Presence of manubrium-sternum joint does not assure sufficient elevation of sternum in Nuss procedure for pectus excavatum patients.

BACKGROUND: The manubrium and body of the sternum are connected by the manubrium-sternum joint (MSJ). In performing the Nuss procedure for pectus excavatum patients, the body of the sternum is elevated as the operator flips correction bars upside down. Theoretically, the presence of the MSJ should allow elevation of the sternum body. However, does the MSJ secure sufficient elevation of the sternum? This study aims to elucidate this clinical question. METHODS: Seventy-four adult pectus excavatum patients with moderate to serious deformity (with Haller Index being equal to or greater than 5) were included in the study. The MSJ was open in all patients. For 29 patients, the sternum was elevated by only bar flipping (Non-Separation Group); for 45 patients, the sternum was horizontally separated after bar flipping (Separation Group). Whether or not additional elevation for Separation Group patients results from the division was observed, and the degree of the additional elevation was evaluated. Furthermore, 74 patients subjectively evaluated postoperative pain and gave scores with a Visual Analog Scale ranging from 0 (no pain) to 10 (intolerable pain). The VAS scores were compared between the two groups. RESULTS: In the Separation Group, the sternums of all patients achieved additional elevation from sternum separation. The pain scores were lower for the Separation Group than for the Non-Separation Group. CONCLUSION: Even when the MSJ is present, horizontal separation enhances the elevation of the sternum. Furthermore, horizontal separation of the sternum reduces postoperative pain.

Biomechanical Evaluation of Additional Surgical Maneuvers to Improve Symmetry in Performing Nuss Procedure for Asymmetric Pectus Excavatum.

Background: Severing part of the thorax prior to bar placement is effective to improve outcomes in performing the Nuss procedure for asymmetric pectus excavatum. This study aims to elucidate the patterns of severing to provide an ideal outcome. Methods: Three-dimensional biomechanical computer models were produced simulating the thoraxes of 10 actual patients with asymmetric pectus excavatum. Virtual surgical operation was performed on the 10 models in 4 patterns: group 1-no part of the thorax was severed (default group). Group 2-The sternum was severed (sternum-severing group). Group 3-The ribs on the affected side were severed (rib-severing group). Group 4-Both the sternum and ribs on the affected side were severed (sternum/rib-severing group). After performing this preparation, simulation of bar placement was performed. Comparing the pre- and postoperative shapes of the models, we examined whether symmetry improved for each group. Results: Symmetry of the chest wall improved for rib-severing group and sternum/rib-severing group. Asymmetry remained for default group and sternum-severing group. Conclusions: Performance of the Nuss procedure for asymmetric pectus excavatum does not greatly improve symmetry of the chest wall. Severing the ribs as an additional maneuver is effective to improve symmetry.

Separation of the seventh costal-sternal junction-A new technique to improve outcomes for the Nuss procedure for pectus excavatum.

BACKGROUND: In the standard Nuss procedure for pectus excavatum, the costal arch is often elevated together with the sternum, resulting in unevenness of the lower part of the thorax. This complication is commonly called rib flaring. This paper presents a technique to avoid rib flaring and evaluates its effectiveness. MATERIALS AND METHODS: In our technique, a part of the seventh costal cartilage is removed, disconnecting the costal arch from the sternum. The effectiveness of this technique was evaluated in a retrospective clinical study of 63 pectus excavatum patients who were randomly collected and were divided into two groups. One group-defined as the Standard Group-includes 27 patients (29.8 ± 6.5SD y/o) on whom standard Nuss procedure was conducted; the other group-defined as the Separation Group-includes 36 patients (31.8 ± 6.1SD y/o) on whom the cartilage removal was conducted in addition to the standard Nuss procedure. The degree of postoperative costal-arch elevation was defined as ECA (Elevation of Costal Arch) and was compared between the two groups. RESULTS: ECA was significantly greater for the Standard Group (10.2 ± 3.3SD mm) than for the Separation Group (-1.1 ± 3.42SDmm). CONCLUSION: Postoperative protrusion of the costal arch is prevented by the separation of the seventh costal cartilage from the sternum. Our original technique is a useful option for the treatment of pectus excavatum.

