Methodological rigour in preclinical urology: a systematic review reporting research quality over a 14-year period.

OBJECTIVE: To investigate the prevalence and trends of essential study design elements in preclinical urological studies, as well as key factors that may improve methodological rigour, as the demand for methodological rigour in preclinical studies is increasing since research reproducibility and transparency in the medico-scientific field are being questioned. METHODS AND RESULTS: PubMed was searched to include preclinical urological studies published between July 2007 to June 2021. A total of 3768 articles met the inclusion criteria. Data on study design elements and animal models used were collected. Citation density was also examined as a surrogate marker of study influence. We performed an analysis of the prevalence of seven critical study design elements and temporal patterns over 14 years. Randomisation was reported in 50.0%, blinding in 15.0%, sample size estimation in 1.0%, inclusion of both sexes in 6.3%, statistical analysis in 97.1%, housing and husbandry in 47.7%, and inclusion/exclusion criteria in 5.0%. Temporal analysis showed that the implementation of these study design elements has increased, except for inclusion of both sexes and inclusion/exclusion criteria. Reporting study design elements were associated with increased citation density in randomisation and statistical analysis. CONCLUSIONS: The risk of bias is prevalent in 14-year publications describing preclinical urological research, and the quality of methodological rigour is barely related to the citation density of the article. Yet five study design elements (randomisation, blinding, sample size estimation, statistical analysis, and housing and husbandry) proposed by both the National Institutes of Health and Animal Research: Reporting of In Vivo Experiments guidelines have been either well reported or are being well reported over time. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022233125.

Analysis of flap thickness to breast projection ratio correlating to body mass index and age in east Asian women: Considerations in flap selection in breast reconstruction.

BACKGROUND: Several alternative flaps have been introduced and used for autologous breast reconstruction. However, as body fat distribution is different among patients, the donor of choice for sufficient breast projection varies between patients. METHODS: Patients who underwent autologous breast reconstruction from Jan 2018 to Sep 2022 were included. Age, body mass index (BMI), smoking history and hypertension, and diabetes occurrence were collected as baseline demographic data. Breast projection with five types of flap thickness was measured based on computed tomography angiography. Analysis was performed for five major autologous flaps for breast reconstruction. RESULTS: A total of 563 patients were included in the study. The mean age of the patients was 47.4 ± 7.9 (standard deviation; SD) years. The mean BMI of the patients was 24.0 ± 3.4 kg/m2. Only the correlation between flap thickness to breast projection ratio and age in the PAP flap illustrated statistical significance (p = .039), but the correlation coefficient was quite low (r = -0.087). Slim patients who had lower BMIs (under 25 kg/m2) had significantly higher sufficient flap thickness for breast reconstruction than patients with higher BMIs over 25 kg/m2 in the profunda artery perforator (PAP) flap (p < .001), the lumbar artery perforator (LAP) flap (p < .001), and the superior gluteal artery perforator (SGAP) flap (p < .001). CONCLUSIONS: The deep inferior epigastric perforator flap provided sufficient thickness and was not usually affected by age and BMI. The PAP, LAP, and SGAP flaps tended to maintain the thickness of the flap even when BMI decreased, so they are advantageous for reconstruction in slim patients. This study contributes evidence in consideration of flap selection in autologous breast reconstruction.

The Effect of 3-Dimensional-Printed Sequential Dual Drug-Releasing Patch on the Capsule Formation Around the Silicone Implant in a Rat Model.

