Retroauricular lymph node flap: An anatomic and surgical feasibility study.

BACKGROUND: The study investigated the anatomy of the retroauricular lymph node (LN) flap and evaluate its surgical feasibility as a new donor site for a free LN flap in lymphedema surgery. METHODS: Twelve adult cadavers were examined. The course and perfusion of the anterior auricular artery (AAA) and the location and sizes of the retroauricular LNs were studied. RESULTS: The AAA was available in 87% and absent in 13% specimens. The AAA's origin had a mean vertical distance of 12.2 ± 6.9 mm and a mean horizontal distance of 19.1 ± 4.2 mm from the superior attachment of the ear. The mean diameter of the AAA was 0.8 ± 0.2 mm. The mean number of LN per region was 7.7 ± 2.3, with an average LN size of 4.1 ± 1.9 × 3.2 ± 1.7 mm. The LN were categorized into anterior (G1) and posterior (G2) groups, with a total of 59 and 10 LN, respectively. In a cluster analysis, three LN clusters could be detected across the anterior group (G1). CONCLUSIONS: The retroauricular LN flap is a delicate but feasible flap with reliable anatomy, containing a mean of 7.7 LNs.

Enhancing lymphangiogenesis and lymphatic drainage to vascularized lymph nodes with nanofibrillar collagen scaffolds.

BACKGROUND: This study investigated the effect of nanofibrillar collagen scaffold (BioBridge) implantation from the affected limb to the unaffected contralateral femoral vein or lymph node in a rat model. METHODS: Hind limb lymphedema in Lewis rats was created with lymphadenectomy and inguinal circumcision without radiation. The volumetric difference (greater than 5%) using computed tomography and indocyanine green fluorescence evaluated the progress of lymphedema at 4 weeks. The lymphedema rats have separated into Group I: Controls; Group II: implanted BioBridge to the contralateral femoral vein; and Group III: implanted BioBridge to the contralateral inguinal lymph node. RESULTS: A total of 14 of 30 (46.7%) rats developed hind limb lymphedema with a mean volume difference of 5.83 ± 0.99% and showed diffuse dermal backflow at 4 weeks postlymphadenectomy. Four weeks postimplantation of BioBridge, the mean volumetric difference was 5.62 ± 2.11%, 4.97 ± 0.59%, and -2.47 ± 2.37% in Group I, II, and III, respectively (p < 0.05). The dermal backflow on the affected limb increased in Groups I and II but decreased in Group III. CONCLUSIONS: Implantation of BioBridge from the affected limb to the contralateral inguinal lymph node significantly reduced the hind limb lymphedema at 4 weeks.

Long-term outcomes of arterial ischemia or venous occlusion on vascularized groin lymph nodes in a rat model.

BACKGROUND: This study investigated the long-term effects of arterial ischemia and venous occlusion on lymph node drainage function in a rat model. METHODS: Bilateral groin lymph node flaps of 18 Lewis rats were dissected. The pedicle artery was clamped for 4, 5, and 6 h (A4, A5, and A6 groups), and the vein for 3, 4, and 5 h (V3, V4, and V5 groups) in six flaps. At 4 weeks, the evaluations included gross morphomics, indocyanine green (ICG) lymphography, histological section, immunofluorescence of terminal deoxynucleotidyl transferase assay, and heme oxygenase-1 (HO-1) stain. RESULTS: The lymph node flaps developed shrinkage and partial necrosis in A5, A6, V4, and V5 groups. Hemorrhage in the lymph node cortex and medulla was observed histologically in A5, A6, and V5 groups. ICG lymphography showed loss of lymphatic drainage function in 2 of 6 flaps in A6 and V5 groups. Cell death was shown partly in cortical follicles in A5 and V4 groups and completely in A6 and V5 groups. The HO-1 expression was statistically increased in A5 and V5 groups, respectively (p < 0.05). CONCLUSIONS: The critical arterial ischemia and venous occlusion time were 4 h at 4 weeks of follow-up.

"Double Barrel" Lymphaticovenous Anastomosis: A Useful Addition to a Supermicrosurgeon's Repertoire.

