Jai-Kyong Pyon’s research while affiliated with Samsung Medical Center and other places

In the realm of implant-based breast reconstruction, mastectomy flap necrosis (MFN) is a prevalent yet grave complication that poses a threat to the stability of the inserted prosthesis. Although numerous investigations have scrutinized the risk factors for MFN development, few have delved into the aftermath, specifically implant failure or salvage. This study seeks to appraise the prognosis of the implanted prosthesis following MFN occurrence, as well as identify predictors of such outcomes. Among patients who underwent immediate implant-based reconstruction between 2010 and 2022, individuals with MFN development were identified and scrutinized regarding the fate of their prosthesis (salvaged/failed). Independent risk factors were identified using multivariable analyses and subgroup analyses accounting for diverse clinical settings. Among a total of 3128 cases, 422 of MFN (194 partial, 228 full-thickness necrosis) were examined. Of them, 384 prostheses (91%) were salvaged, while 38 (9%) failed. Multivariate analysis revealed predictors of reconstruction failure included nipple-sparing mastectomy, larger skin excision, type of acellular dermal matrix used, previous radiotherapy, and full-thickness necrosis, while operation procedures, including type of operation and plane for prosthesis insertion (prepectoral/subpectoral), showed no significant associations. Risk factors differed by insertion plane, with obesity, larger skin excision, and previous radiation history significant in the prepectoral group, and only MFN degree influencing successful salvage in the subpectoral. This study sheds light on the importance of understanding the prognosis and potential predictors of implant failure/salvage following MFN, emphasizing the need for tailored approaches to minimize the risk of reconstruction failure. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266.

Purpose: Neoadjuvant chemotherapy (NACT) followed by total mastectomy and immediate reconstruction has become an important strategy in the treatment of breast cancer. Although the safety of subpectoral implant-based breast reconstruction with NACT has been extensively evaluated, the safety in prepectoral reconstruction has not been clearly elucidated. We aimed to evaluate the association of NACT with immediate prepectoral breast reconstruction outcomes. Methods: A retrospective review of patients who underwent total mastectomy and immediate implant-based prepectoral breast reconstruction between May and December 2021 was conducted. Patients were categorized into 2 groups: those receiving NACT and those not receiving it. Postoperative complication rates were compared between the 2 groups. The independent association between NACT and the complication profiles was evaluated. Propensity score matching was also conducted. Results: We analyzed 343 cases, including 85 who received NACT treatment and 258 who did not. Compared with the non-NACT group, the NACT group was younger, had a higher body mass index, and a higher rate of adjuvant radiotherapy. There were no differences in the rates of overall complications or type of complication between the 2 groups. In the multivariable logistic analyses, NACT did not show a significant association with the development of adverse outcomes. Similar results were observed in propensity score matching analyses. Conclusions: Our results suggest that receiving NACT may not have a significant detrimental effect on the postoperative outcomes of immediate prepectoral prosthetic reconstructions. Conducting prepectoral implant-based reconstruction in the setting of NACT might be safe and provide acceptable outcomes.

Background: Reconstruction of penoscrotal defects resulted from margin-controlled excision of extramammary Paget's disease (EMPD) remains challenging, due to its unpredictably varying extents. The present study aimed to investigate outcomes of reconstruction of penoscrotal defects following radical excision of EMPD and to introduce a simplified algorithm for selecting reconstruction strategies. Methods: Patients with penoscrotal EMPD who were treated with wide excision and subsequent reconstruction from 2009 to 2020 were reviewed. Their demographics, operation-related characteristics, and postoperative outcomes were evaluated. Results: In total, 46 patients with a mean age of 64.9 years (range, 44-85 years) were analyzed. An average size of defects was 129.6 cm2 (range, 8-900 cm2 ). The most frequently involving anatomical subunit was scrotum, followed by suprapubic area and penile shaft. Twenty-six patients had defects spanning multiple subunits. The most commonly used reconstruction methods for each anatomical subunit were internal pudendal artery perforator (IPAP) flaps and/or scrotal flaps for scrotal defects, superficial external pudendal artery perforator (SEPAP) flaps for suprapubic defects, and skin grafts for penile defects. In all but four cases, successful reconstruction was achieved with combination of those reconstruction options. No major complications developed except for one case of marginal flap necrosis. All patients were satisfied with their aesthetic and functional results. Conclusions: Diverse penoscrotal defects following excision of EMPD could be solidly reconstructed with combination of several loco-regional options. A simplified algorithm using in combination of IPAP flap, SEPAP flap, scrotal flap, and skin graft may enable efficient and reliable reconstruction of penoscrotal EMPD defects.