BACKGROUND: Implant-based breast reconstruction is associated with increased risk of early infection and late-stage capsular contracture. OBJECTIVES: We evaluated the feasibility of a dual drug-releasing patch that enabled the controlled delivery of antibiotics and immunosuppressants in a temporally and spatially appropriate manner to the implant site. METHODS: The efficacy of a dual drug-releasing patch, which was 3-dimensional-printed (3D-printed) with tissue-derived biomaterial ink, was evaluated in rats with silicone implants. The groups included implant only (n = 10); implant plus bacterial inoculation (n = 14); implant, bacterial inoculation, and patch loaded with gentamycin placed on the ventral side of the implant (n = 10), and implant, bacterial inoculation, and patch loaded with gentamycin and triamcinolone acetonide (n = 9). Histologic and immunohistochemical analyses were performed 8 weeks after implantation. RESULTS: The 2 drugs were sequentially released from the dual drug-releasing patch and exhibited different release profiles. Compared to the animals with bacterial inoculation, those with the antibiotic-only and the dual drug-releasing patch exhibited thinner capsules and lower myofibroblast activity and inflammation, indicating better tissue integration and less foreign body response. These effects were more pronounced with the dual drug-releasing patch than with the antibiotic-only patch. CONCLUSIONS: The 3D-printed dual drug-releasing patch effectively reduced inflammation and capsule formation in a rat model of silicone breast reconstruction. The beneficial effect of the dual drug-releasing patch was better than that of the antibiotic-only patch, indicating its therapeutic potential as a novel approach to preventing capsular contracture while reducing concerns of systemic side effects.

Deciphering the Role of ERBB3 Isoforms in Renal Cell Carcinoma: A Comprehensive Genomic and Transcriptomic Analysis.

ERBB3, a key member of the receptor tyrosine kinase family, is implicated in the progression and development of various human cancers, affecting cellular proliferation and survival. This study investigated the expression of ERBB3 isoforms in renal clear cell carcinoma (RCC), utilizing data from 538 patients from The Cancer Genome Atlas (TCGA) Firehose Legacy dataset. Employing the SUPPA2 tool, the activity of 10 ERBB3 isoforms was examined, revealing distinct expression patterns in RCC. Isoforms uc001sjg.3 and uc001sjh.3 were found to have reduced activity in tumor tissues, while uc010sqb.2 and uc001sjl.3 demonstrated increased activity. These variations in isoform expression correlate with patient survival and tumor aggressiveness, indicating their complex role in RCC. The study, further, utilizes CIBERSORTx to analyze the association between ERBB3 isoforms and immune cell profiles in the tumor microenvironment. Concurrently, Gene Set Enrichment Analysis (GSEA) was applied, establishing a strong link between elevated levels of ERBB3 isoforms and critical oncogenic pathways, including DNA repair and androgen response. RT-PCR analysis targeting the exon 21-23 and exon 23 regions of ERBB3 confirmed its heightened expression in tumor tissues, underscoring the significance of alternative splicing and exon utilization in cancer development. These findings elucidate the diverse impacts of ERBB3 isoforms on RCC, suggesting their potential as diagnostic markers and therapeutic targets. This study emphasizes the need for further exploration into the specific roles of these isoforms, which could inform more personalized and effective treatment modalities for renal clear cell carcinoma.

Human-Mimic Submuscular and Premuscular Irradiated Rat Model: Histologic Characteristics of the Capsule Tissue in Contact with the Breast Implant.

Background: In this study, we established two rat models that mimic human submuscular and premuscular breast reconstruction. We analyzed the capsule formation according to surgical techniques and adjacent tissues, including the chest wall tissues, such as the ribs and acellular dermal matrices (ADMs) that come in contact with silicone implants. Methods: This study consisted of experiments on 12 Sprague-Dawley rats that underwent implant reconstruction using ADM. They were divided into two groups: rats that underwent dual-plane implantation (n = 6; group 1) and those that underwent premuscular implant insertion (n = 6; group 2). All rats were irradiated with 35 Gy of fractionated radiation. Three months after surgery, the histology and immunochemistry of the capsule tissues of the ADM, muscle, and chest wall were analyzed. Results: Overall capsule thickness was thicker in group 1. Based on the tissue in contact with the silicone implant, ADM had a thinner capsule, less inflammation, less fibrosis, and less vascularization than the muscle and chest wall tissues. Conclusions: This study described two rat models of clinically relevant implant-based breast reconstruction using a submuscular and premuscular plane, ADM, and irradiation. Overall, the premuscular implantation rat model was associated with a thinner capsule. The ADM in contact with the silicone implant, even after irradiation, had superior protection from radiation compared with the other tissues.

