Optimizing hook implantation angle of the clavicular hook plate: a cadaveric study.

PURPOSE: While Clavicle hook plates have demonstrated favorable results regarding bone and shoulder function, their design can potentially lead to complications due to pressure concentration at the plate's tip. This study aims to investigate the impact of different hook implantation angles on the contact surface area between the hook plate and acromion, with the goal of minimizing mismatch and maximizing contact surface area. METHODS: Twenty soft shoulder cadavers were included in the study, and the contact surface area of the hook plate was measured in different positions based on the hook implantation angle. RESULTS: The results showed variations in compatibility, width, and length of the contact surface area depending on the hook implantation angle and the medial or lateral row placement. The lateral row generally demonstrated superior compatibility (84.0% vs 46.67%, p-value < 0.001), with a broader contact area (3.55 ± 0.08 mm vs 3.09 ± 0.10 mm, p-value = 0.004) and a longer contact area (7.36 ± 0.19 mm vs 5.10 ± 0.23 mm, p-value < 0.001) at specific angles. A detailed analysis of the lateral position revealed that the zero angle of implantation resulted in the greatest contact surface area, measuring 3.91 ± 0.70 mm in width (p value = 0.083) and 8.85 ± 1.24 mm in length (p value < 0.001). CONCLUSION: Placing the hook laterally and at the zero position according to the hook implantation angle can maximize contact surface area, may reduce stress concentration, and minimize complications in hook plate fixation. Further research and consideration of anatomical variations are warranted to refine the placement technique and enhance patient outcomes. LEVEL OF EVIDENCE: Level V evidence.

Superficial Inferior Epigastric Artery Flap: Vascular Pattern and Territory Across the Midline.

BACKGROUND: Superficial inferior epigastric artery (SIEA) flap offers a significant advantage of lower donor site morbidity over other abdominal-based flaps for breast reconstruction. However, the inconsistent anatomy and territory across the midline remains a major issue. This study aimed to investigate the SIEA and determine its pattern and territory across the midline. METHODS: Twenty cadavers were studied. Ipsilateral dye was injected to the dominant SIEA. Dissection was performed to evaluate the SIEA origin, artery and vein pattern, vessel diameter, and dye diffusion territory. RESULTS: Overall, three SIEA patterns were identified: bilateral presence (45%), ipsilateral presence (30%), and bilateral absence (25%). The territory depended on the vessel course and dominant SIEA diameter, not on its common origin from the femoral artery, at the pubic tubercle level. Regarding the midline territory (pubic tubercle level to umbilicus), SIEA (type 1a) with a diameter of ≥1.4 mm on either side supplied at least half the distance, whereas SIEA with a diameter of <1 mm was limited to the suprapubic area. CONCLUSIONS: Designing a SIEA flap island across the midline is feasible when contralateral SIEA is present to augment the contralateral territory (e.g., type 1a SIEA) or in SIEA with a common/superficial external pudendal artery origin. Preoperative imaging studies are important for confirming the SIEA system. When the diameter at the origin of the SIEA flap is larger than 1.4 mm, the blood supply to the ipsilateral and contralateral sides is sufficient to enable safe flap elevation.

Anatomic Study of the Medial Collateral Ligament in Thai Population: A Cadaveric Study of 56 Elbows.

Purpose: This study aims to elucidate basic anatomic and geometric features of MCL, providing more accurate and detailed information, as guidance for surgeons, to improve patient's outcome of the treatment. Methods: The anterior bundle (AB), posterior bundle (PB) and transverse bundle (TB) ligament of 56 fresh frozen Thai cadaveric elbows, were measured and recorded, comprise key ligament's geometric features, footprints and dimensions, and its relation to bony landmarks. Sagittal and coronal planes were used in respect of the anatomical position. Results: The mean distance between the center of AB origin and the apex of medial epicondyle is as follows: 2.97 ± 2.21 mm anteriorly, 4.73 ± 1.60 mm inferiorly in the sagittal plane, and 4.23 ± 1.13 mm deep from the epicondyle in the coronal plane. Its dimension is 6.23 ± 1.02 mm in width and 45.97 ± 6.75 mm in length. The ligament's insertion triangular shape has its base located 28.44 ± 3.51 mm anterior from the posterior olecranon border, and 22.52 ± 2.49 mm superior from the inferior ulnar border. The tip located 50.79 ± 4.86 mm anterior from the posterior olecranon border and 17.64 ± 2.80 mm superior from the inferior ulnar border. Conclusion: Apprehension of the precise geometries and distances of the ligament's footprint relative to key anatomical point is crucial. This stereographically comprehended data are useful for surgeon as reference points to obtain stability, motion, kinetic, and kinematic properties of the elbow. Level of Evidence: Level V evidence. Supplementary Information: The online version contains supplementary material available at 10.1007/s43465-022-00648-x.