Microsurgical amelioration of lymphedema has gained much traction in recent years and is now an established modality of treatment for this condition. Despite the development of many newer techniques, lymphaticovenous anastomosis still remains the most frequently carried out microsurgical procedure for lymphedema. One of the most common hurdles faced by lymphatic surgeons while carrying out a lymphaticovenous anastomosis is a mismatch in sizes of the vein and the lymphatic vessels. Method: This article describes a novel but simple "double barrel" technique, developed by the authors for carrying out lymphaticovenous anastomosis in cases of such lymphaticovenous mismatch. Seventeen double barrel anastomoses were carried out in 12 lymphedema patients, over a 4-year period from 2017 to 2021. Results: The overall success rate was 100%, as measured by clinical observation (venous washout, lymphatic backflow), the Acland vessel strip test, and by means of intraoperative ICG lymphography. Mild leakage was observed in four cases after release of the venous clamp and was corrected by application of additional sutures. Conclusions: The double barrel technique is a safe and effective tool that can be employed to deal with the bane of size mismatch, a persistent problem faced by lymphedema surgeons universally. Although we do not advocate it as a total replacement for other techniques, it can be a worthy addition to the present set of available options. In specific scenarios of mismatch with additional challenges, the double barrel technique has the potential to be considered as primus inter pares.

Occult Pathologic Findings in Reduction Mammaplasty in 5781 Patients-An International Multicenter Study.

Breast cancer is among the most commonly diagnosed cancers in the world, affecting one in eight women in their lifetimes. The disease places a substantial burden on healthcare systems in developed countries and often requires surgical correction. In spite of this, much of the breast cancer pathophysiology remains unknown, allowing for the cancer to develop to later stages prior to detection. Many women undergo reduction mammaplasties (RM) to adjust breast size, with over 500,000 operations being performed annually. Tissue samples from such procedures have drawn interest recently, with studies attempting to garner a better understanding of breast cancer's development. A number of samples have revealed nascent cancer developments that were previously undetected and unexpected. Investigating these so-called "occult" findings of cancer in otherwise healthy patients may provide further insight regarding risk factors and countermeasures. Here, we detail occult findings of cancer in reduction mammaplasty samples provided from a cohort of over 5000 patients from 16 different institutions in Europe. Although the majority of our resected breast tissue specimens were benign, our findings indicate that there is a continued need for histopathological examination. As a result, our study suggests that preoperative imaging should be routinely performed in patients scheduled for RM, especially those with risk factors of breast cancer, to identify and enable a primary oncologic approach.

Impacts of arterial ischemia or venous occlusion on vascularized groin lymph nodes in a rat model.

BACKGROUND: Reported ischemia time of vascularized lymph nodes was 5 hours. This study investigated the effects of arterial ischemia and venous occlusion on vascularized lymph node function in rats. METHODS: Bilateral pedicled groin lymph node flaps were raised in 27 Lewis rats. Femoral artery and vein were separated and clamped for 1, 3, 4, or 5 hour(s). Lymph node flap perfusion and drainage were assessed by laser Doppler flowmetry and indocyanine green lymphography. Histologic changes were assessed using hematoxylin and eosin stain, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), and glutathione assays. RESULTS: Perfusion units of 2.84 ± 1.41, 2.46 ± 0.64, 2.42 ± 0.37, and 2.01 ± 0.90 were measured in arterial ischemia groups, and 1.71 ± 0.45, 2.20 ± 0.98, 1.49 ± 0.35, and 0.81 ± 0.20 in venous occlusion groups after 1, 3, 4, and 5 hours of clamping, respectively. Lymphatic drainage showed mean latency periods of 5.33 ± 0.88, 9.00 ± 3.21, 10.00 ± 2.08, and 24.50 ± 11.50 seconds in arterial clamping groups, and 25.00 ± 3.61, 26.00 ± 3.06, 23.33 ± 4.41, and 152.00 ± 0 seconds in venous clamping groups, respectively. Severe medullary and cortical congestion and hemorrhage on histology and cell damage by glutathione levels and TUNEL assay were found after 4 hours of venous clamping. CONCLUSIONS: Arterial ischemia and venous occlusion impact the function and viability of vascularized lymph node flaps differently. The critical venous occlusion time was 4 hours.

A Head-to-Head Comparison of the Vascular Basis of the Transverse Myocutaneous Gracilis, Profunda Artery Perforator, and Fasciocutaneous Infragluteal Flaps: An Anatomical Study.