A Simplified Algorithmic Approach to Vulvar Reconstruction According to Various Types of Vulvar Defects.

OBJECTIVE: Various surgeons adopt various vulvar reconstruction methods for different types of vulvar defects to restore anatomical structures. Vulvar reconstruction has relatively few references as it is performed in many different ways. Our report aimed to create a simplified reconstruction algorithm that can be used to select the reconstruction flap and to compare clinical outcomes. METHODS: The patients who underwent vulvar reconstruction between April 2017 and May 2020 were retrospectively reviewed. The reconstruction flap was selected according to a suggested algorithm, which accounted for the defect location depending on the vulvo-thigh junctional crease-the visual landmark of the inferior pubic ramus-and proper perforator location. Postoperative surgical complications, functional outcomes, and oncologic outcomes were analyzed according to the histologic and flap types. RESULTS: Forty-seven patients underwent reconstruction with 31 internal pudendal artery perforator flaps (66%) and 16 profunda artery perforator flaps or transverse upper gracilis flaps (34%). The histologic type included 21 extramammary Paget disease (44.7%), 20 squamous cell carcinoma (42.6%), and 6 other types (12.8%). Postoperative complications, including wound and functional complications, occurred in 10 patients (21.3%). There were more cases of wound complications with profunda artery perforator flaps and transverse upper gracilis flaps (37.5%) than those with internal pudendal artery perforator flaps (12.9%) (P = 0.04). There were 7 cases (14.9%) of 2-year oncologic recurrence with no significant differences in terms of histologic or flap types. CONCLUSIONS: According to our suggested simplified algorithm, various types of flaps resulted in reliable surgical outcomes with minimal complication rates and acceptable functional and oncologic outcomes, and the primary goals of vulvar reconstruction were achieved effectively. Using our algorithm, selection of the reconstruction method could be simplified and specified despite the complexity of vulvar defects.

Safety of Augmenting Breast Volume in Direct-to-Implant Breast Reconstruction With Contralateral Breast Augmentation: Comparison With 2-Stage Reconstruction.

BACKGROUND: Direct-to-implant breast reconstruction is a standard method of implant-based reconstruction; however, the risk of skin necrosis and implant failure exists. During simultaneous contralateral augmentation, an implant larger than the resected tissue must be inserted to balance both sides, which may increase the risk of complications. This study examined the differences in the incidence of complications between the single-stage direct-to-implant reconstruction and 2-stage reconstruction when contralateral augmentation was performed simultaneously. METHODS: This study included 99 patients who underwent implant-based breast reconstruction with contralateral augmentation between 2012 and 2020. A retrospective chart review was conducted and the patients were divided into 2 groups: the single-stage reconstruction (n = 61) and 2-stage reconstruction (TSR, n = 38) groups. Demographic data and surgical and oncological information were collected. Complications including skin necrosis and reconstruction failure were investigated as the primary outcome. RESULTS: Implant volume and contralateral implant volume were significantly greater in TSR group than in the single-stage reconstruction group. There were no significant differences in the incidence of complications and reconstruction failure rates between both groups. The nipple-sparing mastectomy was the risk factor for complications. Furthermore, the risk factors for mastectomy skin necrosis were implant volume and differences in the volume of both implants. CONCLUSIONS: Single-stage reconstruction did not increase the risk of complications compared with TSR when implants that were larger than the resected tissue were inserted after mastectomy. Proper patient selection and selection of implants that are not excessively large could satisfy patients' cosmetic needs in a single operation.

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.

Comparative Study of DIEP and PAP Flaps in Breast Reconstruction: Reconstructive Outcomes and Fat Necrosis.

