Detection of Fibril Nucleation in Micrometer-Sized Protein Condensates and Suppression of Sup35NM Fibril Nucleation by Liquid-Liquid Phase Separation.

Elucidating the link between amyloid fibril formation and liquid-liquid phase separation (LLPS) is crucial in understanding the pathologies of various intractable human diseases. However, the effect of condensed protein droplets generated by LLPS on nucleation (the initial step of amyloid formation) remains unclear because of the lack of available quantitative analysis techniques. This study aimed to develop a measurement method for the amyloid droplet nucleation rate based on image analysis. We developed a method to fix micrometer-sized droplets in gel for long-term observation of protein droplets with known droplet volumes. By combining this method with image analysis, we determined the nucleation dynamics in droplets of a prion disease model protein, Sup35NM, at the single-event level. We found that the nucleation was unexpectedly suppressed by LLPS above the critical concentration (C*) and enhanced below C*. We also revealed that the lag time in the Thioflavin T assay, a semi-quantitative parameter of amyloid nucleation rate, does not necessarily reflect nucleation tendencies in droplets. Our results suggest that LLPS can suppress amyloid nucleation, contrary to the conventional hypothesis that LLPS enhances it. We believe that the proposed quantitative analytical method will provide insights into the role of LLPS from a pathological perspective.

The significance of biopsy scar excision at the time of skin- or nipple-sparing mastectomy with immediate breast reconstruction.

BACKGROUND: Neoplastic seeding (NS) can occur after tissue biopsy, which is a clinical issue especially in mastectomy with immediate reconstruction. This is because postoperative radiation is not usually given and local recurrence of preserved skin flap may increase. The purpose of this study is to investigate the importance of preoperative evaluation of NS and the validity of biopsy scar excision. PATIENTS AND METHODS: We retrospectively analysed 174 cases of mastectomy with immediate breast reconstruction. The primary endpoint is the frequency of clinical and pathological NS and the secondary endpoint is the problem of excision of needle biopsy site. RESULTS: Three cases (1.7%) had preoperative clinical findings of NS. Pathological examination revealed NS in all three cases. Biopsy scars could be excised in 115 cases among 171 cases without clinical NS. Pathological NS was found in 1 of 66 (1.5%) cases of which pathological examination was performed. Biopsy scars could not be excised in the remaining 56 cases: the biopsy scar could not be identified in 41 cases, and there was concern about a decrease in flap blood flow after excision in 15 cases. In 12 of these 15 cases, the scars were close to the skin incision; excision of these scars might have triggered skin necrosis between the incision and the biopsy scar excision site. No postoperative complications were observed. CONCLUSIONS: It is important to preoperatively evaluate clinical NS, and biopsy scars should be excised in clinical NS cases. Even in cases without clinical NS, biopsy scar excision should be considered. It is also important to perform a biopsy in consideration of the incision design for reconstructive surgery.

Cosmetic Comparison Between the Modified Uchida Method and the Mustarde Method for Blepharophimosis-Ptosis-Epicanthus Inversus Syndrome.