Aim Both skin-sparing mastectomy (SSM) and nipple-sparing mastectomy (NSM) have been widely adopted. Although postmastectomy radiation therapy (PMRT) can improve clinical outcomes, it can worsen cosmesis following reconstruction. Therefore, identifying risk factors of ipsilateral breast tumor recurrence (IBTR) could help de-escalate PMRT after NSM/SSM in patients with pT1-2 disease. Methods We retrospectively reviewed patients treated with SSM (N = 400) and NSM (N = 156) in patients with pT1-2N0-1 disease between 2009 and 2016. Seventy-four patients received PMRT with 50–50.4 Gy in 25–28 fractions. The Cox proportional hazards model was used to analyze the prognostic factors of IBTR. Results With a median follow-up of 66.2 months, 17 IBTR events were observed, with 5-year IBTR-free rate of 97.2%. Although only one IBTR was observed after PMRT, there was no statistical difference in the 5-year IBTR-free rate (PMRT vs. no PMRT, 98.6% vs. 97.0%, p = 0.360). Multivariable analyses demonstrated that age ≤45 years and lymphovascular invasion (LVI) were adverse features of IBTR. The low-risk group (0 risk factor) showed a better 5-year IBTR-free rate than the high-risk group (≥1 risk factor) (100.0% vs. 95.8%, p = 0.003). In the high-risk group, PMRT slightly improved 5-year IBTR-free rate compared with no PMRT (98.6% vs. 95.2%, p = 0.166). In addition, PMRT increased 5-year cumulative incidence of reconstruction failure (10.0% vs. 2.8%, p = 0.001). Conclusion We identified risk factors (age and LVI) related to IBTR following upfront SSM/NSM with pT1-2 disease. As a hypothesis-generating study, de-escalation of PMRT by omitting chest wall irradiation in selective patients could improve reconstruction-related complications without compromising oncologic outcomes.

Background: The latissimus dorsi (LD) muscle originates from the lower thoracic spine with broad attachment and plays a subsidiary role in spinal postural stability. We investigated whether harvesting unilateral LD muscle for breast reconstruction could influence spinal posture in the long-term. Methods: Patients who underwent immediate unilateral breast reconstruction between 2002 and 2010 were reviewed. They were grouped according to reconstruction methods: LD muscle flap and tissue expander/implant. The Cobb angle was assessed twice at each of five different time points (preoperative/postoperative 2, 4, 6, and 8 years) by an independent physician blinded to the reconstruction modality. Postoperative scoliosis was defined as a mean Cobb angle >10° at 8 years postoperatively. The trends of changes in Cobb angle over time and the rate of postoperative scoliosis were compared between reconstruction methods. Results: In total, 153 women were analyzed, including 102 using LD muscle flap and 51 using tissue expander/implant, with a median follow-up of 103.0 months. The LD flap group showed enhanced trends of increasing postoperative Cobb angles as compared with the tissue expander/implant group, and the difference remained significant after adjusting for other variables (p = 0.001). The rate of postoperative scoliosis was significantly higher in the LD flap group than in the control group (p = 0.029). Multivariable analyses revealed that use of the LD flap was associated with a significantly increased rate of postoperative scoliosis. Conclusions: Unilateral LD muscle flap harvest for breast reconstruction might be associated with changes of spinal posture in the long run.