BACKGROUND: This study compared the reconstructive outcomes and fat necrosis of the profunda artery perforator (PAP) flap with those of the deep inferior epigastric perforator (DIEP) flap. METHODS: Data on all DIEP and PAP flap breast reconstructions performed between 2018 and 2021 at Asan Medical Center were compared. The overall reconstructive outcomes and presence of fat necrosis were analyzed through ultrasound evaluation performed by a board-certified radiologist. RESULTS: The PAP (n = 43) and DIEP flaps (n = 99) were used to reconstruct 31 and 99 breasts, respectively. The average age of the patients in the PAP flap group (39.1 ± 7.3 years) was lower than in the DIEP flap group (47.4 ± 7.7 years), and the body mass index (BMI) of patients undergoing PAP flap reconstruction (22.7 ± 2.8 kg/m2) was lower than those undergoing DIEP flap reconstruction (24.3 ± 3.4 kg/m2). There was no total loss of both flaps. Donor site morbidity was higher in the PAP flap group (11.1%) compared with the DIEP flap (1.0%). The rate of fat necrosis was higher in the PAP flaps (40.7%) than in the DIEP flaps (17.8%) during ultrasound. CONCLUSION: In our study, we found that PAP flap reconstruction tended to be performed in patients who were younger with lower BMIs compared with the DIEP flap. Successful reconstructive outcomes were observed in both the PAP and DIEP flaps; however, a higher rate of necrosis was observed in the PAP flap compared with the DIEP flap.

Cadaveric Study for Safe Elevation of a Profunda Artery Perforator Flap: Anatomy of the Perforators and Obturator Nerves.

BACKGROUND: This cadaveric study aimed to describe the anatomy of the profunda artery perforators (PAPs). METHODS: In total, nine free cadavers with 18 upper thighs were dissected, 12 of which were from female cadavers, and 6 were from male cadavers. The average age of the cadavers was 84.7 ± 4.2 years. Dissection was performed to evaluate the anatomic position and characteristics of the femoral PAPs. The perforator distance from the gluteal sulcus, number of perforators, perforating muscles, diameter of the perforators, origin of the perforators, and number of nerves passing above and below the perforators were determined. RESULTS: The average number of perforators that penetrate the adductor magnus muscle was 2.5. The average distance from the origin of the perforators to the gluteal sulcus was 71.72 ± 28.23 mm. The average numbers of the obturator nerves passing above and below the perforator in the adductor magnus muscle were 1.3 (range, 0-4) and 0.7 (range, 0-2), respectively. CONCLUSION: The results provide a detailed anatomic basis for the PAP flap. The perforators of a PAP flap may be included in a flap with a transverse design. Sacrificing the small obturator nerves during dissection may not lead to significant donor site morbidity.

A Propensity Score-matched Analysis of Long-term Oncologic Outcomes After Nipple-sparing Versus Conventional Mastectomy for Locally Advanced Breast Cancer.

OBJECTIVES: To compare the long-term oncologic outcomes of nipple-sparing mastectomy (NSM) with those of conventional mastectomy (CM) in patients with locally advanced breast cancer (LABC) receiving neoadjuvant chemotherapy (NACT). SUMMARY OF BACKGROUND DATA: NSM has been increasingly implemented in patients with breast cancer. However, oncologic efficacy of NSM in patients with LABC has not been sufficiently demonstrated. METHODS: The study group comprised 850 patients with clinical stage IIB to IIIC breast cancer who underwent NACT followed by either NSM and immediate breast reconstruction or CM alone. After propensity score-matching, 418 patients were included in the analysis. Local recurrence-free survival, disease-free survival (DFS), distant metastasis-free survival, and overall survival (OS) rates were calculated using the Kaplan-Meier method and compared using log-rank tests between the NSM and CM groups. RESULTS: After matching, the mean follow-up period was 70 ± 25 months for the NSM group and 74 ± 27 months for the CM group ( P = 0.181). There were no significant differences between the groups in terms of 6-year local recurrence-free survival (91.6% vs. 95.8%; P = 0.239), DFS (70.5% vs. 73.4%; P = 0.583), distant metastasis-free survival (79.8% vs. 77.4%; P = 0.320), or OS (87.6% vs. 84.8%; P = 0.465) rates. Additionally, we identified 30 patients in the NSM group who initially presented with tumor extension in the subareolar area; the nipple-areola complex was successfully preserved after NACT, and no recurrence at the nipple was observed in these patients. CONCLUSIONS: In this matched control study, we demonstrated comparable long-term oncologic outcomes between NSM with immediate reconstruction and CM alone after NACT for LABC. In patients who had tumors extending to the subareolar area before NACT, NSM can be tried if tumor involvement of the nipple-areola complex appears resolved on imaging studies after chemotherapy.