How Partial Skull Defect Affects Vulnerability of the Skull in Traumatic Situations: A Biomechanical Study.

Background: Part of the skull can be lost due to neurosurgical diseases or trauma. Skulls with partial defects can develop different fracture patterns from those of intact skulls. This study aims to clarify the differences. Methods: A 3-dimensional skull model was produced by referring to the computer-tomography data of a 23-year-old intact male volunteer. We defined the model as Intact Model. Another model was produced by removing part of the frontal bone, which was defined as Defect Model. Dynamic simulations of impacts were performed varying the site and direction of impact. Fracture patterns caused by the impacts were calculated using dynamic analysis software (LS-DYNA; Livermore Software Technology Corp.) and were compared between the intact model and defect model. Results: When Defect Model was impacted, fracture involved wider areas than when Intact Model was impacted. This finding was observed not only when Defect Model was impacted on its defect side but also when it was impacted on its intact side. Conclusions: When a skull carrying a defect on one side is impacted, serious fracture occurs even when the non-defect side is impacted, meaning that a skull with a defect is vulnerable to impacts on the non-defect side. This finding should be taken into consideration in deciding indications of skull defect reconstruction.

Hardness of Artificial Bone and Vulnerability of Reconstructed Skull-A Biomechanical Study.

Background: Various materials are used to reconstruct cranial defects. The present study focuses on what happens when reconstructed skulls are impacted in trauma situations. Using biomechanical analysis, the present study elucidates how the hardness of reconstruction material affects the vulnerability of reconstructed skulls. Methods: A 3-dimensional finite element model was produced simulating the skull of an intact adult male. A defect was made on the left hemi-frontal part of the skull model. The defect was restored with artificial bone with 3 different hardness models. These models were respectively defined as Hard Model (simulating reconstruction with titanium), Moderate Model (simulating reconstruction with a material equivalent to human bone), and Soft Model (simulating reconstruction with hydroxyl apatite). Virtual impacts were applied on these models in 9 patterns, and the conditions of subsequent fracture were evaluated using finite element analysis. For each of the 9 impact patterns, the conditions of subsequent fracture were compared among the 3 models. Results: In 8 of the 9 impact patterns, the condition of fracture was more widespread for Hard Model than for Moderate Model and Soft Model. Conclusions: Skulls reconstructed with a hard material can develop serious fracture if they are impacted again. Therefore, usage of hard materials should be avoided to prevent serious injuries from secondary trauma.

Outcomes of the Nuss procedure for pectus excavatum in adults.

Limited data exist with regard to the outcome of the Nuss procedure for pectus excavatum repair in adults. Here, we analysed changes in lung capacity and thoracic morphology based on computed tomography (CT) imaging in adults with pectus excavatum before surgery, during bar insertion and after bar removal. Patients who underwent the Nuss procedure for pectus excavatum after the age of 20 were included in this study. Chest CT scans of the included participants were taken before the Nuss procedure, immediately before removal of the pectus bar and 6 months after removal of the pectus bar. Lung capacity and thoracic morphology measurements were made from the CT scans. Six patients aged 24-43 years were included in this study. After the Nuss procedure, lung capacity was decreased in all patients. Although the pectus bar was removed, lung capacity had not significantly increased and was almost the same volume as before the Nuss procedure. After the Nuss procedure, the funnel chest shape had improved in all cases, patients' thoracic spine had also moved forward as the thorax moved forward and patients' stoop had improved. Despite a lack of change in lung capacity, surgical modification should be considered to reduce stress on the thoracic spine and in turn, reduce pain in patients with pectus excavatum. However, further long-term observation seems necessary.

Spontaneously generated large adipose flaps in vivo tissue engineering chambers.