PURPOSE: Blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) is a rare, congenital, surgically challenging disease. We undertook an objective, functional, and cosmetic comparison between the modified Uchida procedure and the Mustarde procedure on Asian patients with BPES. DESIGN: This is a retrospective, comparative, interventional case series with the description of 2 surgical techniques. PARTICIPANTS: Twenty consecutive Japanese patients with BPES were studied. METHODS: The patients were assigned to either the modified Uchida or the Mustarde procedure on the basis of preoperative intercanthal distance (ICD) ratio (ICD/palpebral fissure width). Intercanthal distance and margin reflex distance were measured from photographs before and after surgery. Classifications were made according to epicanthal fold score and cosmetic score using a visual analog scale (VAS). MAIN OUTCOME MEASURES: The main outcome measures were postoperative improvement in ICD ratio and the VAS. RESULTS: Of the 20 patients, 5 underwent the modified Uchida procedure and the other 15 underwent the Mustarde procedure. The preoperative median ICD ratio was 2.0 (range, 1.9-2.5) and 2.5 (range, 2.0-3.4) for the modified Uchida and Mustarde procedures, respectively, and decreased to 1.5 (range, 1.5-1.7) and 1.6 (range, 1.5-1.8) postoperatively. The mean ICD reduction rate was 35.7% (SD, 1.0%) in the Mustarde group and 22.1% (SD, 1.3%) in the modified Uchida group (P < 0.001).The mean VAS for the modified Uchida and Mustarde procedures was 5.9 (SD, 1.3) and 2.8 (SD, 1.1), respectively, which was statistically significant (P = 0.0166). CONCLUSIONS: Both the modified Uchida and Mustarde procedures could effectively shorten the ICD; however, cosmetic results were significantly superior using the modified Uchida method.

LC3B is indispensable for selective autophagy of p62 but not basal autophagy.

Autophagy is a unique intracellular protein degradation system accompanied by autophagosome formation. Besides its important role through bulk degradation in supplying nutrients, this system has an ability to degrade certain proteins, organelles, and invading bacteria selectively to maintain cellular homeostasis. In yeasts, Atg8p plays key roles in both autophagosome formation and selective autophagy based on its membrane fusion property and interaction with autophagy adaptors/specific substrates. In contrast to the single Atg8p in yeast, mammals have 6 homologs of Atg8p comprising LC3 and GABARAP families. However, it is not clear these two families have different or similar functions. The aim of this study was to determine the separate roles of LC3 and GABARAP families in basal/constitutive and/or selective autophagy. While the combined knockdown of LC3 and GABARAP families caused a defect in long-lived protein degradation through lysosomes, knockdown of each had no effect on the degradation. Meanwhile, knockdown of LC3B but not GABARAPs resulted in significant accumulation of p62/Sqstm1, one of the selective substrate for autophagy. Our results suggest that while mammalian Atg8 homologs are functionally redundant with regard to autophagosome formation, selective autophagy is regulated by specific Atg8 homologs.

[The anti-inflammatory effect of 0.1% bromfenac and 0.1% betamethasone combination in post-cataract surgery patients with diabetes mellitus].

PURPOSE: To compare the post cataract surgery anti-inflammatory effect of bromfenac monotherapy and of bromfenac and betamethasone combination therapy in diabetes mellitus patients. METHODS: A prospective study approved by the Institutional Review Board. Fifty-one eyes of 51 patients were randomly allocated to either bromfenac 0.1% monotherapy (n = 23) or combined therapy with bromfenac 0.1% and betamethasone 0.1% (n = 28). After surgery, monotherapy group was administered bromfenac alone for 8 weeks, while the combined therapy group was administered both bromfenac and betamethasone for 2 weeks, bromfenac alone for the next 6 weeks. The amount of change from preoperative values in anterior chamber flare and foveal thickness were compared between the 2 groups. RESULTS: There was no significant difference in change in anterior chamber flare between the 2 groups. The increase in foveal thickness 4 weeks postoperatively was significantly larger in the bromfenac group (p = 0.0356). Four patients of the bromfenac group, all with a history of diabetic macular edema, developed macular edema after surgery. CONCLUSION: Bromfenac and betamethasone combination exhibited a stronger anti-inflammatory effect after cataract surgery patients with diabetes mellitus. In particular, patients with a history of diabetic macular edema were susceptible to foveal thickening and macular edema, and a combined treatment is desirable.

Reconstruction of the Infraorbital Nerve Using Bilayered Artificial Nerve Conduits after Partial Maxillectomy.