Breast cancer outcomes following immediate breast reconstruction with implants versus autologous flaps: a propensity score-matched study.

PURPOSE: A large proportion of patients with breast cancer who had mastectomy had undergone breast reconstruction with implants or autologous flaps. However, only a few studies have compared the breast cancer outcomes between the implant-based reconstruction (IBR) and autologous flap reconstruction (AFR). In this study, we retrospectively compared the local recurrence rates, distant metastasis rates, and survival outcomes between immediate IBR and AFR. METHODS: A total of 1530 patients with primary breast cancer who underwent IBR or AFR with nipple-/skin-sparing mastectomy were included. Patients who underwent neoadjuvant systemic therapy were excluded from the study. After propensity score matching by age at diagnosis, T stage, N stage, molecular subtype, mastectomy type, adjuvant radiotherapy status, and follow-up period, 938 patients were 1:1 matched, comprising the well-balanced IBR and AFR groups. Locoregional recurrence-free survival (LRRFS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and breast cancer-specific survival (BCSS) were compared between the matched groups. RESULTS: After matching, the median follow-up periods were 68 months and 71 months for the IBR and AFR groups, respectively. No significant differences were observed between the IBR and AFR groups regarding the local recurrence (7.2% vs. 5.1%; P = 0.175), regional recurrence (2.1% vs. 1.5%; P = 0.463), or distant metastasis (3.2% vs. 3.2%; P = 1.000) rates. Moreover, no significant difference was observed between the IBR and AFR groups in the LRRFS (hazard ratio, 0.691; 95% CI, 0.433-1.102; P = 0.118), DFS (hazard ratio, 0.709; 95% CI, 0.468-1.076; P = 0.104), DMFS (hazard ratio, 1.006; 95% CI, 0.491-2.059; P = 0.987), or BCSS (hazard ratio, 0.445; 95% CI, 0.111-1.786; P = 0.659). CONCLUSION: In this propensity score-matched analysis of oncologic outcomes in patients with primary breast cancer who underwent immediate breast reconstruction with nipple-/skin-sparing mastectomy, no significant differences were observed between the IBR and AFR groups.

Outcome Analysis Depending on the Different Types of Incision following Immediate Breast Reconstruction.

Background: Immediate breast reconstruction following nipple-sparing mastectomy (NSM) is widely used for its cosmetic benefits. Due to the lack of guidelines, the types of incisions in NSM vary and which method is superior remains a debate. In this study, we hypothesized that the periareolar incision has a higher risk of complications, such as nipple-areolar complex (NAC) necrosis, than other incisions. Methods: A retrospective chart review was conducted and divided into three groups: the periareolar, radial, and lateral incision groups. The reconstruction method and complications of NAC necrosis, wound dehiscence, seroma, hematoma, infection, and reconstruction failure were investigated. Results: A total of 103 patients (periareolar incision (33%, n = 34), radial incision (39.8%, n = 41), and lateral incision (27.2%, n = 28)) who underwent NSM and immediate breast reconstruction from 2018 to 2020 were included. The reconstruction methods were direct-to-implant, DIEP flap, LD flap, and PAP flap, and there was all of which had no statistically significant difference between the groups regarding the reconstruction method (p=0.257). In terms of complications, there was no significant difference in NAC necrosis (29.4%, 19.5%, and 21.4%, in the periareolar, radial, and lateral groups, respectively; p=0.578), wound dehiscence, seroma or hematoma, infection, and reconstruction failure. Conclusion: Breast reconstruction following NSM through periareolar incision does not increase the incidence of complications, including NAC necrosis. However, since only Asian patients with low BMI were included, if an appropriate patient group is selected for immediate reconstruction after NSM, reconstruction can be safely performed through the periareolar incision, and good cosmetic results can be obtained.