Efficacy of a perfused cadaver model for simulated trauma resuscitation in advanced surgical skills training.

BACKGROUND: To develop a perfused cadaveric model for trauma surgery simulation, and to evaluate its efficacy in trauma resuscitation advanced surgical skills training. METHODS: Fourteen fourth-year general surgery residents attended this workshop at Siriraj Hospital (Bangkok, Thailand). Inflow and outflow cannulae and a cardiopulmonary bypass pump were used to create the perfusion circuit. Inflow was achieved by cannulating the right common carotid artery, and outflow by cannulation of both the right common femoral artery and the internal jugular vein. Arterial line monitoring was used to monitor resuscitation response and to control perfusion pressure. The perfusion solution comprised saline solution mixed 1:1 with glycerol (50%) and water with red food dye added. Advanced surgical skills during life-threatening injuries and damage control resuscitation operations were practiced starting from the airway to the neck, chest, peripheral vessels, abdomen, and pelvis. Resuscitative endovascular balloon occlusion of the aorta (REBOA) was also practiced. Post-workshop survey questions were grouped into three categories, including comparison with previous training methods; the realism of anatomical correlation and procedures; and, satisfaction, safety, and confidence. All questions and tasks were discussed among all members of the development team, and were agreed upon by at least 90% of experts from each participating medical specialty/subspecialty. RESULTS: The results of the three main groups of post-workshop survey questions are, as follows: (1) How the training compared with previous surgical training methods-mean score: 4.26/5.00, high score: 4.73/5.00; (2) Realism of anatomical correlation and procedures-mean score: 4.03/5.00, high score: 4.60/5.00; and, (3) Satisfaction, safety, and confidence-mean score: 4.24/5.00, high score: 4.47/5.00. CONCLUSION: The developed perfused cadaveric model demonstrated potential advantages over previously employed conventional surgical training techniques for teaching vascular surgery at our center as evidenced by the improvement in the satisfaction scores from students attending perfused cadaveric training compared to the scores reported by students who attended earlier training sessions that employed other training techniques. Areas of improvement included 'a more realistic training experience' and 'improved facilitation of decision-making and damage control practice during trauma surgery'.

The lateral collateral ligament complex of the elbow in a Thai population: an anatomical study of 56 cadaveric specimens.

The purpose of this study was to investigate the anatomical features of the lateral collateral complex (LCC) of the elbow in a Thai population. We dissected 56 cadaveric elbows and described the LCC three-dimensionally in sagittal and coronal planes. We found that the characteristics differed from previous reports in other ethnic populations. In the sagittal plane, the centre of the origin of the LCC was located 3 mm anteriorly and 4 mm inferiorly to the apex of the lateral humerus epicondyle, and in the coronal plane it was 4 mm deep. The vertical distance between the origin of the lateral ulnar collateral ligament (LUCL) and the lateral epicondyle and the distance from the LUCL insertion to the border of the ulnar bone differed significantly between sexes. These data may be useful for surgeons during reconstruction of injures to the LCC of the elbow.Level of evidence: V.

Laparoscopic surgery produced less surgical smoke and contamination comparing with open surgery: the pilot study in fresh cadaveric experiment in COVID-19 pandemic.

