Exclusive expression of KANK4 promotes myofibroblast mobility in keloid tissues

Keloids are characterized by abnormal wound healing with excessive accumulation of extracellular matrix. Myofibroblasts are the primary contributor to extracellular matrix secretion, playing an essential role in the wound healing process. However, the differences between myofibroblasts involved in keloid formation and normal wound healing remain unclear. To identify the specific characteristics of keloid myofibroblasts, we initially assessed the expression levels of well-established myofibroblast markers, α-smooth muscle actin (α-SMA) and transgelin (TAGLN), in scar and keloid tissues (n = 63 and 51, respectively). Although myofibroblasts were present in significant quantities in keloids and immature scars, they were absent in mature scars. Next, we conducted RNA sequencing using myofibroblast-rich areas from keloids and immature scars to investigate the difference in RNA expression profiles among myofibroblasts. Among significantly upregulated 112 genes, KN motif and ankyrin repeat domains 4 (KANK4) was identified as a specifically upregulated gene in keloids. Immunohistochemical analysis showed that KANK4 protein was expressed in myofibroblasts in keloid tissues; however, it was not expressed in any myofibroblasts in immature scar tissues. Overexpression of KANK4 enhanced cell mobility in keloid myofibroblasts. Our results suggest that the KANK4-mediated increase in myofibroblast mobility contributes to keloid pathogenesis.

Peptide Receptor Radionuclide Therapy for Recurrent Olfactory Neuroblastoma After Cranioplasty for Surgical Infection: A Case Report

BACKGROUND

Peputide receptor radionuclide therapy with 177Lu for midgut neuroendocrine metastasis has been clinically approved as a safe treatment. Unresectable metastases of olfactory neuroblastoma have shorter survival due to insufficient effective systemic treatment.

CASE REPORT

Herein, we report a patient treated with peputide receptor radionuclide therapy for unresectable recurrent olfactory neusroblastoma following a rare cranial metastasectomy infection. A 50-year-old female patient with olfactory neuroblastoma of Kadish C was initially treated by skull base surgery plus postoperative radiotherapy following chemotherapy. Recurrent disease with neck and intracranial metastases was treated by four salvage surgeries. Surgical site infection following intracranial metastasectomy was treated with debridement and delayed cranioplasty. Peputide receptor radionuclide therapy was performed for unresectable multiple metastases after cranioplasty. Successful therapy using four cycles of peputide receptor radionuclide had neither grade 3 nor grade 4 adverse events. The patient was followed at an outpatient clinic.

CONCLUSION

Further case accrual of peputide receptor radionuclide therapy is required to develop a treatment for unresectable olfactory neuroblastoma.

Creating and Transferring an Innervated, Vascularized Muscle Flap Made from an Elastic, Cellularized Tissue Construct Developed In Situ

Reanimating facial structures following paralysis and muscle loss is a surgical objective that would benefit from improved options for harvesting appropriately sized muscle flaps. The objective of this study is to apply electrohydrodynamic processing to generate a cellularized, elastic, biocomposite scaffold that could develop and mature as muscle in a prepared donor site in vivo, and then be transferred as a thin muscle flap with a vascular and neural pedicle. First, an effective extracellular matrix (ECM) gel type is selected for the biocomposite scaffold from three types of ECM combined with poly(ester urethane)urea microfibers and evaluated in rat abdominal wall defects. Next, two types of precursor cells (muscle-derived and adipose-derived) are compared in constructs placed in rat hind limb defects for muscle regeneration capacity. Finally, with a construct made from dermal ECM and muscle-derived stem cells, protoflaps are implanted in one hindlimb for development and then microsurgically transferred as a free flap to the contralateral limb where stimulated muscle function is confirmed. This construct generation and in vivo incubation procedure may allow the generation of small-scale muscle flaps appropriate for transfer to the face, offering a new strategy for facial reanimation.

＜Editors' Choice＞ Long-term outcomes of lateral skull base reconstruction with a free omental flap and facial nerve reconstruction

In lateral skull base reconstruction, it is necessary to seal the defect in the lateral skull base, fill the dead space, and, sometimes, reconstruct the facial nerve. However, this procedure is difficult to perform with a standard musculocutaneous flap. Therefore, for such cases, an omental flap is used in our hospital because of its flexibility. In this study, we report our experience with the procedure (lateral skull base reconstruction with a free omental flap) and its long-term outcome and facial nerve reconstruction, with special focus on facial nerve recovery. This study is a technical note and a retrospective review. It was conducted in Nagoya University Hospital. Overall, 16 patients (12 women and 4 men; mean age: 55.1 years) underwent lateral skull base reconstruction with a free omental flap after subtotal temporal bone resection or lateral temporal bone resection during 2005-2017. The main outcome measures were postoperative complications and facial nerve recovery: Yanagihara score and House-Brackmann grading system. Complications included partial necrosis and minor cerebrospinal fluid leakage in 2 patients. Facial nerve recovery could be observed more than 12 months after surgery, with a mean Yanagihara score of 19.6 and House-Brackmann grade of 3.60. The free omental flap is a reliable method for lateral skull base reconstruction, especially in cases where facial nerve reconstruction is needed. To the best of our knowledge, this is the first report on facial nerve recovery after lateral skull base reconstruction.

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.

Artificial PGA/Collagen-based Bilayer Conduit in Short Gap Interposition Setting Provides Comparable Regenerative Potential to Direct Suture

The aim of this study was to evaluate whether the Nerbridge, an artificial polyglycolic acid conduit with collagen matrix, is comparable to direct nerve suture in a rat sciatic nerve injury model in a short-gap interposition (SGI) setting.

Methods

Sixty-six female Lewis rats were randomly divided into the sham group (n = 13); no reconstruction (no-recon) group (n = 13; rat model with 10 mm sciatic nerve defect); direct group (n = 20; rat sciatic nerve injury directly connected by 10-0 Nylon); and SGI group (n = 20; sciatic nerve injury repaired using 5-mm Nerbridge). Motor function and histological recovery were evaluated. The sciatic nerve and gastrocnemius muscle were harvested for quantification of the degree of nerve regeneration and muscle atrophy.

Results

The SGI and direct groups achieved equal recovery in both functional and histological outcomes. At weeks 3 and 8 postsurgery, there was a significant improvement in the sciatic functional index of the SGI group when compared with that of the no-recon group (P < 0.05). Furthermore, the direct and SGI groups had less muscle atrophy at 4 and 8 weeks postsurgery compared with the no-recon group (P < 0.05). The axon density and diameter at the distal site in the SGI group were significantly higher than that in the no-recon group and comparable to that in the direct and sham groups.

Conclusion

An artificial nerve conduit has equal potential as direct suture in motor nerve reconstruction when used in the SGI setting.

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.