AIM: Previous experiments using our in vivo tissue engineering chamber (TEC) model demonstrated that adipose flap was spontaneously generated without the need for adipocyte or stem cell implantation. The purposes of the present study are to clarify 1) the reproducibility of this method to create adipose flaps, 2) the time-course of adipogenesis, and 3) the long-term stability of the adipose flap generated. METHODS: The chambers that afforded a protected space for tissue growth were implanted into the groins of rabbits. A vascular pedicle as the vascular source of newly formed tissue, a collagen sponge as a scaffold, and platelet-rich plasma (PRP) and fibroblast growth factor (bFGF) as growth factors were contained within the chamber. There were three experimental groups according to the implantation period of the chamber; Group 4 w, Group 8 w, and Group 12 w (n = 5 in each group). RESULTS: The percent volumes of the combined adipose/pedicle tissue compared with the total volume of the generated tissue were 14.8% (0.437 cm3/2.96 cm3), 47% (0.87 cm3/1.85 cm3) and 80% (1.82 cm3/2.27 cm3) in Groups 4 w, 8 w, and 12 w, respectively. When a 12-week adipose flap was transferred outside the chamber on its vascular pedicle and retained for a further five months, it became more like mature adipose tissue and had increased fat density. CONCLUSION: Adipose flaps were spontaneously generated in vivo in TECs at 12 weeks with reproducibility and showed long-term stability outside the chamber following pedicle transfer. The tissue-engineered adipose flap will contribute to breast reconstruction and augmentation without donor-site morbidity.

Fusuma Sliding Flap for Lip Reconstruction of Lower Lip Cancer.

Lower lip cancer is typically treated with surgical excision, and this frequently results in a large defect and severe aesthetic problems. Local flap reconstruction is suitable for restoring appearance and function, and it causes less surgical stress than a vascularized free flap. The Fusuma sliding flap is a local flap technique introduced by Kasai et al in 2008. Here, the authors report their use of this method for lip reconstruction in a 94-year-old Japanese female after the removal of a cancerous mass.

Bone-cartilage proportion in deformed ribs of male pectus excavatum patients.

This study verifies the hypothesis that bone/cartilage proportion in deformed ribs of male pectus excavatum patients varies according to their ages. Anatomical evaluation of the thoraces was performed for 79 male pectus excavatum patients, referring to their three-dimensional computer-tomographic images. The patients were divided into Child Group (5-9 years old: n = 35); Adolescent Group (12-15 years old: n = 15) and Adult Group (18+ years old: n = 29). For each patient, the most concave point of the sternum was identified and the pair of ribs closest to the point were defined as Key Ribs. On each Key Rib, the most ventral point was defined as Prominent Point (PP); the junction between the bone and cartilage was defined as Costo-Chondral Junction (CCJ). The distances of these points from the spine were defined as Distance of Prominent Point (DPP) and Distance of Costo-Chondral Junction (DCCJ), respectively. The horizontal length of the Key Rib was defined as Rib Length (RL). Inter- and intra-group comparisons were performed for DPP/RL and DCCJ/RL. Inter-Group Comparison: DCCJ/RL is significantly smaller and DPP/RL is significantly greater in Adult Group than in Child Group, meaning CCJs shift medially and PPs shift laterally as patients get older. Intra-Group Comparison: In Child Group, DCCJ/RL is significantly greater than DPP/RL, meaning CCJs exist lateral to PPs. Contrarily, in Adult Group, DCCJ/RL is significantly smaller than DPP/RL, meaning CCJs exists medial to PPs. Bone/cartilage proportion in the concave part of the chest shifts according to patients' ages. To perform the Nuss procedure effectively, this age-related anatomical change must be taken into consideration.

Frontal Bone Fracture Patterns Suggesting Involvement of Optic Canal Damage.