BACKGROUND: The SARS-CoV2 virus has been identified in abdominal cavity of the COVID-19 patients. Therefore, the potential viral transmission from any surgical created smoke in these patients is of concern especially in laparoscopic surgery. This study aimed to compare the amount of surgical smoke and surgical field contamination between laparoscopic and open surgery in fresh cadavers. METHODS: Cholecystectomy in 12 cadavers was performed and they were divided into 4 groups: laparoscopic approach with or without smoke evacuator, and open approach with or without smoke evacuator. The increased particle counts in surgical smoke of each group were analyzed. In the model of appendectomy, surgical field contamination under ultraviolet light and visual contamination scale between laparoscopic and open approach were compared. RESULTS: Open cholecystectomy significantly produced a greater amount of overall particle sizes, particle sizes < 5 µm and particle sizes ≥ 5 µm than laparoscopic cholecystectomy (10,307 × 103 vs 3738 × 103, 10,226 × 103 vs 3685 × 103 and 81 × 103 vs 53 × 103 count/m3, respectively at p < 0.05). The use of smoke evacuator led to decrease in the amount of overall particle sizes of 58% and 32.4% in the open and laparoscopic chelecystectomy respectively. Median (interquatile range) visual contamination scale of surgical field in open appendectomy [3.50 (2.33, 4.67)] was significantly greater than laparoscopic appendectomy [1.50 (0.67, 2.33)] at p < 0.001. CONCLUSIONS: Laparoscopic cholecystectomy yielded less smoke-related particles than open cholecystectomy. The use of smoke evacuator, abeit non-significantly, reduced the particles in both open and laparoscopic cholecystectomy. Laparoscopic appendectomy had a lower degree of surgical field contamination than the open approach.

Surgical anatomy of vascularized submental lymph node flap: Sharing arterial supply of lymph nodes with the skin and topographic relationship with anterior belly of digastric muscle.

BACKGROUND AND OBJECTIVES: Development of vascularized submental lymph node (VSLN) flap has encountered dilemmas; (a) whether to include skin paddle, (b) how to reduce the harvest area while gaining most lymph nodes. To answer, these structures were studied; submental perforator, lymph nodes in neck-level I and anterior belly of digastric muscle (ABDM). METHODS: Forty VSLN flaps were harvested from 23 cadavers. The lymph nodes and arterial supply were studied macro- and microscopically. The nodes were classified by arterial supplies, location along the longitudinal axis and relationship with ABDM. RESULTS: VSLN flap had 4.4 lymph nodes by average (range 1-8) predominantly located in the posterior three-quarter of the flap. Half of the submental perforators were originated deep to ABDM. they circumvent the muscle, supplied much of the nodes in neck sublevel Ia before reaching the skin. While sublevel Ib located the most surgically accessible submental nodes. Most of their arterial supply was branched from submental perforator lateral to ABDM, not directly from the submental artery. CONCLUSION: The flap could be reduced to the posterior three-quarter of the original area. Skin paddle should be included to serve as an indirect lymph node monitor. If Ia lymph nodes are to be included, ABDM should be sacrified.

Effectiveness and Safety in Closed Mini-Transverse Incision with Hydro-Dissection Technique in Carpal Tunnel Release: A Cadaveric Study.

Background: Closed mini-wrist transverse incision for carpal tunnel release has been reported in decreasing surgical scar problems, but there were few cadaveric studies that proved the effectiveness and safety in this technique without protective instrument to the median nerve. Hydro-dissection was previously showed to separate median nerve and deep structures during percutaneous ultrasound guided transverse carpal ligament release. This cadaveric study aims to demonstrated effectiveness and safety of closed transverse carpal ligament (TCL) release though the mini-transverse incision at distal wrist crease combined with hydrodissection technique. Neither special instrument nor retractor was used to protect neurovascular structures. Methods: Twelve fresh frozen cadaveric wrists were included in this study. Completeness of TCL release and injury to the adjacent neurovascular structures were assessed by direct visualization. Thickness of TCL, TCL length and distance from incision to adjacent neurovascular structures were also recorded. Results: Complete release of TCL was demonstrated in all 12 (100%) wrists underwent the mini-transverse incision TCL release at distal wrist crease and hydro-dissection technique. No injury to the adjacent neurovascular structures was found in all 12 wrists. Mean of thickness of TCL and TCL length were 3 mm and 28.7 mm, respectively. The ulnar artery was the nearest structure to the incision (mean = 3.7 mm). Conclusions: The closed mini-transverse incision TCL release at distal wrist crease with hydro-dissection technique demonstrated completeness of TCL division and safety to the neurovascular structures without protecting retractor or special instrument.

Inferior External Pudendal Artery Anastomosis: Additional Approach to Prevent Skin Necrosis in Replanted Penis.