Background: Facial sensory nerves play vital roles in daily functions like self-protection, facial expressions, speaking, and eating. Severing the infraorbital nerve (ION) during partial maxillectomy via the Weber-Ferguson incision can lead to sensory disturbances. This study presents immediate ION reconstruction using artificial nerve conduits and its short-term outcomes. Methods: This retrospective study included three patients (mean age: 67.0 years) undergoing immediate ION reconstruction after partial maxillectomy via the Weber-Ferguson incision. Sensory recovery was evaluated using the Semmes-Weinstein and two-point discrimination (2PD) tests. A reference group of five patients who underwent total maxillectomy without ION reconstruction was also assessed. Results: No postoperative complications were observed during the 15.3-month follow-up. Sensory recovery varied among patients, with one achieving normal perception at 24 months, another showing diminished light touch at 13 months, and the third experiencing diminished protective sensation at 7 months postoperatively. In comparison, the reference group showed lower sensory recovery. Two patients showed improvements in 2PD test results at 24 and 13 months, whereas one showed no recovery at 7 months. No patients in the reference group showed improvement. Conclusion: Immediate ION reconstruction using artificial nerve conduits after partial maxillectomy appears feasible, as evidenced by acceptable sensory recovery in the short term.

Preoperative and postoperative orbital volume in patients with Crouzon and Apert syndrome.

Crouzon and Apert syndromes are frequently complicated by ocular abnormalities and patients with these syndromes often present with abnormal ocular morphology. The present study assesses orbital volume and ocular complications in patients associated with Crouzon and Apert syndromes.During an 8-year period starting in 2002, fronto-orbital advancement was used for cranial expansion on 23 cases of syndromic craniosynostosis. Of those, it was possible to evaluate 5 Crouzon and eight Apert syndrome cases. Orbital volume was measured using multislice CT scans. Both preoperative and postoperative orbital volumes were compared with normal orbital volume.Preoperative orbital volume was 5.8 to 10.0 cm (mean, 7.1 cm) in patients with Crouzon syndrome and 7.2 to 10.8 cm (mean, 9.1 cm) in patients with Apert syndrome. Postoperative intraorbital volume was 9.4 to 11.2 cm (mean, 10.4 cm) in patients with Crouzon syndrome and 11.6 to 13.2 cm (mean, 12.4 cm) in patients with Apert syndrome. The mean of orbital volume relative to the normal volume was 58% preoperatively and 74% postoperatively in patients with Crouzon syndrome and 69% (56-81%) preoperatively and 88% (81-95%) postoperatively in patients with Apert syndrome.In conclusion, orbital volume was smaller in the Crouzon syndrome group than in the Apert syndrome group, and symptoms, such as exophthalmos and exotropia, were noted in the Crouzon syndrome group. Orbit expansion did not fully restore normal orbital volume, but in most cases, it was useful for alleviation of preoperative symptoms (exophthalmos/eyeball prolapse, corneal erosion, conjunctivitis).

Comparison of primary school teachers' stress responses between pre-pandemic and pandemic periods: a large-scale nationwide survey in Japan.

A schoolteacher's job is considered one of the most stressful occupations globally. The coronavirus disease 2019 pandemic has posed further challenges for schoolteachers. This study aimed to examine the effects of the pandemic on primary school teachers' stress responses in Japan. We analyzed the data from a nationwide survey of public-school teachers conducted between June 2019 and December 2021. The total numbers of participants were 65,968 in 2019, 72,248 in 2020, and 75,435 in 2021. Working hours and perceived main stressors as well as stress response scores were assessed. Contrary to expectations, the results showed that the stress response scores among primary school teachers did not increase in the first year of the pandemic. Rather, the stress response scores and the proportion of high-stress teachers significantly decreased from the pre-pandemic year (2019) to the first year of the pandemic (2020). However, the stress response scores showed a rising trend in the second year of the pandemic (2021). Participants' working hours decreased from 2019 to 2021. The findings in relation to teachers' main stressors matched these trends. Continuous monitoring of teachers' stress levels is required both during and after the pandemic.