Colon cancer with extensive invasion of the abdominal wall treated with neoadjuvant chemotherapy and a free anterolateral thigh flap

Background

The treatment of locally advanced colon cancer is challenging, particularly when there is invasion of the abdominal wall. In such cases, balancing the securing of margins and sufficiently repairing abdominal wall defects is important, but difficult when the extent of invasion is large.

Case presentation

A 34-year-old male was referred to our hospital with abdominal pain and diagnosed with obstructive transverse colon cancer. He had undergone ileo-sigmoid colostomy at his previous hospital. The tumor was massive and invaded the abdominal wall (maximum diameter: approximately 12 cm), and was accompanied by regional lymph node swelling. No distant metastasis was detected. We diagnosed the tumor as cT4bN2bM0 Stage IIIC locally advanced transverse colon cancer and planned neoadjuvant chemotherapy. After two courses of FOLFOXIRI (5-fluorouracil, leucovorin, oxaliplatin, and irinotecan), he developed an entero-cutaneous fistula due to tumor penetration and required emergency diverting ileostomy construction. After the procedure, contrast-enhanced computed tomography showed good tumor shrinkage. As a result, the planned chemotherapy was canceled and he underwent radical resection of the tumor. En bloc extended right hemicolectomy was performed with excision of the fistula, ensuring a sufficient margin. The post-excision defect at the anterior abdominal wall involved 11 × 16 cm of fascia and 6 × 9 cm of skin located in the middle of the abdomen. A free anterolateral thigh flap was harvested from the right thigh and vascular pedicle was anastomosed to the right gastroepiploic artery and vein. The fascia lata, which was included in the anterolateral thigh flap, was sutured onto the abdominal wall fascia as inlay fashion to reconstruct the abdominal wall defect. Histopathology revealed moderately differentiated adenocarcinoma of the colon with no tumor cells in the abdominal wall tissue [post-chemotherapeutic state, therapy effect: Grade 1b; Stage IIA (ypT3N0M0)]. All resected margins of the specimen were free from adenocarcinoma. He was discharged on postoperative day 16.

Conclusion

We report a case of colon cancer extensively invading the abdominal wall, which was completely resected. The abdominal wall defect was reconstructed with a free anterolateral thigh flap after tumor shrinkage with neoadjuvant chemotherapy. We present an efficient strategy for managing locally advanced colon cancer with extensive abdominal wall invasion.

Upper thoracic empyema and concomitant superior vena cava syndrome treated with reconstructive surgery using a pedicled omental flap

Superior vena cava (SVC) syndrome refers to a constellation of symptoms secondary to obstruction of blood flow through the SVC. In this condition, venous blood that usually drains into the SVC is diverted into the inferior vena cava (IVC) via collateral veins. Reconstructive surgery is challenging in such cases owing to the anomalous venous system. In this case report, we describe reconstructive surgery using a pedicled omental flap in a patient with upper thoracic empyema and concomitant SVC syndrome. A 68-year-old man underwent resection of malignant thymoma, the bilateral brachiocephalic veins, and a part of the right upper lobe, followed by polytetrafluoroethylene (PTFE) graft placement for venous system reconstruction, 2 years prior to presentation. He developed postoperative upper thoracic cavity empyema, which necessitated PTFE graft removal. Although the infection was controlled after 2 months, multiple right upper lobe pulmonary fistulas persisted, and the patient was referred to our department for further evaluation. Contrast-enhanced computed tomography revealed SVC syndrome characterized by SVC obstruction and consequent drainage of venous blood from the upper trunk into the IVC via collateral vessels. We debrided necrotic and infected tissues, and a pedicled omental flap was placed for upper lobe fistula coverage. The patient showed an uncomplicated postoperative course, and no recurrent empyema or pulmonary fistulas were observed 3 years postoperatively. Flaps associated with the SVC system show high venous pressures. The use of a pedicled omental flap was deemed feasible because this graft reaches the upper thorax even though it is associated with the IVC system.

Surgical Classification of Radical Temporal Bone Resection and Transcranial Tympanotomy: A Retrospective Study from the Neurosurgical Perspective

OBJECTIVE

To review the authors' surgical experience with radical temporal bone resection (TBR) with an emphasis on the classification of skull base osteotomy and transcranial tympanotomy (TCT) that is required for middle ear transection.

METHODS

We reviewed the records of 25 patients who underwent radical TBR at our facilities between 2011 and 2020.

RESULTS

The osteotomy line of radical TBR was divided into 3 segments: anterior (A), medial (M), and posterior (P). Each segment was further classified as follows: A1, through the glenoid fossa (1 patient); A2, in front of the glenoid fossa (23 patients); A3, through the greater wing of the sphenoid bone (1 patient); M1, through the middle ear (16 patients); M2, through the inner ear (9 patients); P1, through the mastoid (9 patients); and P2, through the posterior cranial fossa (16 patients). The M segment was significantly associated with operation time and intraoperative blood loss. In all patients with M1 osteotomy, TCT was performed; TCT was classified into superior and far posterior approaches. A superior approach was performed in all 16 patients, whereas the far posterior approach was performed in only 7 patients with both M1 and P2 osteotomy.

CONCLUSIONS

Our newly proposed osteotomy classification of radical TBR is suitable for minute but clinically important adjustment of the osteotomy line. TCT is an indispensable technique for M1 osteotomy; our newly proposed classification expands our understanding of TCT and how to incorporate this technique into radical TBR.

Biological characterization of adipose-derived regenerative cells used for the treatment of stress urinary incontinence

OBJECTIVE

To assess the characteristics of adipose-derived regenerative cells, and provide supportive data explaining the mechanism of efficacy observed for the use of these cells in the treatment of stress urinary incontinence.

METHODS

Adipose tissues were harvested by abdominal liposuction from healthy donors and patients with stress urinary incontinence. Adipose-derived regenerative cells were isolated from tissues using the Celution system, and assessed for their characteristics and ability to differentiate into smooth muscle cells.

RESULTS

Adipose-derived regenerative cells isolated by the Celution system developed into fibroblastic colonies. Flow cytometric analysis of adipose-derived stem cell markers showed that adipose-derived regenerative cells were positive for CD34 and CD44, and negative for CD31. Immunofluorescence staining after differentiation showed that colony-forming cells were positive for alpha-smooth muscle actin, calponin and desmin, which are smooth muscle cell markers. A cytokine release assay showed that adherent cells secreted cytokines associated with angiogenesis, including vascular endothelial growth factor-A, angiopoietin-2 and placental growth factor.

CONCLUSIONS

Adipose-derived regenerative cells collected by the Celution system might have clonogenic capacity and an angiogenetic function. These properties might contribute to the mechanisms through which regenerative cell therapy by periurethral injection of autologous adipose-derived regenerative cells ameliorates stress urinary incontinence.