PURPOSE: Fracture of the frontal bone can be accompanied by damage to the optic canal. The present study uses finite element analysis to identify fracture patterns, suggesting the involvement of the optic canal. METHODS: Ten finite-element skull models were generated from computer tomography data of 10 persons. Then, dynamic analyses simulating collision of a 2-cm-radius brass ball to 6 regions on the frontal bone in the 10 models were performed. Fracture patterns presented by the frontal bone in the 60 experiments were observed, and all those involving the optic canal were selected. Commonalities of the selected fracture patterns were identified. RESULTS: Fracture of the optic canal was observed in 9 of the 60 patients. In all 9 patients, fracture existed on the anterior and posterior walls of the frontal sinus and on the superior orbital wall. CONCLUSION: When the anterior and posterior walls of the frontal sinus and the superior orbital wall are all broken, the optic canal is highly likely to be involved in the damage. When this pattern is observed in emergency examination, preventive decompression of the optic nerve should be considered to avoid potential occurrence of blindness.

Biomechanical analysis of likelihood of optic canal damage in peri-orbital fracture.

PURPOSE: Detection of optic canal fractures is often difficult because of the subtleness of the fracture. If we could clarify impact on which region around the orbit is likely to accompany the fracture of the optic canal, the knowledge should be useful to make early diagnosis of optic canal fractures. The present study was conducted to elucidate this issue. METHODS: Ten finite element models were produced simulating the skulls of ten humans (8 males and 2 females; 43.8 ± 10.2 y/o). The peri-orbital area of each of the ten models was divided into eight regions in a clockwise fashion per 45 degrees. These regions were defined as Superior-Medial (0-45 degrees), Medial-Superior (45-90 degrees), Medial-Inferior (90 to 135 degrees), Inferior-Medial (135 to 180 degrees), Inferior-Lateral (180-225 degrees), Lateral-Inferior (225 to 270 degrees), Lateral-Superior (270-315 degrees), and Superior-Lateral regions (315-360 degrees), respectively. Dynamic simulation of applying traumatic energy on each of these regions was conducted. Resultant fracture patterns were evaluated using finite element analyses. Thereafter, frequencies of fracture involvement of the optic canal were evaluated for each of the eight regions. RESULTS: The involvement of the optic canal was most frequent for the Superior-Medial region (7/10), followed by the Medial-Superior region (5/10). CONCLUSION: Optic canal fracture is likely to occur when the area between the supra-orbital notch and the medial canthus are strongly impacted. When evident fracture or serious damage of soft tissue is observed in this area, occurrence of optic canal fracture should be suspected.

Separation patterns of orbital wall and risk of optic canal injury in Le Fort 3 osteotomy.

PURPOSE: The authors hypothesized that the risks of optic canal injury in down-fracturing after Le Fort 3 osteotomy vary depending on the separation patterns of the orbital walls. This study verifies this hypothesis using biomechanical simulation. METHODS: Ten finite-element skull models were produced using computer tomography data from ten persons. These models were modified to simulate Le Fort 3 osteotomy models by removing junctions between the neurocranium and facial cranium. The separation of the orbital wall was performed in four differing ways. In Type 1, all walls were completely separated. In Type 2, only the lateral wall was separated. In Type 3, the inferior wall was left unseparated. In Type 4, the lateral wall was left unseparated. Biomechanical simulation of down-fracturing was performed on the resulting 40 models. By observing irregular fractures occurring inside the orbit, the rate of optic canal involvement was evaluated for each of the four orbital-wall separation patterns. RESULTS: The rates of optic canal involvement were: Type 1 (0/10), Type 2 (0/10), Type 3 (0/10), and Type 4 (4/10). CONCLUSION: When the lateral wall is incompletely separated in Le Fort 3 osteotomy, irregular fracture can develop inside the orbit and involve the optic canal during the down-fracturing process. Hence, the lateral orbital wall should be completely separated to avoid potential blindness due to optic canal injury.

Effects of platelet-rich plasma on tissue-engineered vascularized flaps in an in vivo chamber.