BACKGROUND: Perforator flaps of the upper thigh or buttock provide a valuable secondary choice in autologous breast reconstruction. The purpose of this study was to compare the vascular territories and supplying vessels of the transverse myocutaneous gracilis flap, the profunda artery perforator flap, and the fasciocutaneous infragluteal flap. METHODS: In total, 26 lower limbs from 13 fresh specimens were investigated. All flap pedicles were selectively injected with methylene blue, eosin red, or green ink. The pedicle external diameters, lengths, and locations were measured. The dimensions of angiosomes, their intraindividual and interindividual correlations, and their relations to anatomical landmarks were analyzed. RESULTS: The profunda artery perforator pedicle had the greatest mean external diameter with 3.6 ± 0.7 mm, followed by the transverse myocutaneous gracilis and fasciocutaneous infragluteal pedicles with 2.9 ± 0.6 mm and 2.9 ± 0.7 mm, respectively. The fasciocutaneous infragluteal pedicle was longest with a mean length of 12.5 ± 1.5 cm, whereas the profunda artery perforator and transverse myocutaneous gracilis pedicles had lengths of 8.8 ± 1.0 cm and 6.7 ± 1 cm on average. The profunda artery perforator angiosome provided the largest size, with a mean area of 98.5 ± 26.7 cm(2), followed by the fasciocutaneous infragluteal angiosome (77.2 ± 9.0 cm(2)) and the transverse myocutaneous gracilis angiosome (74.1 ± 32.1 cm(2)). CONCLUSIONS: The authors' anatomical findings about the transverse myocutaneous gracilis, profunda artery perforator, and fasciocutaneous infragluteal territories provide clinically valuable data for flap selection in breast reconstruction if an abdominal flap is not feasible.

Superficial Circumflex Iliac Artery Perforator Flap: An Anatomical Study of the Correlation of the Superficial and the Deep Branches of the Artery and Evaluation of Perfusion from the Deep Branch to the Sartorius Muscle and the Iliac Bone.

BACKGROUND: Harvesting the sartorius muscle and the iliac bone with a superficial circumflex iliac artery (SCIA) perforator flap can be a challenging procedure. The aim of this study was to describe the anatomical topology of the deep branch of the SCIA in fresh cadavers, which has not been reported in detail. METHODS: Twenty groin regions from 10 fresh cadavers were dissected. The characteristics and landmarks of the SCIA system, including branches to the sartorius muscle and the iliac bone, were examined. Perfusion of the sartorius muscle and the iliac bone by means of the deep branch of the SCIA was evaluated with indocyanine green angiography and computed tomographic angiography. RESULTS: The superficial and the deep branches were identifiable in all specimens. In 85 percent of the specimens, the bifurcation point could be seen within 2 cm from a fixed site: 6 cm from the pubic tubercle to the anterior superior iliac spine, and 3 cm caudal from that point. The deep branch in each case gave off branches to the sartorius muscle and the iliac bone. The cephalad portion of the sartorius muscle (up to 8 cm from the anterior superior iliac spine) and the superficial portion of the iliac bone (up to 1.5 cm from the iliac crest) were perfused by the deep branch of the SCIA. CONCLUSIONS: In all specimens, both the superficial branch and the deep branch of the SCIA were found. The deep branch was found consistently to give off perfusing branches to the sartorius muscle and the iliac bone.

The dermal arteries in the cutaneous angiosome of the descending genicular artery.

Studies examining thick skin of the thumb pad have challenged the existence of an arterial plexus in the papillary dermis. Instead of a plexus, discrete arterial units, interconnected by arterio-arterial anastomoses, were identified. We hypothesise that the dermal arteries of thin skin are arranged likewise and that there are fewer arterio-arterial anastomoses in the centre of an angiosome than in zones where neighbouring angiosomes overlap. To test these hypotheses, we examined the dermal arteries in the centre of the cutaneous angiosome of the descending genicular artery (DGA) and its zone of overlap with neighbouring angiosomes. Using traditional perfusion techniques, the cutaneous angiosomes of the DGA and the popliteal artery were identified in 11 fresh frozen human lower limbs. Biopsies were harvested from the centre of the cutaneous DGA angiosome and from the zone where neighbouring vascular territories overlapped. Employing high-resolution episcopic microscopy (HREM), digital volume data were generated and the dermal arteries were three-dimensionally reconstructed and examined. In all examined skin areas, the dermal arteries showed tree-like ramifications. The branches of the dermal arteries were connected on average by 1.73 ± 1.01 arterio-arterial anastomoses in the centre of the DGA angiosome and by 3.27 ± 1.27 in the zone where angiosomes overlapped. We demonstrate that discrete but overlapping dermal arterial units with a mean dimension of 1.62 ± 1.34 and 1.80 ± 1.56 mm2 , respectively, supply oxygen and nutrients to the superficial dermis and epidermis of the thin skin of the medial femur. This forms the basis for diagnosing and researching skin pathologies.

Feasibility of Bone Perfusion Evaluation in Cadavers Using Indocyanine Green Fluorescence Angiography.