Therapeutic angiogenesis using autologous adipose-derived regenerative cells in patients with critical limb ischaemia in Japan: a clinical pilot study

Adipose-derived regenerative cell (ADRC) is a promising alternative source of autologous somatic stem cells for the repair of damaged tissue. This study aimed to assess the safety and feasibility of autologous ADRC implantation for therapeutic angiogenesis in patients with critical limb ischaemia (CLI). A clinical pilot study—Therapeutic Angiogenesis by Cell Transplantation using ADRCs (TACT-ADRC) study—was initiated in Japan. Adipose tissue was obtained by ordinary liposuction method. Isolated ADRCs were injected into the ischaemic limb. We performed TACT-ADRC procedure in five patients with CLI. At 6 months, no adverse events related to the TACT-ADRC were observed. No patients required major limb amputation, and ischaemic ulcers were partly or completely healed during the 6-month follow-up. In all cases, significant clinical improvements were seen in terms of rest pain and 6-min walking distance. Numbers of circulating CD34⁺ and CD133⁺ cells markers of progenitor cell persistently increased after ADRC implantation. The ratio of VEGF-A₁₆₅b (an anti-angiogenic isoform of VEGF) to total VEGF-A in plasma significantly decreased after ADRC implantation. In vitro experiments, cultured with ADRC-conditioned media (CM) resulted in increased total VEGF-A and decreased VEGF-A₁₆₅b in C2C12 cells, but not in macrophages. ADRC-CM also increased CD206⁺ cells expression and decreased TNF-α in macrophages. Autologous ADRC implantation was safe and effective in patients with CLI and could repair damaged tissue via its ability to promote angiogenesis and suppress tissue inflammation.

Functional evaluation following deltoid muscle resection in patients with soft tissue sarcoma

BACKGROUND

The present study aimed to determine functional outcomes in patients undergoing deltoid muscle resection for soft tissue sarcoma.

METHODS

Between 2002 and 2014, 18 patients with soft tissue sarcoma of the shoulder who underwent wide resection including the deltoid muscle, and were followed up for more than 12 months, were retrospectively included in the study. In all, 11 patients were male and 7 were female. The median age was 59 years, median follow-up duration was 37 months. The extent of resection of deltoid muscle, with or without rotator cuff damage, reconstruction methods, adjuvant therapy, oncological outcomes, and the International Society of Limb Salvage (ISOLS) score as functional outcomes were analyzed.

RESULTS

Six patients underwent total resection, and twelve underwent partial resections of deltoid muscle. The rotator cuff was resected in four patients. Soft tissue reconstruction was performed in 17 patients using a pedicled latissimus dorsi muscle flap. Two local recurrences and three distant metastases occurred during follow-up. Median overall survival was 72 months. The mean ISOLS score was 25.0 points (±4.6points). Univariate analysis revealed that there was no significant difference in ISOLS score regarding the extent of deltoid muscle resection. Multivariate analysis identified only combined resection of the rotator cuff as a significant prognostic factor for poor functional outcomes (P < 0.001).

CONCLUSIONS

The extent of resection of the deltoid muscle might not affect the functional outcomes determined by ISOLS score. If the rotator cuff is resected concurrently, satisfactory functional outcomes might not be obtained.

Correlation between blood flow, tissue volume and microvessel density in the flap

The purpose of this study was to assess the correlation between tissue volume and blood flow of the flap in an animal model. Using animal model, tissue volume can be attenuated, and precise change of blood flow could be evaluated. We further investigate the relationship between blood flow and vascular density in the tissue. In this study, we assessed flap conductance (ml/min/mm Hg) as to evaluate the conductivity of blood flow into the flap. Japanese white rabbit was used (n = 7) for this study. The amount of blood flow of jejunal and latissimus dorsi muscle (LD) flaps was measured while removing the distal portion of the flap sequentially. Conductance at each time was calculated from blood pressure and blood flow volume. The tissue volume at each time was also measured. The correlation between conductance and volume was analyzed using a linear mixed model. Immunohistochemical evaluation of microvessel densities (MVD) in these tissues was also performed for CD31/PECAM1 positive area. Conductance and tissue volume were significantly correlated in both jejunal and LD flaps. As the volume increases by 1 cm³, the conductance increased significantly by 0.012 ml/min/mm Hg in jejunum, and by 0.0047 ml/min/mm Hg in LD. Mean MVD was 1.15 ± 0.52% in the jejunum and 0.37 ± 0.29% in the LD muscle. In this study, we revealed that flap conductance is proportional to volume and proportional constant is different between the type of tissue. It suggests that the difference of MVD creates the unique conductance of each tissue.

Repair of temporal branch of the facial nerve with novel polyglycolic acid-collagen tube: a case report of two cases

Autologous nerve transplantation has been the gold standard in the treatment of facial nerve injury, however it has not been achieved satisfactory result and needs donor sacrifice. A polyglycolic acid collagen conduit (Nerbridge, Toyobo Co., Japan) has the potential to compare to or exceed autologous nerve grafts in promoting nerve regeneration. Here we report two cases of traumatic temporal facial nerve injury repairs with Nerbridge. The severed temporal branch of the facial nerve was repaired with Nerbridge conduits in two patients. Recovery of movement was assessed by clinical photography and needle electromyography. The frontal muscle started moving five months postoperatively in both cases. Electromyography at twelve months showed polymorphic electric discharge, suggesting connection of the injured nerve to the frontal muscle. In the final results, each patient had good eyebrow elevation distance and moderate forward gaze recovery in comparison to their healthy sides. Considering that facial nerves are reported to recover incompletely even in autologous nerve graft repair cases, our two cases showed reasonable recovery comparable to nerve autografting. The Nerbridge conduit is a promising alternative to standard treatments for facial nerve recovery.

Erratum: Increased Defect Size is Associated with Increased Complication Rate after Free Tissue Transfer for Midanterior Skull-Base Reconstruction

[This corrects the article DOI: 10.1055/s-0038-1676777.].

Skull Base Invasion Patterns of Malignant Head and Neck Tumors: A Neurosurgical Perspective

Objective  Craniofacial resection (CFR) and temporal bone resection (TBR) on malignant head and neck tumors (MHNTs) invading skull base require accurate and precise determination of the tumor invasion. We investigated tumor skull base invasion patterns and surgical results in CFR and TBR cases. Methods  We performed either CFR or TBR for 75 selected patients with the possibility of en bloc resection over the period between 2011 and 2018. The medical charts of the selected patients were reviewed. Results  Primary tumor onset site (TOS) groups were: (1) nasal cavity/ethmoid sinus, 20 cases; (2) orbit, 10 cases; (3) maxillary sinus, 28 cases; and (4) external ear/temporomandibular joint, 17 cases. Grades for tumor invasion depth (TID) included: (I) extracranial invasion and skull base bone invasion; (II) extradural invasion; or (III) intradural invasion. Patients in groups 1 and 2 had a significantly higher frequency of grade II and III invasions than patients in groups 3 and 4. The main invasion site was nasal cavity superior wall and ethmoid sinus superior wall for group 1 tumors, orbit superior wall, and lateral skull base sphenoid bone for group 2 and 3 tumors, and lateral skull base temporal bone for group 4 tumors. Positive resection margins represented a significant negative prognostic factor. TID and TOS did not affect skull base margin status. Conclusion  Skull base invasion of MHNTs exhibits certain fixed patterns in sites susceptible to invasion based on the TOS. The frequencies of extradural and intradural invasions differed, indicating the importance for accurate preoperative tumor evaluation.