AIMS: We investigated the reproducibility of creating a vascularized tissue flap in an in vivo tissue engineering chamber by incubating a vascular pedicle imbedded in a collagen sponge with activated platelet-rich plasma (aPRP) and basic fibroblast growth factor (bFGF). METHODS: Collagen sponge soaked with saline (control group), bFGF (Group 1), aPRP (Group 2), and aPRP/controlled release bFGF (Group 3) was implanted with a saphenous arteriovenous pedicle into a tissue engineering chamber, located subcutaneously in the groin of rabbits. After 4 weeks of implantation, the contents in the chamber were harvested for volumetric and histological analyses. RESULTS: The total volume of generated tissue in Group 3 was the largest among the Groups (control group vs. Group 3, p < 0.01). The volume of the pedicle vascular bundle/adipose tissue component was larger in Groups 1 and 3 than that in the control group (p < 0.05 and p < 0.01, respectively). The inflammatory tissue volume was larger in Groups 2 and 3 (control group vs. Group 3, p < 0.05). In a smaller long-term study, inflammatory tissue at 4 weeks was gradually replaced by the adipose tissue within 8 weeks. CONCLUSION: PRP-induced inflammatory reactions were considered to be necessary to stimulate cell migration into the chamber, leading to more tissue regeneration with abundant cell components. We conclude that PRP contributes to the reproducibility of preparing vascularized flaps in an in vivo chamber.

Normobaric oxygen therapy increases cartilage survival ratio in auricular composite grafting in rat models.

PURPOSE: This study aims to clarify whether normobaric oxygen therapy improves the survival of auricular composite grafts in rats. METHODS: For 10 male SD rats, 1.5 cm2 composite grafts were harvested from bilateral ear regions including whole auricles. The harvested grafts were transferred caudally and sutured there. The 10 rats were randomly divided into two groups and kept for 21 days in two different circumstances. The first group (Control group: five rats carrying 10 grafts) was kept in room air (20% oxygen) throughout the 21 days, and the second group-named NBO (normobaric oxygen) group (five rats carrying 10 grafts)-was kept in normobaric 60% oxygen for 3 days and then in room air for 18 days. All the 10 rats were sacrificed on the 21st day. Surviving areas of the grafts and the height of the surviving auricular cartilage were examined for statistical comparison of the two groups. Furthermore, the conditions of chondrogenesis occurring around the perichondrium were compared between the two groups. RESULTS: Surviving areas did not present statistically significant differences between the two groups. The height of surviving cartilage was significantly greater for the NBO group (2610 ± 170 SD µm) than that for the Control group (1720 ± 190 SD µm). Chondrogenesis occurred at positions more distant from the recipient bed in the NBO group than that in the Control group. CONCLUSION: Normobaric oxygen therapy increases the thickness of surviving cartilage in auricular composite grafting in rats, thus suggesting that NBO therapy may also be effective in composite grafting for humans.

Distraction Osteogenesis for Brachymetatarsia by Using Internal Device.

Congenital brachymetatarsia most commonly involves the fourth ray and may be combined with metacarpal shortening. Now, many reports demonstrated the usefulness of distraction osteogenesis for lengthening of the metatarsals by using an external distraction device. In this article, we treated shortening fourth metatarsal by bone lengthening using the internal distraction device. This technique has some advantages over the method of external distraction.

Thoracic outlet syndrome after the Nuss procedure for pectus excavatum: Is it a rare complication?

OBJECTIVE: The present study aims to elucidate the frequency of thoracic outlet syndrome after the Nuss procedure for pectus excavatum and the conditions in which thoracic outlet syndrome is likely to develop. METHODS: A retrospective study including 85 pectus excavatum patients (58 males and 27 females) was conducted. Thoracic outlet syndrome was defined as a condition in which the patient has numbness, lassitude, or pain of the upper limbs at rest or during motion of the upper limbs. The frequency of the thus-defined thoracic outlet syndrome was evaluated in 85 patients. Age, sex, Haller indices, and the positions of the correction bars were compared between the patients who developed thoracic outlet syndrome and those who did not. RESULTS: Preadolescent patients (18 out of 85) did not develop postoperative thoracic outlet syndrome. In total, 15.2% of adult male patients (7 out of 46) and 33% of adult female patients (7 out of 21) developed postoperative thoracic outlet syndrome. For both male and female groups, Haller indices were significantly greater for patients who had postoperative thoracic outlet syndrome than for those who did not. Correction bars were generally placed at higher intercostal spaces in patients who developed postoperative thoracic outlet syndrome than in those who did not. CONCLUSION: A considerable percentage of adult patients develop thoracic outlet syndrome after the Nuss procedure for pectus excavatum. Maturity of the thoracic wall, femininity, severity of the deformity (represented by greater Haller indices), and placement of correction bars at superior intercostal spaces are risk factors for postoperative thoracic outlet syndrome.