Hypothyroidism After Using Superior Thyroid Artery as A Recipient Artery.

OBJECTIVE: Superior thyroid artery (SThA) is a common recipient artery in free tissue transfer even after total pharyngolaryngoesophagectomy (TPLE) with hemithyroidectomy. The aim of this study was to evaluate whether the use of SThA as a recipient vessel affect thyroid function in patients undergoing TPLE with hemithyroidectomy. METHODS: From 2011 to 2020, 91 patients who underwent free jejunum transfer after TPLE with hemithyroidectomy were divided into two groups. In Group1 (n = 47), the contralateral SThA was used for the anastomosis. In Group2 (n = 44), other vessels were used. Retrospective chart review was performed comparing postoperative thyroid function between two groups. RESULTS: In group1, 17 patients presented hypothyroidism, 21 presented latent hypothyroidism and 9 presented no thyroid dysfunction comparing 15, 19, and 10 respectively in group 2. There were no significant differences between the two groups. CONCLUSION: Even after hemithyroidectomy, with inferior thyroid arteries are preserved, the SThA can be used as a recipient vessel. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:557-561, 2023.

Effect of Incision Negative Pressure Wound Therapy on Donor Site Morbidity in Breast Reconstruction with Deep Inferior Epigastric Artery Perforator Flap.

Background: The usefulness of closed incision negative pressure wound therapy (ciNPWT) has been well documented in many surgical sites, except for the donor site of the deep inferior epigastric artery perforator (DIEP) flap. The aim of this study was to evaluate the effect of ciNPWT on microsurgical breast reconstruction using a DIEP flap. Methods: Fifty-six cases of breast reconstruction with DIEP flap were included and divided into two groups based on post-surgical wound management: the ciNPWT group received ciNPWT at the donor site, while the conventional group received conventional wound management. The primary outcomes were the incidence of seroma, wound dehiscence, and surgical site infection, and secondary outcomes were the time to drain removal and amount of drainage. The breast reconstruction risk assessment (BRA) score was used to evaluate the comprehensive risk in each case. Results: Among the patient and surgical characteristics, only the BRA score (P=0.02) and the time to elevate the flap (P=0.02) were significantly higher and longer in the ciNPWT group, respectively. The incidence of seroma, dehiscence, and wound infection showed no significant difference between the two groups. In the subgroup analysis of patients with body mass index ≥ 25, the primary outcomes did not differ, while the secondary outcomes were significantly lower in the ciNPWT group (drainage volume, P = 0.04; time to drain removal, P = 0.04). Conclusion: ciNPWT can potentially reduce the incidence of donor site complications of DIEP flaps, especially if the comprehensive risk for post-surgical complications is considered.

Association between working overtime and psychological stress reactions in elementary and junior high school teachers in Japan: a large-scale cross-sectional study.

This study aimed to investigate the relationship between working overtime and psychological stress reactions among school teachers. It also evaluated the interaction of overtime work types (on weekdays, on holidays, and bringing work home) and task content (educational, peripheral and both). This cross-sectional study was conducted on Japanese elementary and junior high school teachers. Primary outcome was psychological stress reactions measured with the Brief Job Stress Questionnaire. Participants were asked how long they work overtime on weekdays, holidays, and at home. Participants were also asked whether they engaged in educational tasks and/or peripheral tasks during that overtime work. Multiple linear regression analyses were applied and 6,135 participants were included in the analyses after imputing missing data. Working hours of all three types were significantly correlated with higher psychological stress reactions. Moreover, engaging in both educational and peripheral tasks showed higher psychological stress reactions than in only educational tasks when working overtime on weekdays and holidays. In conclusion, reducing overtime work regardless of work types is crucial for mitigating psychological stress reactions for teachers. It might also be possible to manage the psychological stress reactions by splitting the role of task contents, when working overtime on weekdays and holidays at school.