Prospective Evaluation of Health-Related Quality of Life in Patients Undergoing Anterolateral Craniofacial Resection with Orbital Exenteration

Objective  This study was aimed to evaluate health-related quality of life in patients undergoing anterolateral craniofacial resection (AL-CFR) with orbital exenteration (OE) for malignant skull base tumors and to investigate the effects of early psychiatric intervention. Design  Present study is a prospective, observational study. Setting  The study took place at the hospital department. Participants  Twenty-six consecutive patients were selected who underwent AL-CFR with OE at our hospital between 2005 and 2015. Main Outcome Measures  Health-related quality of life was assessed preoperatively and 3, 6, 12, and 24 months after surgery using the Hospital Anxiety and Depression Scale (HADS) and medical outcomes study 8-items Short Form health survey (SF-8). In all cases, psychiatric intervention was organized by the consultation liaison psychiatry team preoperatively and postoperatively. Results  Ten (38.0%) of the 26 patients died and 16 (62.0%) were alive and disease-free at the end of the study. The 3-year overall and disease-free survival rates were 64.9% and 53.3%, respectively. Twenty-one patients (80.8%) developed psychiatric complications after surgery and needed treatment with psychotropic medication. Before surgery, 28% of patients had HADS scores ≥8 for anxiety and 20% had scores ≥8 for depression. Seven of the eight items in the SF-8 were significantly lower than those for the general Japanese population. However, scores for all the SF-8 items gradually improved during postoperative follow-up, reaching approximately 50 points, which is the national standard value, at 2 years after surgery. Conclusions  Craniofacial resection with OE was feasible and well tolerated in patients with malignant skull base tumors who received early psychiatric intervention to decrease the considerable psychological impact of this procedure.

Increased Defect Size is Associated with Increased Complication Rate after Free Tissue Transfer for Midanterior Skull-Base Reconstruction

Objective  Complications after skull-base reconstruction are often problematic. We consider that local factors, for example, localization of defect areas are possible risk factors. This study aimed to investigate our case series of skull-base reconstructions in our institution and to identify local risk factors that predispose to wound complications. Design  This study is presented as a retrospective study. Setting  Research work was took place at Nagoya University Hospital. Participants  Forty-eight patients who had undergone reconstruction after midanterior skull-base resection between January 2004 and December 2015 were included in this study. Defects apart from the skull-base were categorized into nasal and paranasal cavity (N), orbit (O), palate (P), and facial skin (S). Postoperative local complications including cerebrospinal fluid (CSF) leakage, local infection, wound dehiscence (fistula in face or palate), and flap necrosis (partial or total) were investigated. Main Outcome Measures  Main outcome measures were postoperative complications in patients with each defect. Results  Apart from the skull-base, defects included 28 ONP (58.3%), 10 ONPS (20.8%), 3 ON (6.3%), 3 ONS (6.3%), 1 NP (2.1%), and 1 OS (2.1%). Comparison based on numbers of resected regions revealed that a significantly higher complication rate was seen in patients with four resected regions than in those with three regions (90.0% vs. 45.2%, p  < 0.05). Conclusion  There was a trend suggesting that more resected regions corresponded to a greater risk of complications in midanterior skull-base reconstruction. Reconstructive surgeons need to carefully consider the reconstruction of such complicated defects.

Liposuction for autologous adipose-derived regenerative cells: Preliminary results of donor-site complications in male stress urinary incontinence

Objectives

Liposuction is now applied to harvest autologous adipose-derived regenerative cells in the regenerative medicine. Although liposuction is highly safe for females who generally have larger fat deposits, liposuction has some potential risks for donor-site complications in the case of aged male patients. The purpose of our study was to review the complications of liposuction of the aged male patients who have undergone cell therapy for stress urinary incontinence.

Methods

Sixteen male patients (mean age, 74 years old) with persistent stress urinary incontinence were included in this study. Approximately 250 mL of adipose tissue was harvested using a syringe attached to the cannula. Postoperative complications were recorded and graded according to the Common Terminology Criteria for Adverse Events (CTCAE), version 4.0.

Results

Average liposuction time was 57.4 min. No major complications were observed. However, there were some minor complications: bruising, numbness, contour irregularities, firmness, and scarring. These complications were CTCAE Grade 1 in all cases. The complications, except for the scarring, became unnoticeable within 6 months in all cases.

Conclusion

Liposuction takes time and has some minor donor-site complications for stem cell therapy in aged male stress urinary incontinence patients.

Nuss procedure for patients with pectus excavatum with a history of intrathoracic surgery

BACKGROUND

The aim of this study was to demonstrate the feasibility and safety of the Nuss procedure for patients with pectus excavatum (PE) with a history of intrathoracic surgery.

PATIENTS

From April 2010 to December 2013, we performed 6 cases of PE repair in patients with a history of intrathoracic surgery. The causes of previous operations were congenital cystic adenomatoid malformation in 4 patients and congenital diaphragmatic hernia in 2. The patients' median age was 5 years (range, 4-9 years) and median preoperative pectus severity index was 4.63 (range, 3.42-10.03). Their intraoperative and postoperative courses were reviewed retrospectively.

RESULTS

The mean overall operation time was 127.5 ± 17.0 minutes, and the mean operation time for endoscopic pneumolysis was 28.8 ± 12.3 minutes. Intraoperative exploration for pleural adhesion revealed that the endoscopic approach in the previous operation was associated with low pleural adhesion, and the open thoracotomy or laparotomy approach was associated with low to high pleural adhesion. One patient developed a pneumothorax on the first postoperative day. All the other patients had uneventful postoperative courses. All the patients received bar removal 2-3 years after bar insertion. One patient developed atelectasis after bar removal. All the other patients had an uneventful postoperative course. The mean postoperative follow-up time after bar removal was 20.1 ± 14.7 months.

CONCLUSIONS

History of intrathoracic surgery seems not a contraindication for the Nuss procedure. However, perioperative complications should be carefully monitored in both the bar insertion and removal operations.