An anatomical study on the availability of contralateral recipient vessels in hemi-mandibular reconstruction with vascularised free fibula transfer.

BACKGROUND: In mandibular reconstruction with vascularised free fibula transfer, there are situations where the neck on the operated site lacks recipient vessels for vascular anastomosis due to previous radiological/surgical interventions. METHODS: The present study aims to clarify the availability of neck vessels on the contralateral side in such situations. Experimental surgery was conducted on 20 fresh cadavers (six males and 14 females). After the left half of the mandible was removed, free vascularised fibula of equivalent length was transferred to fill the defect. The possibility of connecting the peroneal artery and vein to the superior thyroid artery (STA), transverse coli artery (TCA), internal jugular vein (IJV), and external jugular vein (EJV) of the contralateral side was evaluated. RESULTS: In all samples, the peroneal vessels could reach the STA and EJV. However, the peroneal vessels could reach the TCA and IJV of the contralateral side in only 45% and 64.2% of cases, respectively. The average and standard deviation of the lengths by which vessels were insufficient were 1.1 ± 13.9 mm for IJV and 8.8 ± 24.7 mm for TCA. CONCLUSIONS: In reference to these findings, it is concluded that, in situations where neck vessels of the defect side are unavailable, availability of the superior thyroid artery and external jugular vein should be examined first. When these vessels are available as recipient vessels, direct vascular anastomosis is highly likely to be successful. In cases where these vessels are unavailable and the transverse coli artery or internal jugular vein is used as the recipient, vascular interposition might be necessary.

Preservation of deep-layer fat of lateral zones prevents postoperative seroma after TRAM-flap harvesting for breast reconstruction: a retrospective study.

OBJECTIVE: The present study elucidates whether or not preserving fat tissues deeper than the Scarpa's fascia in zone 3 and zone 4 reduces postoperative fluid collection after harvesting the transverse rectus-abdominis muscle (TRAM) flap. METHODS: Thirty-one patients for whom breast reconstruction with free TRAM flaps had been performed were included in the study. Fat tissues deeper than the Scarpa's fascia in zone 3 and zone 4 were addressed in two ways. With 17 patients, these tissues were preserved on the abdominal wall; with 14 patients, these fat tissues were harvested as part of the TRAM flap. The former and latter groups were named the Preservation Group and Non-Preservation Group, respectively. Drainage tubes were placed at the donor site until daily drainage became less than 20 ml, at which time the tubes were removed. The total amount of postoperative fluid drained from the donor site and the days required before tube removal were compared between the two groups. RESULTS: The total volume of drained fluid was significantly greater for the Non-Preservation Group (444 ± 48.2 ml) than for the Preservation Group (230 ± 21.9 ml); the period before removal of drainage tubes was significantly longer for the Non-Preservation Group (12.4 ± 0.84 days) than for the Preservation Group (7.6 ± 0.55 days). CONCLUSION: Preservation of deep-fat tissues in zone 3 and zone 4 reduces postoperative fluid exuded from the donor site, and enables earlier removal of drainage tubes. For cases where optimal breast shape can be achieved without these fat tissues, the fat tissues should be preserved.

Utilization of a sero-muscular patch for safe wound closure after free jejunum transfer for a skin-esophageal fistula.

This paper introduces our original technique of free jejunum transfer, in which a sero-muscular patch is used to cover the jejunum. Our results demonstrate its effectiveness for touch-up surgery after esophageal leakage.