Bone perfusion evaluation methods in cadaver studies have yet to be established. The aim of this report was to introduce and validate the feasibility of indocyanine green (ICG) fluorescence angiography for evaluation of bone perfusion in the femoral medial condyle in cadavers. In 4 fresh nonembalmed cadavers (2 female), the descending genicular artery was dissected and carefully cannulated bilaterally. A 10 mL solution containing 5 mL ICG solution and 5 mL methylene blue solution was injected into the descending genicular artery. After the injection, the medial femoral condyle was cut with an oscillating saw. A photograph was taken of the cut ends of the bone. The cut ends of the bones were observed using a near-infrared camera. Images corresponding to the previously taken photographs of the cut ends were captured for comparative analysis. After injection of methylene blue and ICG, the blue dye could be seen in the periosteum in all specimens, but not inside the cortex or the cancellous region of the bone. When observed with ICG fluorescence angiography, however, the cancellous region was highlighted through small perforators penetrating the periosteum. Perfusion inside the medial femoral condyle in cadavers was confirmed using ICG fluorescence angiography. Our method can be especially beneficial in confirming the bone perfusion of a new bone flap based on a particular artery, both in cadavers as well as in patients, because ICG can be injected into specific arteries.

The surgical anatomy of the vascularized lateral thoracic artery lymph node flap-A cadaver study.

BACKGROUND: One promising surgical treatment of lymphedema is the VLNT. Lymph nodes can be harvested from different locations; inguinal, axillary, and supraclavicular ones are used most often. The aim of our study was to assess the surgical anatomy of the lateral thoracic artery lymph node flap. MATERIALS AND METHODS: In total, 16 lymph node flaps from nine cadavers were dissected. Flap markings were made between the anterior and posterior axillary line in dimensions of 10 × 5 cm. Axillary lymph nodes were analyzed using high-resolution ultrasound and morphologically via dissection. The cutaneous vascular territory of the lateral thoracic artery was highlighted via dye injections, the pedicle recorded by length, and diameter and its location in a specific coordinate system. RESULTS: On average, 3.10 ± 1.6 lymph nodes were counted per flap via ultrasound. Macroscopic inspection showed on average 13.40 ± 3.13. Their mean dimensions were 3.76 ± 1.19 mm in width and 7.12 ± 0.98 mm in length by ultrasonography, and 3.83 ± 2.14 mm and 6.30 ± 4.43 mm via dissection. The external diameter of the lateral thoracic artery averaged 2.2 ± 0.40 mm with a mean pedicle length of 3.6 ± 0.82 cm. 87.5% of the specimens had a skin paddle. CONCLUSIONS: The lateral thoracic artery-based lymph node flap proved to be a suitable alternative to other VLNT donor sites.

The surgical anatomy of the supraclavicular lymph node flap: A basis for the free vascularized lymph node transfer.

BACKGROUND: Vascularized lymph node transfer is an effective surgical method in reducing lymphedema. This study provides the first detailed description of the surgical anatomy of the supraclavicular lymph node flap in regard to pedicle length, pedicle diameter, and the number of lymph nodes and their exact location inside the flap. METHODS: Bilateral supraclavicular dissections of nine fresh cadavers (five female) were performed. Before the dissection, the exact number of lymph nodes was determined sonographically by an experienced radiologist, and their distance from the jugular notch was measured. After anatomic dissection, the vascular pedicle's diameter and length were measured. RESULTS: The mean number of lymph nodes was 1.5 ± 1.85 on the right side and 3 ± 2.26 on the left. Their mean distance from the jugular notch was 8.29 ± 2.15 cm on the right and 6.10 ± 1.21 cm on the left. The pedicle's length was 4.72 ± 1.03 cm on the right and 4.86 ± 0.99 cm on the left, and its diameter 2.03 ± 0.83 on the right and 1.80 ± 0.77 on the left. CONCLUSION: The pedicle length and diameter of the supraclavicular lymph node flap are suitable for a microvascular tissue transfer. J. Surg. Oncol. 2017;115:60-62. © 2016 Wiley Periodicals, Inc.

Vascular territories of the medial upper arm-an anatomic study of the vascular basis for individualized flap design.