Role of transcranial sphenoidotomy in skull base surgery: classification of surgical techniques based on the surgical anatomy of the sphenoid sinus

OBJECTIVE

Although sphenoidotomy is more commonly performed via the transnasal approach than via the transcranial approach, transcranial sphenoidotomy (TCS) remains indispensable for en bloc resection of locally advanced sinonasal malignant tumors (SNMTs) extending to the skull base. TCS also enables transsphenoidal transposition of the temporoparietal galeal flap (TPGF) to compensate for the lack of vascularized reconstructive tissue after endoscopic transnasal skull base surgery. The objective of this study was to review the authors' surgical experience using TCS with an emphasis on the surgical anatomy of the sphenoid sinus and on the purpose of TCS. Relevant anatomy is further illustrated through cadaveric dissection and photo documentation.

METHODS

The authors reviewed the records of 50 patients who underwent TCS at the Nagoya University Hospital, Fukushima Medical University Hospital, or Aichi Medical University Hospital over the course of 7 years (between January 2011 and November 2017). The authors also performed cadaveric dissection in 2 adult cadaveric skull base specimens.

RESULTS

Of the 50 patients included in this study, 44 underwent craniofacial resection (CFR) for en bloc resection of SNMTs involving the anterior and/or lateral skull base, and 6 underwent transsphenoidal transposition of the TPGF flap. The authors categorized the TCS procedures according to the portion of the sphenoid sinus wall involved (i.e., superior, lateral, and superolateral). Superior sphenoidotomy was used in patients requiring anterior CFR. Lateral sphenoidotomy was further divided into 2 subtypes, with type 1 procedures performed for the transsphenoidal transpositioning of the TPGF, and type 2 procedures used in patients requiring lateral CFR. Superolateral sphenoidotomy was used in anterolateral CFR.

CONCLUSIONS

TCS still represents a useful tool in the armamentarium of neurosurgeons treating central skull base lesions. The newly proposed surgical classification facilitates a profound understanding of TCS and how to incorporate this technique into clinical practice.

＜Editors' Choice＞ Effect of postoperative doxorubicin administration on ischemic wound healing

Some patients undergo postoperative chemotherapy despite showing impaired wound healing after a major surgery. We speculated that postoperative chemotherapy further delays wound healing in these patients. This study aimed to compare the effects of doxorubicin (DXR) in ischemic skin flap and normal incisional wound models after surgery. A 2-cm incisional wound was made in group 1 rats, and saline was injected intravenously, following surgery on the same day. Incisional wound was made in group 2–5 rats, and 8 mg/kg DXR was injected intravenously, following surgery on the same day and after 7, 14, and 21 days respectively. H-shaped double flaps were made in group 6 rats, and saline was injected intravenously, following surgery on the same day. Flaps were made in group 7–10 rats, and 8 mg/kg DXR was injected intravenously, following surgery on the same day and after 7, 14, and 21 days respectively. On days 7, 14, 21, and 28 after surgery, the suture wounds were removed, tensile wound strengths were measured, and tissue samples were collected for histopathological evaluation. The tensile strength was significantly lower in the DXR-treated groups than in the control groups for both ischemic skin flaps and incision wounds. Additionally, the cross effect between DXR and ischemia was not significant. On pathological examination, DXR showed atrophic skin changes and degeneration of skin appendages on days 14–21 after the surgery in both the models. DXR decreased the wound tensile strength and caused an atrophic change in the ischemic wound.

Computed tomographic assessment of autologous fat injection augmentation for vocal fold paralysis

Objective

To perform a quantitative computed tomography (CT) assessment of short‐ and long‐term outcomes of autologous fat injection augmentation in patients with unilateral vocal fold paralysis.

Study Design

Retrospective case series.

Methods

Twelve patients who had undergone autologous fat injection augmentation for unilateral vocal fold paralysis in our hospital between 2011 and 2015 were enrolled in this study. The autologous fat for injection was acquired from periumbilical subcutaneous tissue and was injected orally using a special‐purpose laryngeal injection needle. To evaluate the injected fat at the follow‐up assessments, CT was performed at several times after surgery in clinical practice. All thin‐section CT images were transferred to a workstation, and the volume of the injected fat was calculated.

Results

Patients comprised 6 men and 6 women with a mean age at the time of surgery of 62.9 years (range, 46–82 years). The actual injected fat volume was 1.1–2.5 ml (mean, 1.6 ml). In seven patients assessed by CT two days after surgery, the average residual rate of the injected fat was 63.9%. The mean residual rates of the injected fat were 30.0% at 3 months, 33.7% at 6 months, 29.2% at 12 months, and 32.0% at 24 months.

Conclusions

Although the injected fat volume decreased within the first three months and the residual rate of the injected fat was 30.0% at three months after injection, the residual fat volume remained at the same level for 24 months after injection.

Level of Evidence

4

Design of a single-arm clinical trial of regenerative therapy by periurethral injection of adipose-derived regenerative cells for male stress urinary incontinence in Japan: the ADRESU study protocol

BACKGROUND

Male stress urinary incontinence is a prevalent condition after radical prostatectomy. While the standard recommendation for the management of urine leakage is pelvic floor muscle training, its efficacy is still unsatisfactory. Therefore, we have focused on regenerative therapy, which consists of administering a periurethral injection of autologous regenerative cells from adipose tissue, separated using the Celution® system. Based on an interim data analysis of our exploratory study, we confirmed the efficacy and acceptable safety profile of this treatment. Accordingly, we began discussions with Japanese regulatory authorities regarding the development of this therapy in Japan. The Ministry of Health, Labour and Welfare suggested that we implement a clinical trial of a new medical device based on the Pharmaceutical Affaires Act in Japan. Next, we discussed the design of this investigator-initiated clinical trial (the ADRESU study) aimed at evaluating the efficacy and safety of this therapy, in a consultation meeting with the Pharmaceuticals and Medical Device Agency.

METHODS

The ADRESU study is an open-label, multi-center, single-arm study involving a total of 45 male stress urinary incontinence patients with mild-to-moderate urine leakage persisting more than 1 year after prostatectomy, in spite of behavioral and pharmacological therapies. The primary endpoint is the rate of patients at 52 weeks with improvement of urine leakage volume defined as a reduction from baseline greater than 50% by 24-h pad test. Our specific hypothesis is that the primary endpoint result will be higher than a pre-specified threshold of 10%.

DISCUSSION

The ADRESU study is the first clinical trial of regenerative treatment for stress urinary incontinence by adipose-derived regenerative cells using the Celution® system based on the Japanese Pharmaceutical Affaires Act. We will evaluate the efficacy and safety in this trial to provide an adequate basis for marketing approval with the final objective of making this novel therapy widely available for Japanese patients.

