aspects. Six surgical residents without microsurgical experience, alternating both systems, performed each 12 aortic end-to-end anastomoses on Sprague-Dawley rats using the triangulation technique. All anastomoses underwent quality review, total and single suture time, suture spacing, vessel bite, vessel overlapping and wall penetration were evaluated and graded. Overall anastomosis quality score was 52.28 (out of a maximum of 140) using the microscope and 42.7 using the VES. Despite significant differences in total anastomosis time, the learning curves are similar for the two systems and no major differences were noted in terms of overall anastomosis quality. Video-assisted microsurgery can become a useful instrument for microsurgery training.