BACKGROUND: Fasciocutaneous flaps supplied by discrete perforator arteries can be raised in numerous parts of the human body and are routinely used in plastic surgery. The aim of this anatomical investigation was to provide a description of the vascular supply of the medial upper arm, to localize and measure the perforator arteries and to define potential perforator flap dimensions in pendency of individual anatomical conditions. MATERIAL AND METHODS: A total of 20 upper limbs from 11 fresh cadavers were examined. The brachial arteries were exposed and the medial perforator arteries selectively injected with methylene blue and india ink in an alternating sequence. The size of the angiosomes, the diameter and length of the perforators' pedicles and distances between the arteries and the medial epicondyle and apex of the axilla respectively were measured. RESULTS: On average, 4.55 ± 1.47 perforating arteries arose from the brachial artery and it's medial off branching arteries. Their mean diameter was 0.68 ± 0.27 mm and their pedicles had an average length of 3.62 ± 1.61 cm measured from suprafascial until arborisation. In 80% the first proximal perforator was present in an area of 4 cm radius at centre coordinates of (20/2). A constant distal perforator was found within a circle of 3 cm radius, of which the centre had the coordinates (8/1). The average size of the angiosomes was 121.1 ± 58.5 cm2 . Direct branches of the brachial artery feed circular shaped vascular territories, whereas superior ulnar collateral arteries (SUCAs) feed oblong shaped territories. CONCLUSION: This anatomical study provides valuable data of the medial arm flap in order to be applied clinically. © 2016 Wiley Periodicals, Inc.

High-resolution episcopic microscopy (HREM): a useful technique for research in wound care.

Analysing the three-dimensional (3D) texture of skin substitute materials and evaluating their performance after covering skin defects is essential for improving their design and for optimising surgical procedures and post implantation wound treatment regimes. Here we explore the capacities of the recently developed High-resolution episcopic microscopy (HREM) method for generating digital volume data that permit structural 3D analysis of native and implanted collagen-elastin matrices. We employed HREM to visualise native collagen matrices and collagen matrices seeded with keratinocytes. In a second step, we visualised the appearance and the revascularisation of the matrices after their implantation beneath split skin grafts used for covering skin defects in the porcine model. For this, HREM data were generated from biopsies harvested 5, 10, and 15 days after surgery. In all instances, the high quality and resolution of the HREM data in combination with the relative large field of view proved to be sufficient for visualizing the exact fibre architecture by employing quick volume rendering algorithms. Precise analysis of the 3D distribution of keratinocytes in the matrices populated with keratinocytes and of the detailed topology of the sprouting blood vessels in the implanted matrices was feasible. Our results show that high-resolution episcopic microscopy can be adapted to serve as a tool for evaluating collagen-elastin materials ex- and in vivo.

Simultaneous dermal matrix and autologous split-thickness skin graft transplantation in a porcine wound model: a three-dimensional histological analysis of revascularization.

Despite the popularity of a simultaneous application of dermal matrices and split-thickness skin grafts, scarce evidence exists about the process of revascularization involved. In this study, we aimed at analyzing the progression of revascularization by high-resolution episcopic microscopy (HREM) in a porcine excisional wound model. Following the surgical procedure creating 5 × 5 cm(2) full-thickness defects on the back, one area was covered with an autologous split-thickness skin graft alone (control group), the other with a collagen-elastin dermal matrix plus split-thickness skin graft (dermal matrix group). Two skin biopsies per each group and location were performed on day 5, 10, 15, and 28 postoperatively and separately processed for H&E as well as HREM. The dermal layer was thicker in the dermal matrix group vs. control on day 5 and 28. No differences were found for revascularization by conventional histology. In HREM, the dermal matrix did not appear to decelerate the revascularization process. The presence of the dermal matrix could be distinguished until day 15. By day 28, the structure of the dermal matrix could no longer be delineated and was replaced by autologous tissue. As assessed by conventional histology and confirmed by HREM, the revascularization process was comparable in both groups, notably with regard to the vertical ingrowth of sprouting vessels. The presented technique of HREM is a valuable addition for analyzing small vessel sprouting in dermal matrices in the future.

High-resolution episcopic microscopy (HREM): a tool for visualizing skin biopsies.

We evaluate the usefulness of digital volume data produced with the high-resolution episcopic microscopy (HREM) method for visualizing the three-dimensional (3D) arrangement of components of human skin, and present protocols designed for processing skin biopsies for HREM data generation. A total of 328 biopsies collected from normally appearing skin and from a melanocytic nevus were processed. Cuboidal data volumes with side lengths of ~2×3×6 mm3 and voxel sizes of 1.07×1.07×1.5 µm3 were produced. HREM data fit ideally for visualizing the epidermis at large, and for producing highly detailed volume and surface-rendered 3D representations of the dermal and hypodermal components at a structural level. The architecture of the collagen fiber bundles and the spatial distribution of nevus cells can be easily visualized with volume-rendering algorithms. We conclude that HREM has great potential to serve as a routine tool for researching and diagnosing skin pathologies.