TRIAL REGISTRATION

This trial was registered at the University Hospital Medical information Network Clinical Trial Registry (UMIN-CTR Unique ID: UMIN000017901 ; Registered July 1, 2015) and at ClinicalTrials.gov (ClinicalTrials.gov Identifier: NCT02529865 ; Registered August 18, 2015).

Use of a pedicled omental flap to reduce inflammation and vascularize an abdominal wall patch

BACKGROUND

Although a variety of synthetic materials have been used to reconstruct tissue defects, these materials are associated with complications such as seromas, fistulas, chronic patient discomfort, and surgical site infection. While alternative, degradable materials that facilitate tissue growth have been examined. These materials can still trigger a foreign body inflammatory response that can lead to complications and discomfort.

MATERIALS AND METHODS

In this report, our objective was to determine the effect of placing a pedicled omental flap under a biodegradable, microfibrous polyurethane scaffold serving as a full-wall thickness replacement of the rat abdominal wall. It was hypothesized that the presence of the omental tissue would stimulate greater vascularization of the scaffold and act to reduce markers of elevated inflammation in the patch vicinity. For control purposes, a polydimethylsiloxane sheet was placed as a barrier between the omental tissue and the overlying microfibrous scaffold. Both groups were sacrificed 8 wk after the implantation, and immunohistological and reverse transcription polymerase chain reaction (RT-PCR) assessments were performed.

RESULTS

The data showed omental tissue placement to be associated with increased vascularization, a greater local M2/M1 macrophage phenotype response, and mRNA levels reduced for inflammatory markers but increased for angiogenic and antiinflammatory factors.

CONCLUSIONS

From a clinical perspective, the familiarity with utilizing omental flaps for an improved healing response and infection resistance should naturally be considered as new tissue engineering approaches that are translated to tissue beds where omental flap application is practical. This report provides data in support of this concept in a small animal model.

Preoperative surgical simulation and validation of the line of resection in anterolateral craniofacial resection of advanced sinonasal sinus carcinoma

BACKGROUND

The purpose of this study was to assess the usefulness and accuracy of preoperative 3D virtual simulation of anterolateral craniofacial resection in cases of advanced sinonasal sinus carcinoma.

METHODS

Seven patients with advanced (T4 classification) sinonasal sinus carcinoma who underwent anterolateral craniofacial resection in our hospital between 2011 and 2013 were included in this study. Postsimulation CT images were fused with postoperative CT images and differences between the planned and actual osteotomy were measured in 3 regions of the skull base.

RESULTS

The differences ranged from 0 mm to 5.8 mm (average, 3.1 mm) at the inferior wall of the cavernous sinus, from 0.8 mm to 8.3 mm (average, 3.5 mm) at the inferior wall of the sphenoid sinus, and from 0 mm to 13.6 mm (average, 2.3 mm) in the palatine bone.

CONCLUSION

Preoperative 3D virtual surgical simulation and postoperative feedback can contribute to training for surgeons. © 2016 Wiley Periodicals, Inc. Head Neck 39: 512-519, 2017.

Effects of Tissue Component Volumes on Vascular Resistance in Free Flaps

Background A successful free flap transfer is achieved, in part, by having a thorough understanding of vascular anatomy and blood flow dynamics. We previously reported that vascular resistance differs by type of free flap. To test the hypothesis that the difference reflects the proportion of tissue components within free flaps, we calculated blood flow and vascular resistance for free flaps in which we determined the volume of each tissue component. Methods Measurements and calculations were made for 40 free flap transfers performed at our hospital: 7 radial forearm flaps, 14 anterolateral thigh flaps, and 19 rectus abdominis myocutaneous flaps. Results The vascular resistance of free flaps was inversely related to the volume of each tissue component. Univariate regression analysis revealed that muscle volume correlated most closely with resistance (r = 0.881), followed by skin (r = 0.622), and fat (r = 0.577). Multiple regression analysis confirmed the relationship between combined muscle and fat volume and resistance (R² = 0.865). Conclusions A strong inverse correlation exists between vascular resistance and combined muscle and fat tissue volume in flaps. It may be helpful to consider these relationships when making decisions regarding choice of free flap and recipient vessels.

Operative wound-related complications after cranial revascularization surgeries

OBJECT

Intracranial revascularization surgeries are an effective treatment for moyamoya disease and other intracranial vascular obliterative diseases. However, in some cases, wound-related complications develop after surgery. Although the incidence of wound complication is supposed to be higher than that with a usual craniotomy, this complication has rarely been the focus of studies in the literature that report the outcomes of revascularization surgeries. Here, the relationship between intracranial revascularization surgeries and their complications is statistically assessed.

METHODS

Between October 2004 and February 2010, 71 patients were treated using cerebral revascularization surgeries on 98 sides of the head. The relationship between wound complications and operative technique was retrospectively assessed. Multivariate logistic regression analysis was performed to identify the risk factors of wound complication, including operative technique, age, sex, diabetes mellitus (DM), hypertension, hyperlipidemia, and smoking history.

RESULTS

In total, there were 21 (21.4%) operative wound complications. Of these 21 complications, there were 14 (66.7%) minor complications and 7 (33.3%) major complications. No statistically significant relationship was found between wound complications and any surgical procedure. A trend toward severer complications was demonstrated for the procedures that used both STA branches (“double” procedures) in comparison with the procedures that used only 1 STA branch (“single” procedures, p = 0.016, Cochran-Armitage trend test). Multivariate logistic regression analysis also revealed that double procedures demonstrated a significantly higher incidence of wound complications than single procedures (OR 3.087, p = 0.048). DM was found to be a risk factor for wound complication (OR 9.42, p = 0.02), but age, sex, hypertension, and hyperlipidemia were not associated with the incidence of complications. Even though the blood supply to the scalp is abundant due to 5 arteriovenous systems, sometimes cutaneous necrosis develops after intracranial revascularization surgeries. The galeal blood supply is thought to be crucial for preventing wound-related complications. Special care is also thought to be required for DM patients.

CONCLUSIONS

Revascularization surgeries seemed to demonstrate a higher risk of wound-related complications. Double-type procedures, which use both branches of the STA, and a history of DM were found to be risk factors for wound-related complications. Attention should be paid to the design of the galeal incision and vessel harvest line. Also, special attention should be paid to patients with DM.

Does a muscle flap accelerate wound healing of gastric wall defects compared with an omental flap?

INTRODUCTION

Most often used for reconstruction at superficial sites, a muscle flap recently was reported to promote clinical wound healing in a duodenal defect. We therefore examined whether a muscle flap could promote wound healing comparably to an omental flap in rats with gastric wall defects.

METHODS

After perforation of the centre of the anterior gastric wall, rats were divided into 2 groups. In the muscle group, a muscle flap was fixed to the defect; in the omentum group, an omental flap was placed over the defect. We histopathologically compared tissue responses during gastric wall healing.