Sentinel lymph node biopsy in conjunctival malignant melanoma at the lacrimal caruncle: a case report.

BACKGROUND: Conjunctival malignant melanoma (CMM) is so rare that there are no certain guidelines for its treatment. Factors influencing its prognosis include region of onset, tumor thickness, lymph node metastasis, and distant metastasis. Whether regional lymph node metastasis is present or not is one of the most powerful factors for predicting recurrence in and survival of patients with CMM. METHODS: A 72-year-old man with conjunctival malignant melanoma at the lacrimal caruncle was underwent sentinel lymph node (SLN) biopsy by preoperative lymphoscintigraphy and intraoperative vital blue mapping. RESULTS: A blue-dyed node could be identified in the superficial lobe of the parotid gland. A split half of the cropped SLN was immediately submitted to rapid pathological examination. After confirming no metastasis, it was decided not to perform lymph node dissection. The final diagnosis was pT3N0M0. Neither recurrence nor distant metastasis has been observed for 7 years after the operation. CONCLUSIONS: We were able to evaluate N (lymph node metastasis) in the TNM classification accurately. SLN may facilitate N classification and decisions regarding employment of appropriate lymph node dissection as well as combined therapy after operation.

Karyotype changes in cultured human corneal endothelial cells.

PURPOSE: To examine karyotype changes in cultured human corneal endothelial cells (HCECs). METHODS: HCECs with Descemet's membrane were removed from 20 donors of various ages (range, 2-77 years; average, 43.7+/-26.4 years) and cultured on dishes coated with extracellular matrix produced by bovine corneal endothelial cells (BCECs). Karyotype changes were examined by G-band karyotyping of HCECs at the third passage from 12 donors and the fifth passage from 16 donors. The number of chromosomes was analyzed in 40-50 cells from the third and fifth passages of each HCEC preparation. A detailed karyotype analysis of 10-16 cells from the third and fifth passages of each HCEC preparation was performed. The frequency of aneuploid cells per case (the number of abnormal cells divided by the total number of cells examined at metaphase) was tested for correlation with age by Spearman's correlation analysis. RESULTS: At the third passage, five cases (41.7%) showed an almost normal karyotype, and five cases (41.7%) showed sex chromosome loss. One case (8.3%) showed chromosome 21 trisomy. At the fifth passage, five cases (31.3%) showed an almost normal karyotype, and four cases (25%) showed sex chromosome loss. Three cases (18.8%) showed chromosome 8 trisomy, and one case (6.3%) showed chromosome 21 trisomy. Donor age and the frequency of aneuploidy had a statistically significant correlation at the fifth passage (R=0.653, p=0.042). CONCLUSIONS: Donor age and the frequency of aneuploidy have a positive correlation in cultured HCECs at the fifth passage. Therefore, HCECs for clinical therapies should be obtained from donors as young as possible. Karyotyping cultured HCECs is crucial before clinical application.

Interaction of dynamin I with NAP-22, a neuronal protein enriched in the presynaptic region.

Neurons have well-developed membrane microdomains called "rafts" that are recovered as a detergent-resistant low-density membrane microdomain fraction (DRM). NAP-22 is one of the major protein components of neuronal DRM and localizes in the presynaptic region. In order to know the role of NAP-22 in the synaptic transmission, NAP-22 binding proteins in the cytosol were searched with an affinity screening with NAP-22 as a bait and several protein bands were detected. Using mass-analysis and western blotting, one of the main band of ∼90 kDa was identified as dynamin I. The GTPase activity of dynamin I was partly inhibited by NAP-22 expressed in bacteria and this inhibition was recovered by the addition of calmodulin, a NAP-22 binding protein. The GTPase activity of dynamin was known to be activated with acidic membrane lipids such as phosphatidylserine and the addition of NAP-22, a phosphatidylserine binding protein, inhibited the activation of the GTPase by this lipid. Since NAP-22 localizes on the presynaptic plasma membrane and on synaptic vesicles, these results suggest the participation of NAP-22 in the membrane cycling through binding to dynamin and acidic membrane lipids at the presynaptic region.