BACKGROUND: Microsurgical anastomosis of the dorsal artery of the penis either with or without anastomosis of the cavernosal artery is the preferred technique for penile replantation. However, postoperative penile skin necrosis is commonly reported with this technique. This study aimed to characterize the anatomy of the vascular supply of the penis pertinent to penile replantation surgery and to report a successful case of penile replantation without postoperative necrosis using anastomosis of the inferior external pudendal artery. METHODS: The authors dissected 15 penises of fresh cadavers under acrylic dye injection by means of the inferior external pudendal and dorsal arteries of the penis to identify vascular anastomoses between arteries supplying the penis and to measure other parameters of the arteries. RESULTS: Mean diameters at the base of the penis of the inferior external pudendal, dorsal, and cavernosal arteries were 0.94, 1.43, and 0.80 mm, respectively. Penile skin is mainly supplied by the inferior external pudendal artery under three patterns with anastomoses across the midline. Preputial skin receives additional blood supply from perforators of the dorsal artery without visible anastomosis between the perforators and the inferior external pudendal artery. Deep structures receive blood supply from the dorsal, cavernosal, and urethral arteries, with visible anastomoses between the arteries. In a patient with amputated penis, the inferior external pudendal artery diameter was 0.7 mm, which was sufficient for microsurgical anastomosis. No postoperative necrosis developed, and patency of the inferior external pudendal artery was confirmed with duplex ultrasound. CONCLUSION: The diameter of the inferior external pudendal artery at the base and midshaft of the penis is sufficiently large for microsurgical anastomosis, and additional vascular anastomosis of at least one inferior external pudendal artery may help to prevent postoperative penile skin necrosis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Anatomy of medial plantar superficial branch artery perforators: Facilitation of medial plantar superficial branch artery perforator (MPAP) flap harvesting and design for finger pulp reconstruction.

BACKGROUND: Medial plantar artery perforator (MPAP) flap was proposed as proper option for finger pulp reconstruction. To provide the previously unavailable vessel information required for this small flap design, this study aimed to gather all necessary anatomy of MPA, MPAP, and their territories of blood supply to apply in clinical MPAP flap reconstruction minimizing perforator injury. METHODS: Dissection of 30 Thai cadaveric feet for visualizing superficial branch of MPA and its perforators (MPAP) using acrylic dye cannulation were performed. Diameter, length, number of branches, course, distributing areas of these vessels, and also their areas of blood supply were recorded in relation to specified landmarks, eg, C-MTH line; medial calcaneal tuberosity to plantar side of the first metatarsal head and S point; emerging point of superficial branch of MPA from deep fasciae into subcutaneous layer. RESULTS: Average diameter of MPA at its origin and total length are 1.63 ± 0.3 and 52.8 ± 16.1 mm, respectively. It provides 1-3 perforators, with an average size and length of 0.36 ± 0.11 and 23.2 ± 5.47 mm, respectively. Its distribution is mostly in the posteromedial quadrant within 50 and 30 mm from the midpoint of C-MTH line and the S point, respectively. The estimated perforator flap area is 2.5 cm × 1.5 cm and 4.5 cm × 2.5 cm for single and double perforators, respectively. CONCLUSIONS: MPAP flap was proved as another ideal option for finger pulp reconstruction. Its limitation is small size of perforators but this can be overcome by using MPA for microsurgical anastomosis instead.

Vascular Nature and Existence of Anastomoses of Extrinsic Postauricular Fascia: Application for Staged Auricular Reconstruction.

A staged auricular reconstruction in microtia patients was developed by using superficial mastoid fascia (as part of extrinsic postauricular fascia) to cover the cartilagenous framework due to its highly vascularized nature. Three branches of external carotid artery (superficial temporal artery, posterior auricular artery and occipital artery) were found to supply this fascia, this study was therefore aimed to investigate the dimension of blood supply from each vessel and also to demonstrate the existence of anastomoses among these arteries. Thirty-eight pinnas and postauricular fascias from Thai fresh adult cadavers were included to document the anastomoses by showing both perfused dye connection (10 dissections) and visible anastomotic branches (8 dissections) among them. Distribution of each vessel trunk and its branches were demonstrated using superimposed illustration in the other 20 dissections with dye injection into each artery to designate 3 zones of anastomotic area between each arterial pair. Maximal size of viable postauricular fascial flap for staged reconstruction according to this vascular study was thus estimated to be at least 5 cm above and 3 cm below the Frankfurt horizontal plane and about 6 cm posterior to external acoustic meatus owing to the course of posterior auricular artery and its anastomoses. In addition, greater size of flap with dual blood supply from both superficial temporal and posterior auricular arteries can be raised by harvesting beyond 5 cm above external acoustic meatus.