RESULTS

While stratified villi had completely covered the defect by day 7 in both groups, scar maturation differed. Scar tissue persisted in the muscle group, but was gradually replaced by adipose tissue in the omentum group.

DISCUSSION

Both muscle and omental flaps accelerated gastric wall wound healing.

CONCLUSION

A muscle flap is an excellent alternative for repair of gastric defects when no omental flap is available.

Surgical correction of microstomia in a patient with antilaminin 332 mucous membrane pemphigoid

Microstomia is a term used to describe a small oral aperture. Most of the reported cases are caused by scar contracture after facial trauma, burn injury, and tumor excision. We experienced a rare case of microstomia in a patient with antilaminin 332 mucous membrane pemphigoid, which was an acquired autoimmune disease and showed blisters and erosive lesions mainly on the mucous membranes. The patient had recurrent aphthous stomatitis and presented microstomia caused by scar contracture of oral mucosa. We surgically corrected microstomia by 5-flap Z-plasty for commissuroplasty and 2 Z-plasty of both upper and lower lips for an enlargement of oral aperture. The patient could achieve an enough oral aperture and was satisfied with the result. There was no recurrence of microstomia for 2 years.

The effect of polymer degradation time on functional outcomes of temporary elastic patch support in ischemic cardiomyopathy

Biodegradable polyurethane patches have been applied as temporary mechanical supports to positively alter the remodeling and functional loss following myocardial infarction. How long such materials need to remain in place is unclear. Our objective was to compare the efficacy of porous onlay support patches made from one of three types of biodegradable polyurethane with relatively fast (poly(ester urethane)urea; PEUU), moderate (poly(ester carbonate urethane)urea; PECUU), and slow (poly(carbonate urethane)urea; PCUU) degradation rates in a rat model of ischemic cardiomyopathy. Microporous PEUU, PECUU or PCUU (n = 10 each) patches were implanted over left ventricular lesions 2 wk following myocardial infarction in rat hearts. Infarcted rats without patching and age-matched healthy rats (n = 10 each) were controls. Echocardiography was performed every 4 wk up to 16 wk, at which time hemodynamic and histological assessments were performed. The end-diastolic area for the PEUU group at 12 and 16 wk was significantly larger than for the PECUU or PCUU groups. Histological analysis demonstrated greater vascular density in the infarct region for the PECUU or PCUU versus PEUU group at 16 wk. Improved left ventricular contractility and diastolic performance in the PECUU group was observed at 16 wk compared to infarction controls. The results indicate that the degradation rate of an applied elastic patch influences the functional benefits associated patch placement, with a moderately slow degrading PECUU patch providing improved outcomes.

Non-invasive characterization of polyurethane-based tissue constructs in a rat abdominal repair model using high frequency ultrasound elasticity imaging

The evaluation of candidate materials and designs for soft tissue scaffolds would benefit from the ability to monitor the mechanical remodeling of the implant site without the need for periodic animal sacrifice and explant analysis. Toward this end, the ability of non-invasive ultrasound elasticity imaging (UEI) to assess temporal mechanical property changes in three different types of porous, biodegradable polyurethane scaffolds was evaluated in a rat abdominal wall repair model. The polymers utilized were salt-leached scaffolds of poly(carbonate urethane) urea, poly(ester urethane) urea and poly(ether ester urethane) urea at 85% porosity. A total of 60 scaffolds (20 each type) were implanted in a full thickness muscle wall replacement in the abdomens of 30 rats. The constructs were ultrasonically scanned every 2 weeks and harvested at weeks 4, 8 and 12 for compression testing or histological analysis. UEI demonstrated different temporal stiffness trends among the different scaffold types, while the stiffness of the surrounding native tissue remained unchanged. The changes in average normalized strains developed in the constructs from UEI compared well with the changes of mean compliance from compression tests and histology. The average normalized strains and the compliance for the same sample exhibited a strong linear relationship. The ability of UEI to identify herniation and to characterize the distribution of local tissue in-growth with high resolution was also investigated. In summary, the reported data indicate that UEI may allow tissue engineers to sequentially evaluate the progress of tissue construct mechanical behavior in vivo and in some cases may reduce the need for interim time point animal sacrifice.

Placement of an elastic biodegradable cardiac patch on a subacute infarcted heart leads to cellularization with early developmental cardiomyocyte characteristics

BACKGROUND

Placement of an elastic biodegradable patch onto a subacute myocardial infarct (MI) provides temporary elastic support that may act to effectively alter adverse left ventricular (LV) remodeling processes.

METHODS

Two weeks after permanent left coronary ligation in Lewis rats, the infarcted anterior wall was covered with polyester urethane urea (MI + PEUU; n = 15) or expanded polytetrafluoroethylene (MI + ePTFE; n = 15) patches, or had no implantation (MI + sham; n = 12). Eight weeks after surgery, cardiac function and histology were assessed.

RESULTS

The ventricular wall in the MI + ePTFE and MI + sham groups was composed of fibrous tissue, whereas PEUU implantation induced α-smooth muscle actin-positive muscle bundles coexpressing sarcomeric α-actinin and cardiac-specific troponin-T. This pattern of colocalization was also found in developing embryonic myocardium. Cardiac transcription factors Nkx-2.5 and GATA-4 were strongly expressed in the muscle bundles. In the MI + sham group, end-diastolic LV cavity area (EDA) increased and the percentage of fractional area change (%FAC) decreased. For ePTFE patched animals, both EDA and %FAC decreased. In contrast, with MI + PEUU patching, %FAC increased and EDA was maintained. With dobutamine-stress echocardiography, MI + PEUU patched LVs possessed contractile reserve significantly larger than the MI + sham group.

CONCLUSIONS

MI + PEUU patch implantation onto subacute infarcted myocardium induced muscle cellularization with characteristics of early developmental cardiomyocytes as well as providing a functional reserve.

An elastomeric patch electrospun from a blended solution of dermal extracellular matrix and biodegradable polyurethane for rat abdominal wall repair

A biodegradable elastomeric scaffold was created by electrospinning a mixed solution of poly(ester urethane)urea (PEUU) and porcine dermal extracellular matrix (dECM) digest, with PEUU included to provide elasticity, flexibility, and mechanical support and dECM used to enhance bioactivity and biocompatibility. Micrographs and differential scanning calorimetry demonstrated partial miscibility between PEUU and dECM. With greater dECM content, scaffolds were found to possess lower breaking strains and suture retention strength, although initial modulus was greater with higher dECM concentrations. The hybrid scaffolds containing 0% to 50% dECM had tensile strengths of 5 to 7 MPa, breaking strains of 138% to 611%, initial moduli of 3 to 11 Mpa, and suture retention strengths of 35 to 59 MPa. When hydrated, scaffolds were found to contract markedly with 50% dECM content. When used in a rat full-thickness abdominal wall replacement model, no herniation, infection, or tissue adhesion was observed after 4 and 8 weeks with a scaffold containing 25% dECM or a control 100% PEUU scaffold. Scaffolds incorporating dECM were significantly thicker at the time of explant, with greater numbers of associated smooth muscle actin-positive staining cells than in the control, but minimal cellular infiltration and remodeling of the scaffold were detected regardless of dECM addition. The processing of dECM and PEUU from a mixed solution thus provided a scaffold with evidence of better bioactivity and with mechanical properties not achievable with digested dECM alone.