Inhibitory effect of several sphingolipid metabolites on calcineurin.

Neurons have well-developed membrane microdomains called "rafts" that are recovered as a detergent-resistant membrane microdomain fraction (DRM). NAP-22 is one of the major protein components of neuronal DRM. In a previous study, we showed that DRM-derived NAP-22 binds ganglioside and the inhibitory effect of ganglioside to calcineurin (CaN), a neuron-enriched calmodulin-regulated phosphoprotein phosphatase. Considering the important roles of CaN in neurons, identification of other cellular regulators of CaN could be a good clue to understand the molecular background of neuronal function. In this study, we screened the effect of several membrane lipid-derived molecules on the CaN activity and found sphingosine and some sphingosine-derived metabolites such as sphingosylphosphorylcholine, galactosylsphingosine (psychosine), and glucosylsphingosine, have inhibitory effect on CaN through the interaction with calmodulin.

Evaluation of paraxial forward scattering from intraocular lens with increased surface light scattering using goniophotometry and Hartmann-Shack wavefront aberrometry.

PURPOSE: To evaluate the influence of increases in light scattering on intraocular lens (IOL) surfaces on paraxial forward scattering using goniophotometry and Hartmann-Shack wavefront aberrometry. METHODS: Surface light scattering was reproduced experimentally by acceleratedly aging 4 intraocular lenses by 0, 3, 5, and 10 years each. Light scattering from both IOL surfaces was measured using Scheimpflug photography. The paraxial forward scattering from the aged IOLs was measured using a goniophotometer with a halogen light source (wavelength: 350-850 nm) and telecentric optics, and changes in the maximum intensity and full width at 10% of maximum intensity (FW10%) were evaluated. The influences on the retina image were examined using a Hartmann-Shack aberrometer (wavelength: 840 nm). The contrast and difference from the point spread function of the central centroids were evaluated. RESULTS: The mean surface light scattering from both IOL surfaces ranged from 30.0 to 118.3 computer compatible tape (CCT) and increased with each aging year. Evaluations using the goniophotometer and the Hartmann-Shack aberrometer showed no significant change in the paraxial forward scattering with the aging year (P > .45, Kruskal-Wallis test), and no association with the surface light scattering intensity was found (P > .75, Spearman rank correlation). CONCLUSION: This experimental study using aged IOLs demonstrated that surface light scattering does not influence paraxial forward scattering.

Neutrophil-lymphocyte ratio and platelet-lymphocyte ratio as predictors of wound healing failure in head and neck reconstruction.

CONCLUSIONS: In microsurgical head and neck reconstruction, a higher rate of post-operative wound complication could be predicted by a lower pre-operative neutrophil ratio (< 64.9%), neutrophil-lymphocyte ratio (NLR) (< 3.5), and platelet-lymphocyte ratio (PLR) (< 160). OBJECTIVES: To evaluate the predictor of post-operative wound complications in microsurgical head and neck reconstruction. METHODS: Patients who were undergoing tumor ablation and microsurgical reconstruction from April 2011 to March 2014 were analyzed retrospectively. The pre-operative hematological data, age, sex, co-morbidities, body mass index (BMI), adjuvant therapies, smoking, operation time, blood loss, total protein, T-stage, and Anesthesiologists Performance Status (ASA-PS) score were collected. Cases of post-operative wound healing failure were reviewed. RESULTS: One hundred and three consecutive patients were enrolled. Among these, the results of 77 patients who were younger than 70 years of age were analyzed. The distributions of the neutrophil ratio (p = .0005), lymphocyte ratio (p = .0166), monocyte ratio (p = .0341), NLR (p = .005), and PLR (p = .008) differed significantly between the patients with and without post-operative wound healing failure. Neutrophil ratio, NLR, and PLR cut-off values of 64.9, 3.5, and 160 were significantly associated with the rate of wound healing failure rate (p = .0002, .00021, .0042, respectively).