Background: Time intervals for expander-to-implant exchange from radiation therapy have been reported to reduce device failure. This study investigated the optimal timing of expander-to-implant exchange after irradiation in terms of short- and long-term outcomes. Methods: This retrospective review enrolled consecutive patients who underwent immediate two-stage breast reconstruction and radiation therapy to tissue expanders from 2010 to 2019. Receiver operating characteristic curves and the Youden index were used to estimate the optimal time from radiation therapy to implant placement in terms of 49-day (early) and 2-year (late) complications. Logistic regression analysis was performed to identify the risk factors for each complication. Results: Of the 1675 patients, 133 were included. The 49-day and 2-year complication rates were 8.3 percent and 29.7 percent, respectively. Capsular contracture was the most common 2-year complication. The Youden index indicated that implant placement at 131 days after radiation therapy was most effective in reducing the 49-day complications, but that the 2-year complication was less significant, with lower sensitivity and area under the curve. Modified radical mastectomy, expander fill volume at radiation therapy, and size of permanent implant increased the odds of 49-day complications; none of them was associated with the odds of 2-year complications. Conclusions: To reduce short-term complications, the best time point for permanent implant placement was 131 days after radiation therapy. However, there was no significant time interval for reducing long-term complications. Capsular contracture was an irreversible complication of radiation injury that was not modified by postirradiation variables including the time from irradiation or size of permanent implant. Clinical question/level of evidence: Therapeutic, III.

Background: Despite the long-standing presumption that nighttime surgery could affect adverse outcomes, its association independent of patient's general condition and disease severity remains unclear. We hypothesized that conducting elective surgery for subjects with good physical status at nighttime was not associated with increased risks of postoperative complications and aimed to examine it in tissue-expander-insertion (TEI) operation for breast reconstruction. Method: Patients who underwent immediate unilateral TEI-based breast reconstruction between 2014 and 2019 were enrolled. They were categorized into 3 groups based on the starting time of the TEI operation: 8 AM to 6 PM (group 1), 6 PM to 8 PM (group 2), and after 8 PM (group 3). The postoperative complication rates were compared among the groups. The independent associations of each variable, including the operation starting time and adverse outcomes, were analyzed. Results: In total, 1458 patients were analyzed, including 970 in group 1, 358 in group 2, and 130 in group 3. The groups showed similar baseline characteristics regarding comorbidities and the American Society of Anesthesiologists classification. Compared with group 1, group 3 was associated with significantly increased rates of overall complications including infection, reoperation, and premature removal of the tissue expander. These differences retained influences in the multivariable analyses. Group 3 showed a significantly longer hospitalization period than the other 2 groups. The complication rates did not differ between groups 1 and 2. Conclusions: Conducting TEI operation at nighttime seems to be associated with increased risks of adverse postoperative outcomes compared with conducting it during regular working hours.

Background: Since April 2015, the Korean National Health Insurance (NHI) has reimbursed breast cancer patients, approximately 50% of the cost of the breast reconstruction (BR) procedure. We aimed to investigate NHI reimbursement policy influence on the rate of immediate BR (IBR) following total mastectomy (TM). Methods: We retrospectively analyzed breast cancer data between April 2011 and June 2016. We divided patients who underwent IBR following TM for primary breast cancer into "uninsured" and "insured" groups using their NHI statuses at the time of surgery. Univariate analyses determined the insurance influence on the decision to undergo IBR. Results: Of 2,897 breast cancer patients, fewer uninsured patients (n = 625) underwent IBR compared with those insured (n = 325) (30.0% vs. 39.8%, P < 0.001). Uninsured patients were younger than those insured (median age [range], 43 [38-48] vs. 45 [40-50] years; P < 0.001). Pathologic breast cancer stage did not differ between the groups (P = 0.383). More insured patients underwent neoadjuvant chemotherapy (P = 0.011), adjuvant radiotherapy (P < 0.001), and IBR with tissue expander insertion (P = 0.005) compared with those uninsured. Conclusion: IBR rate in patients undergoing TM increased after NHI reimbursement.