Is There a Difference in the Diagnosis and Prognosis of Local Recurrence between Autologous Tissue and Implant-Based Breast Reconstruction?

Introduction: Breast reconstruction has become common after total mastectomy; however, certain types of breast reconstruction may be associated with delayed local recurrence or poor survival. Here, we investigated whether there are differences in the diagnosis and prognosis of local recurrence between autologous reconstruction and implant reconstruction. Materials and Methods: A retrospective analysis was performed on patients undergoing breast cancer surgery with autologous tissue or immediate implant reconstruction in a single center (January 2003-December 2017). Patient data including the period from cancer surgery to local recurrence diagnosis, tumor size at the time of recurrence, and survival time after cancer surgery and recurrence detection were analyzed. Results: There was a significant difference (p = 0.021) in the time from surgery to recurrence between the autologous tissue (1,246 days) and implant (909 days) groups. Recurrence tumor size did not differ (autologous: 1.00 cm2 vs. implant: 0.90 cm2; p = 0.813). Survival time after surgery (p = 0.63) and recurrence detection (p = 0.74) did not statistically significant. Conclusions: Statistical difference in the detection time was observed between autologous tissue and implant group. On the other hand, there is no difference in recurrence tumor size or survival time. A further study is necessary to identify the different detection time of local recurrence.

Revision Rates of Left and Right Breast Reconstruction Differ With DIEP Flaps: Implications for Inexperienced Surgeons.

BACKGROUND: The internal mammary system provides the recipient vessel of choice in free autologous tissue breast reconstruction. However, left internal mammary veins (IMVs) are smaller than right IMVs, thus raising questions about their reliability. Here we analyzed right and left breast deep inferior epigastric perforator (DIEP) flap reconstruction performed by an experienced versus less experienced surgeon and hypothesized that less experienced surgeons might encounter difficulty in cases of smaller left IMVs. METHODS: We respectively reviewed the charts of 714 DIEP flap breast reconstructions performed by an experienced surgeon (>15 years' DIEP flap experience) and 231 performed by a relatively inexperienced surgeon (<4 years' DIEP flap experience). Reconstructions requiring microvascular revisions were compared with nonrevision controls, and left-side reconstructions were compared with right-side controls. RESULTS: Preoperative risk factors were not significantly different between the left and right cohorts for either surgeon. The experienced surgeon performed 17 microvascular revisions (2.4%), including 9 left (52.9%) and 8 right (47.1%). The less experienced surgeon performed 7 microvascular revisions (3.0%), all left. The left- and right-side revision rates were 2.4% and 2.3% for the experienced surgeon versus 6.1% and 0% for the less experienced surgeon, respectively, with a higher rate for the left side (P = 0.0299). CONCLUSIONS: The left-side microvascular revision rate was higher for the less experienced surgeon. Considering that left IMVs are smaller, less experienced surgeons should carefully perform left-side free flap breast reconstructions and be prepared to convert to thoracodorsal recipient vessel use.

Seasonal and Temperature-associated Effect on Infection in Implant-based Breast Reconstruction.