Mechanical properties and in vivo behavior of a biodegradable synthetic polymer microfiber-extracellular matrix hydrogel biohybrid scaffold

A biohybrid composite consisting of extracellular matrix (ECM) gel from porcine dermal tissue and biodegradable elastomeric fibers was generated and evaluated for soft tissue applications. ECM gel possesses attractive biocompatibility and bioactivity with weak mechanical properties and rapid degradation, while electrospun biodegradable poly(ester urethane)urea (PEUU) has good mechanical properties but limited cellular infiltration and tissue integration. A concurrent gel electrospray/polymer electrospinning method was employed to create ECM gel/PEUU fiber composites with attractive mechanical properties, including high flexibility and strength. Electron microscopy revealed a structure of interconnected fibrous layers embedded in ECM gel. Tensile mechanical properties could be tuned by altering the PEUU/ECM weight ratio. Scaffold tensile strengths for PEUU/ECM ratios of 67/33, 72/28 and 80/20 ranged from 80 to 187 kPa in the longitudinal axis (parallel to the collecting mandrel axis) and 41-91 kPa in the circumferential axis with 645-938% breaking strains. The 72/28 biohybrid composite and a control scaffold generated from electrospun PEUU alone were implanted into Lewis rats, replacing a full-thickness abdominal wall defect. At 4 wk, no infection or herniation was found at the implant site. Histological staining showed extensive cellular infiltration into the biohybrid scaffold with the newly developed tissue well integrated with the native periphery, while minimal cellular ingress into the electrospun PEUU scaffold was observed. Mechanical testing of explanted constructs showed evidence of substantial remodeling, with composite scaffolds adopting properties more comparable to the native abdominal wall. The described elastic biohybrid material imparts features of ECM gel bioactivity with PEUU strength and handling to provide a promising composite biomaterial for soft tissue repair and replacement.

Management of postpneumonectomy empyema using free flap and pedicled flap

Treatment of empyema after pneumonectomy is challenging. We treated 4 patients with postpneumonectomy empyema using a free rectus abdominis myocutaneous flap together with a pedicled pectoralis major muscle flap. The pectoralis major flap was used to fill the apical portion of the cavity, while the rectus abdominis flap was used to fill the caudal portion and occlude any bronchial fistula present. All empyemas were treated successfully without recurrence. This method has the advantage of filling apical and caudal parts of the space at once, making effective use of the combined volume of the two flaps.

Differences in blood flow volume and vascular resistance between free flaps: assessment in 58 cases

In free-flap transfer, blood flow in the transferred flap contributes to wound healing and to resistance against infection in the recipient site. Successful reconstructions using free tissue transfers may be required to define and choose flaps with abundant blood flow in necessary cases. We investigated blood flow in the flap by transit-time ultrasound flowmeter in 58 free-flap transfers. Flow volume was compared between flap tissues as vascular resistance in the flap was calculated. Fasciocutaneous and osteocutaneous flaps had relatively low blood flow volume, myocutaneous flaps had more, and intraperitoneal flaps had still higher blood flow volume. These differences were statistically significant. Vascular resistance significantly decreased in the same order of comparison. Our findings will help in selecting the most suitable flaps for reconstructive surgery.

Analysis of 13 cases with gastroepiploic vessels used as grafts

Free flaps are used increasingly in reconstructive surgery. However, many patients lack a satisfactory recipient vessel near the defect because of radiotherapy, post-traumatic infection, or treatment for recurrent tumor. We usually use a venous graft in such cases, but when both long arterial and venous segments are needed, we use the gastroepiploic vessels because they include extensive, viable arterial and venous segments. Between 1998 and 2006, we used gastroepiploic vessels as grafts in the 13 cases analyzed here. All defects lacked satisfactory recipient vessels nearby. Patients included 10 men and 3 women; mean age was 51.2 years (range, 14 to 82 years). Demographic and clinical background, results, and complications were analyzed retrospectively. Mean length of gastroepiploic vessels was 13.3 cm (range, 10 to 17 cm). All outcomes were satisfactory. A complication, abdominal wound infection secondary to harvesting of the gastroepiploic vessels, occurred in one case. Although the number of gastroepiploic vessels used as grafts analyzed here is relatively small, this experience confirms their clinical usefulness.

Effects of lowering barometric pressure on guarding behavior, heart rate and blood pressure in a rat model of neuropathic pain

We investigated whether lowering barometric pressure by 20 mmHg (LP) aggravates the guarding behavior suggestive of spontaneous pain following sciatic nerve chronic constriction injury (CCI) in rats. Systemic blood pressure (BP) and heart rate (HR) of unrestrained rats were recorded telemetrically during LP both before and after the CCI surgery. CCI rats showed guarding posture in normopressure conditions, and LP increased the cumulative time of this behavior. Baseline BP but not HR was increased following CCI. LP increased BP and HR of the rats only before the CCI surgery. Animals after CCI surgery showed variable (BP, HR) and transient (HR) responses to LP. These results indicate that (1) LP aggravated spontaneous pain and increased BP and HR in the CCI rats, and (2) CCI surgery influenced BP and HR of rats.

Effects of lowering ambient temperature on pain-related behaviors in a rat model of neuropathic pain

To clarify the mechanism by which changes in chronic pain are induced by cold environments, rats rendered neuropathic by a chronic constriction injury (CCI) to the sciatic nerve were exposed to low ambient temperature (LT; 7 degrees C decrease from 22 degrees C) in a climate-controlled room. LT exposure aggravated pain-related behaviors in CCI rats, i.e., decreased the threshold to von Frey hair and paw pressure stimulation, prolonged the duration of foot withdrawal to pinprick stimulation, and increased the cumulative duration of guarding posture. Lumbar sympathectomy (SYX) did not inhibit LT-induced augmentations of pain-related behaviors in CCI rats. LT exposure decreased the skin temperatures of both hind paws to the same degree in the sham-operated control and SYX rats, while in the CCI and SYX+CCI rats it caused a larger temperature decrease in the injured paw than in the uninjured one. These results indicate that LT exposure augments abnormalities in pain-related behaviors of neuropathic rats, and also suggest that sympathetic nervous activity is not a predominant factor in the augmenting mechanism.