Fate of Costochondral Grafts for Micrognathia: 3D Analysis of Postoperative Length, Position, and Graft Take.

PURPOSE: Costochondral grafting is performed in the reconstruction of severe micrognathia. In this study, we report our experience with graft take, as well as unique findings that have not been focused on in the past literature such as postoperative position and changes in the shape of the graft and thinning of the skull base in contact with the graft. METHODS: Between 2002 and 2019, costochondral grafting was performed on 15 sides of 10 patients with micrognathia. Graft take and other detailed findings such as growth, position, and changes in the shape of the grafts and skull base in contact with the grafts were evaluated using computed tomography images. RESULTS: Graft take was obtained in all cases, and subsequent distraction could be performed in 8 of 10 graft sites as planned. Six of 15 grafts were displaced anterior to the preoperative planned position. However, there were no cases with complications due to deviation such as trismus. Concave deformity of the skull base in contact with the graft was observed in 9 graft sites. The thinning and bending deformation were observed in 2 grafts. CONCLUSIONS: Costochondral grafting was considered a reasonable method for first-line treatment of severe micrognathia. Several unique findings that have not been focused on in the past literature were observed. These should be kept in mind when performing costochondral grafting. Several modifications to the present protocol are suggested to improve the quality of graft take.

Evaluation of the effect of age of the younger mice on the rejuvenation of the older mice by heterochronic parabiosis.

Heterochronic parabiosis is used to study the systemic effects of aging and involves surgically connecting two animals of different ages such that they have common blood circulation. Although this technique has been prevalent for a long time, there is no scientific consensus on the age of the animals that should be used. We hypothesized that the younger the animal, the greater would be its rejuvenating effect. Hence, to test this hypothesis, we created parabiosis of 67-week-old mice with younger mice of different ages (4-week-old and 8-week-old). We evaluated the changes in appearance and the expression IL-1A, IL-6, and Cdkn2a (p16) in the liver, kidney, brain, and skin. These cytokines belong to the senescence-associated secretory phenotype (SASP) factors, and are indicators of aging. Although we did not find any significant changes in the appearance of the mice, we found statistically significant differences in some SASP factors between the liver of the 4-week-old and 8-week-old pairs. However, overall, compared to the 8-week-old mice, the 4-week-old does not exert a significantly higher rejuvenation effect on the older mice. Hence, we concluded that the rejuvenation of older mice during heterochronic parabiosis might not be affected by the exact age of the younger mice.

Photoacoustic lymphangiography before and after lymphaticovenular anastomosis.

BACKGROUND: Lymphaticovenular anastomosis (LVA) is a minimally invasive surgical procedure used to treat lymphedema. Volumetric measurements and quality-of-life assessments are often performed to assess the effectiveness of LVA, but there is no method that provides information regarding postoperative morphological changes in lymphatic vessels and veins after LVA. Photoacoustic lymphangiography (PAL) is an optical imaging technique that visualizes the distribution of light-absorbing molecules, such as hemoglobin or indocyanine green (ICG), and provides three-dimensional images of superficial lymphatic vessels and the venous system simultaneously. In this study, we performed PAL in lymphedema patients before and after LVA and compared the images to evaluate the effect of LVA. METHODS: PAL was performed using the PAI-05 system in three patients (one man, two women) with lymphedema, including one primary case and two secondary cases, before LVA. ICG fluorescence lymphography was performed in all cases before PAL. Follow-up PAL was performed between 5 days and 5 months after LVA. RESULTS: PAL enabled the simultaneous visualization of clear lymphatic vessels that could not be accurately seen with ICG fluorescence lymphography and veins. We were also able to observe and analyze morphological changes such as the width and the number of lymphatic vessels and veins during the follow-up PAL after LVA. CONCLUSIONS: By comparing preoperative and postoperative PAL images, it was possible to analyze the morphological changes in lymphatic vessels and veins that occurred after LVA. Our study suggests that PAL would be useful when assessing the effect of LVA surgery.

Micro-arteriovenous fistula in patients with lower limb lymphedema.

BACKGROUND: A micro-arteriovenous fistula (AVF) is a minute, short shunt between an artery and a vein that does not pass through a capillary. We investigated the association between micro-AVFs and lymphedema using computed tomography angiography (CTA) and venous blood gas analysis. METHODS: In 95 patients with lower limb lymphedema, the presence or absence of early venous return (EVR) was compared between patients with primary and secondary lymphedema. Furthermore, we investigated the difference in the timing of edema onset in patients with secondary lymphedema with or without EVR using CTA. In 20 patients with lower limb lymphedema with confirmed early EVR in a unilateral lower limb, the partial pressure of oxygen (PO2) was compared between the lower limb with EVR and the contralateral lower limb. RESULTS: Secondary lymphedema with or without EVR occurred at an average of 36.0±59.3 months and 93.5±136.1 months, respectively; however, no significant difference was noted. PO2 was 57.6±11.7 mmHg and 44.1±16.4 mmHg in the EVR and non-EVR limbs, respectively, which was a significant difference (P=0.005). CONCLUSIONS: EVR and venous blood gas analysis suggested the presence of micro-AVFs in patients with lower extremity edema. Further research is warranted to examine the cause of micro-AVFs, to advance technology to facilitate the confirmation of micro-AVFs by angiography, and to improve lymphedema by ligation of micro-AVFs.