BACKGROUND AND OBJECTIVES: Despite advances in medicine, infection at the surgical site is an impregnation problem that most surgeons confront. Although studies on the seasonality of infection have been conducted in various areas, no study has confirmed the relationship between seasonal temperature and infection after breast reconstruction. METHODS: From 2008 to 2018, a retrospective study was conducted on patients who underwent implant-based breast reconstruction. Patient demographics, intraoperative data, postoperative data, and temperature information were collected. Temperature differences between cases with and without infection were examined. The differences in the incidence and risk of infection by season were estimated according to the hot season (July to August) and the nonhot season (September to June). RESULTS: Of the 460 cases enrolled, 42 cases developed an infection. Among them, 15 (35.71%) cases developed infection during the hot season (P = 0.003). According to the logistic regression model, the risk of infection was 2.639 times higher in the hot season than in the nonhot season (95% confidence interval, 1.282-5.434; P = 0.008). When the temperature was higher than 25°C, the risk of infection increased by 45.2% for every 1°C increase, which was statistically significant (odds ratio, 1.452; 95% confidence interval, 1.198-1.76; P < 0.001). CONCLUSION: In conclusion, the hot season or average temperatures higher than 25°C increase the risk of infection in patients undergoing implant-based breast reconstruction. It is essential to focus on skin hygiene during the healing of the incision site.

The PAP Flap Breast Reconstruction: A Practical Option for Slim Patients.

BACKGROUND: The posterior thigh-based profunda artery perforator (PAP) flap has been an emerging option as a secondary choice in breast reconstructions. However, whether a PAP flap could consistently serve as the secondary option in slim patients has not been investigated. METHODS: Records of immediate unilateral breast reconstructions performed from May 2017 to June 2019 were reviewed. PAP flap breast reconstructions were compared with standard deep inferior epigastric perforator (DIEP) flap breast reconstructions, and were grouped into single or stacked PAP flaps for further analysis. RESULTS: Overall, 43 PAP flaps were performed to reconstruct 32 breasts. Eleven patients underwent stacked PAP flap reconstruction, while 17 patients underwent 21 single PAP flap reconstruction. The average body mass index (BMI) of the patients was 22.2 ± 0.5 kg/m2. The results were as follows: no total loss, one case of venous congestion (2.3%), two donor site wound dehiscence cases (4.7%), and one case of fat necrosis from partial flap loss (2.3%). When compared with 192 DIEP flap reconstructions, the final DIEP flap supplied 98.1 ± 1.7% of mastectomy weight, while the final PAP flap supplied 114.1 ± 6.2% of mastectomy weight (p < 0.005), demonstrating that PAP flaps can successfully supply final reconstruction volume. In a separate analysis, single PAP flaps successfully supplied 104.2% (84.2-144.4%) of mastectomy weights, while stacked PAP flaps supplied 103.7% (98.8-115.2%) of mastectomy weights. CONCLUSION: In our series of PAP flap reconstructions performed in low-to-normal BMI patients, we found that PAP flaps, as single or stacked flaps, provide sufficient volume to reconstruct mastectomy defects.

The Influence of Flow Velocity in the Feeding Vessel on Flap Perfusion in Deep Inferior Epigastric Artery Perforator Flap.

BACKGROUND: Contralateral perfusion of zones II and IV is critical to estimate the amount of fat necrosis and determine intraoperative flap sacrifice during autologous breast reconstruction. We aimed to determine whether perfusion of the contralateral side was affected by the peak flow velocity in the feeding vessels in the deep inferior epigastric artery (DIEA) perforator free flap reconstructions. METHODS: This was a retrospective review of patients who received DIEA perforator flap for autologous breast reconstruction from February to July 2020. Intraoperative indocyanine green (ICG) angiography and measurement software (Image J) were used to validate the perfusion of the contralateral side of the flap. Peak flow in the vessels was measured with duplex color Doppler and linear correlation was used to analyze the association between perfusion and blood flow velocity. RESULTS: Forty-two patients received a DIEP flap. The average age of the patients was 48.5 years, and body mass index was 23.84 kg/m2. Peak flow velocity of the internal mammary artery (IMA) was significantly higher than that of the DIEA (p <0.05). Contralateral perfusion confirmed by ICG angiography was higher in the IMA than in the DIEA (p <0.05). A linear correlation was found between peak speed (p = 0.045) and ICG perfusion length (p = 0.00003). CONCLUSION: The status of flap perfusion depends on the feeding vessel. The velocity of blood flow between IMA and DIEA is different, and the flap perfusion varies accordingly. Therefore, ICG angiography should be performed after anastomosis at the recipient site for an accurate assessment.