Case of acrodermatitis continua of Hallopeau following psoriasis with atypical clinical presentation.

We present a 63-year-old Japanese woman who had clinically unique symmetrical skin rashes on her lower face, inframammary area, back and extremities, with some pustules on the cheeks. Skin biopsy specimens showed typical findings of psoriasis, and Psoriasis Area and Severity Index score was 5.9. After the skin lesions were treated successfully with vitamin D3 ointment, pustules developed on the tips of the fingers and toes, with paronychial and subungual involvement. The pathology of the nail matrix was consistent with pustular psoriasis, and the patient was diagnosed with acrodermatitis continua of Hallopeau (ACH) following psoriasis with an unusual clinical presentation. ACH was well controlled with a low dose of cyclosporin. Our patient is a rare case chronologically affected by two diseases in the same category. We confirmed that ACH is a variant of pustular psoriasis, and believe that the patient could provide another clue to determining the entity of ACH.

In vitro examination of surface light scattering in hydrophobic acrylic intraocular lenses.

PURPOSE: To evaluate laboratory models using accelerated aging to assess surface light scattering in hydrophobic acrylic intraocular lenses (IOLs). SETTING: Miyata Eye Hospital, Miyazaki, Japan. DESIGN: Experimental study. METHODS: Acrysof SA60AT IOLs manufactured before optimization of the IOL production process (non-optimized IOLs) and Acrysof SN60WF IOLs that were manufactured after optimization of the production process (optimized IOLs) were examined. After the IOLs were accelerated aged corresponding to 0, 3, 5, 10, 15, and 20 years, surface light scattering was measured with a Scheimpflug camera. Formation of water aggregates below the IOL surface was observed with cryogenic focused ion-beam scanning electron microscopy. RESULTS: In the non-optimized IOLs, surface light scattering increased with aging (P<.001, R2=0.87). There was no significant increase in surface light scattering in the optimized IOLs. An increase in water aggregates with sizes of nanometer order was observed in the aged non-optimized IOLs. CONCLUSIONS: An in vitro model using accelerated aging was effective for examining the incidence of surface light scattering. The laboratory results showed suppression of surface light scattering in the IOL manufactured with the optimized process. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Cranial distraction osteogenesis for syndromic craniosynostosis: long-term follow-up and effect on postoperative cranial growth.

BACKGROUND: Although cranial distraction osteogenesis (CDO) is beneficial, few studies have reported on detailed operative procedures and postoperative cranial growth. Herein, we demonstrated the objective effectiveness of CDO in younger infants. METHODS: The study included infants who underwent primary cranial distraction for craniosynostosis. Infants who had hydrocephalus were excluded and those who underwent additional osteotomy surgeries were analysed before the subsequent procedures. The infants' computed tomography data were analysed using Mimics(®) software (Materialise, Leuven, Belgium) to calculate the cranial volumes and compare them with the Abbott curve for a normal population. We defined cranial growth gap as the difference between the subject data and normal infant data to demonstrate the perioperative effects on cranial growth. RESULTS: CDO was performed in 10 infants. The mean infant age at the time of surgery was 6.4 months (range, 24--61 months) and the mean duration of postoperative follow-up was 38.9 months (range, 24--61 months). Five infants with Crouzon syndrome and five with Apert's syndrome were included. All infants showed postoperative cranial growth, but cranial growth gap showed postoperative declines for a certain period, indicating cranial growth suppression immediately following expansion. At the last follow-up, all cases were within ±2 standard deviation (SD) compared with the normal population. We derived a formula to predict the CDO target volume using the declining cranial growth gap curve. CONCLUSIONS: CDO was applicable and suitable for younger infants requiring aggressive cranial expansion.