The Direct Observation of Lymphaticovenular Anastomosis Patency with Photoacoustic Lymphangiography.

It is difficult to evaluate the postoperative patency of lymphaticovenular anastomosis, but this evaluation is essential for determining surgical results. When using the current standard modality, near-infrared fluorescent lymphography, it is difficult to observe patency if the anastomotic point is veiled by dermal backflow. In this study, we used a new photoacoustic imaging device, PAI-05, to check the patency of anastomosis. We performed photoacoustic lymphangiography after lymphaticovenular anastomosis surgery. By digitally subtracting the superficial area, we can examine an area deeper than the dermal backflow, which is not visible by near-infrared fluorescent lymphography. The connection between the lymphatic vessel and the venule observed in the image is an indication of the patency of anastomosis. However, in a non-patent anastomosed site, the lymphatic vessel has a gap that separates it from the venule at the anastomosed site. Although photoacoustic lymphangiography cannot be used to visualize the lymphatic vessels that are not contrasted by indocyanine green, the resulting high-resolution images and clear anastomosis evaluation afforded by it will contribute to the development of future lymphedema treatments.

The Internal Oblique Muscle Flap with Synthetic Mesh Reinforcement for a Large, Contaminated Abdominal Wall Defect.

We report a case of a large mediocaudal abdominal defect in contaminated circumstances with no residual rectus abdominis muscle that was reconstructed using an internal oblique muscle flap with large-pore polypropylene mesh reinforcement. The internal oblique muscle flap can reconstruct the lower abdominal midline without leaving any additional conspicuous scar. Previous studies showed that large-pore polypropylene mesh in contaminated wounds has a minimal difference in terms of infection rate, and less frequent occurrence of hernia, compared even with biological meshes. We believe that this method could be a strong and cosmetically satisfying option for large mediocaudal abdominal wall reconstruction.

Effective combination of lymphatico-venous anastomosis and negative pressure wound therapy for lymphocyst: A Case Study.

Lymphorrhea and lymphocysts are complications that occur after lymph node dissection or biopsy and are difficult to treat. Conventional treatments for lymphocysts are not always effective. For instance, lymphatico-venous anastomosis has a limited treatment efficacy when the cyst wall is thickened, and negative pressure wound therapy is limited by the installation site and longer treatment times. To overcome these individual shortcomings, we aimed to assess whether a combination of both interventions would be effective. In this study, we report the application of a lymphatico-venous anastomosis combined with negative pressure wound therapy for treating bilateral inguinal lymph nodes and pelvic lymph node dissection following treatment of vaginal cancer. Short-term improvements were observed with no recurrence of lymphocysts at 1-year follow-up.

A Novel Surgical Approach for Refractory Secondary Lymphedema of the Lower Extremity Accompanying Micro-Arteriovenous Fistula.

Lymphaticovenous anastomosis (LVA) for lymphedema of the lower extremity has been established as a minimally invasive and effective surgical treatment to return static lymph fluid to the vein. However, we often experience cases in which the effect of LVA cannot be obtained sufficiently, or the anastomotic site becomes obstructed and the edema deteriorates over a long term. One of the causes is the combination of local venous hypertension (VT) by micro-arteriovenous fistula (mAVF). We report two cases of refractory lymphedema at the lower extremity caused by mAVF and incompetent perforating vein (IPV). In these cases, surgical ligation and separation of the mAVF and IPV is effective in reducing edema.

A simple calculation for the preoperative estimation of transverse rectus abdominis myocutaneous free flap volume in 2-stage breast reconstruction using a tissue expander.

BACKGROUND: Flap volume is an important factor for obtaining satisfactory symmetry in breast reconstruction with a transverse rectus abdominis myocutaneous (TRAM) free flap. We aimed to develop an easy and simple method to estimate flap volume. METHODS: We performed a preoperative estimation of the TRAM flap volume in five patients with breast cancer who underwent 2-stage breast reconstruction following an immediate tissue expander operation after a simple mastectomy. We measured the height and width of each flap zone using a ruler and measured the tissue thickness by ultrasound. The volume of each zone, approximated as a triangular or square prism, was then calculated. The zone volumes were summed to obtain the total calculated volume of the TRAM flap. We then determined the width of zone II, so that the calculated flap volume was equal to the required flap volume (1.2×1.05×the weight of the resected mastectomy tissue). The TRAM flap was transferred vertically so that zone III was located on the upper side, and zone II was trimmed in the sitting position after vascular anastomosis. We compared the estimated flap width of zone II (=X) with the actual flap width of zone II. RESULTS: X was similar to the actual measured width. Accurate volume replacement with the TRAM flap resulted in good symmetry in all cases. CONCLUSIONS: The volume of a free TRAM flap can be straightforwardly estimated preoperatively using the method presented here, with ultrasound, ruler, and simple calculations, and this technique may help reduced the time required for precise flap tailoring.