Intramuscular Deep Inferior Epigastric Vessels Are Insulated by Perimysial Fibroadipose Tissue Network.

BACKGROUND: The difficulty of elevating a deep inferior epigastric perforator (DIEP) flap largely depends on the intramuscular course of the vessel and the perforator. Previous studies, however, have lacked histologic descriptions of the vessels and surrounding structures. The present study analyzed the histologic aspects of the deep inferior epigastric vessels and perforators, focusing on their perivascular relationships with muscle fibers. METHODS: The abdomen of a cadaver was histologically evaluated to identify intramuscular deep inferior epigastric vessels. Tissue samples were stained with hematoxylin and eosin and with Masson trichrome stain to visualize fibrous components. Twenty-one DIEPs from 12 patients were also evaluated to determine the histologic aspects of the perivascular structure. In the cross-section of each perforator and adjacent tissue, the perforator-to-muscle distance and trichrome-stained area were measured, and the correlation of the perforator size with the perforator-to-muscle distance and the percent collagenous portion of the distance were determined. RESULTS: Histologic analysis showed that the deep inferior epigastric vessels and perforators were encased by perimysial connective tissue and were not in direct contact with the muscle fibers. The smaller perimysia branched out from the larger perimysia, forming an interconnecting network structure. Correlation analysis showed that larger vessels had more collagenous portions in the perimysial structures (Spearman's ρ = 0.537, p = 0.012). CONCLUSION: The deep inferior epigastric vessels and perforators reside in a perimysial fibroadipose tissue network. This may provide surgeons with a microscopic perspective during DIEP dissections. Having an idea of the perforator anatomy in microscopic level can help us to perform safer perforator dissections.

A propensity score-matched comparison of recurrence outcomes after immediate implant vs autologous flap reconstruction in patients receiving neoadjuvant chemotherapy for breast cancer.

PURPOSE: We compared oncologic outcomes between breast cancer patients who underwent immediate implant-based breast reconstruction (IBBR) and those who underwent autologous flap reconstruction (AFR) after neoadjuvant chemotherapy (NACT). METHODS: The study group comprised 536 patients with primary breast cancer who underwent NACT followed by immediate IBBR or AFR. After propensity score matching, 138 patients in the IBBR group and 276 patients in the AFR group were selected for comparisons of locoregional recurrence-free survival (LRRFS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and breast cancer-specific survival (BCSS). RESULTS: No significant differences were observed between the matched groups in locoregional recurrence rates (IBBR vs. AFR: 12.3% vs. 12%; P = 0.915) and distant metastasis (13% vs. 17%; P = 0.293). There was also no significant difference between the groups in LRRFS (P = 0.956), DFS (P = 0.606), DMFS (P = 0.283), or BCSS (P = 0.121). The 5- and 10-year LRRFS rates were 87.6% and 85.9% in the IBBR group, and 87.7% and 86.1% in the AFR group; the 5- and 10-year DFS rates were 79% and 77.5% in the IBBR group, and 77% and 75% in the AFR group; the 5- and 10-year DMFS rates were 85.9% and 85.9% in the IBBR group, and 83.2% and 81.8% in the AFR group; and the 5- and 10-year BCSS rates were 97.8% and 91.3% in the IBBR group, and 91.8% and 86% in the AFR group, respectively. CONCLUSIONS: In this propensity score-matched analysis of oncologic outcomes in breast cancer patients who underwent immediate reconstruction after NACT, no significant differences were observed between the IBBR and AFR groups.