Yusuke Hamamoto

Optimal technique for microvascular anastomosis of very small vessels: Comparative study of three techniques in a rat superficial inferior epigastric arterial flap model

OBJECTIVE The anastomosis of very small vessels (external diameter: < or = 0.5mm) is challenging and requires high microsurgical skill. This study aims to investigate the optimal technique for the anastomosis of very small vessels. We compared three anastomotic techniques on the basis of success rate and anastomosis time in a superficial inferior epigastric arterial flap model in rats. METHODS Forty-five Sprague-Dawley rats were divided into three groups of 15 rats. The superficial inferior epigastric artery flap was elevated, and only the artery was cut and anastomosed under magnification. The anastomosis was performed with the conventional technique, with the intravascular stenting technique or with the open guide suture technique. Flap survival was assessed on postoperative day 5, and the success rates of the groups were compared. In addition, the time required for anastomosis was compared between the groups. RESULTS All flaps survived, and success rates did not differ significantly between the groups. The average anastomosis times with the conventional technique (770.0s) and the intravascular stenting technique (822.8s) did not differ significantly but were significantly greater than that with the open guide suture technique (699.2s). CONCLUSION The open guide suture technique simplifies anastomosis and can be recommended as a new standard technique for the anastomosis of very small vessels. Furthermore, the benefit of the intravascular stenting technique is minimal for either skilled or unskilled microsurgeons.

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.

Scoring of Deformed Costal Cartilages Reduces Postoperative Pain after Nuss Procedure for Pectus Excavatum

OBJECTIVE The present study aims to elucidate whether or not scoring deformed cartilages reduces postoperative pain after the Nuss procedure for pectus excavatum patients. METHODS A total of 46 pectus excavatum patients for whom the Nuss procedure was conducted were included in the study. The patients were categorized into two groups, depending on whether or not the supplementary maneuver of scoring deformed cartilages was performed in addition to the Nuss procedure. Patients for whom deformed costal cartilages were scored were categorized as the Scoring Group (n = 24); those who received no such scoring were categorized as the Non-Scoring Group (n = 22). After evaluating the maximum stresses occurring on the thoraces by means of dynamic simulation using finite element analyses, intergroup comparison of the maximum von-Mises stress values was performed. Furthermore, after quantifying postoperative pain as the frequency with which patients injected anesthetics through an epidural pain-control system within 2 postoperative days, the degree of pain was compared between the two groups. RESULTS The maximum stresses occurring on the thorax were significantly greater for the Non-Scoring Group than for the Scoring Group; injection frequency was also greater for the Non-Scoring Group (average 4.9 times for 2 days) than for the Scoring Group (average 2.5 times for 2 days). CONCLUSION High stresses occur due to the performance of the Nuss procedure, causing postoperative pain. The stresses can be reduced by performing supplementary scoring on deformed cartilages. Accordingly, postoperative pain is reduced.

Rubinstein-Taybi syndrome (RTS) with postaxial polydactyly of the foot: 4-year follow-up until improvement of dysbasia

ABSTRACT  Rubinstein‐Taybi syndrome (RTS), also known as ‘broad thumbs syndrome’ or ‘broad thumb‐hallux syndrome’, is a malformation syndrome characterized by the triad of broad thumbs or first toes, a peculiar facial expression called ‘comical face’ and mental retardation. Although various malformations are combined with the triad, polydactyly is rare. We treated a male patient with RTS complicated by postaxial polydactyly of the foot. His clinical course was different from typical patients with polydactyly, especially in the aspect of walking development. Osteoplasty‐combined surgery, which was ideal for anatomical reconstruction, was performed on the patient at 2 years and 11 months of age. A 4‐year follow‐up period was required until there was an improvement of dysbasia.

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.

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

Abstract 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.

Mammary hypoplasia resulting from hormone receptor deficiency.

An 18-year-old female nursing student had bilateral mammary hypoplasia without remarkable history or family history. She had been healthy since birth, had menarche at the age of 13 years, and developed pubes normally. However, her breasts did not grow. At the age of 16 years, estrogen therapy was administered for 6 months at the pediatric department, but no response was observed. She could not wear brassieres even at the age of 18 years and was referred to our department. She was 151 cm tall and weighed 42 kg. The results of routine blood examination, blood cell counts, and physical findings were normal. She was normal and healthy in appearance, except for the breasts. The external genitalia were normal, and the vagina, uterus, and ovaries showed normal growth. The chromosomes were normal (46XX), and the menstrual cycle was 28 days. Hormone secretion was also normal (luteinizing hormone, 7.0 mIU/ml; follicle-stimulating hormone, 5.6 mIU/ml; estrogen 2, 14 to 35 pg/ml; estrogen 3, 10 ng/ml; progesterone, 0.5 ng/ml; prolactin, 3.1 ng/ml; thyrotropin, 0.82 IU/ml; triiodothyronine, 0.96 ng/ ml; and thyroxine, 9.0 g/dl). In the thorax, the pectoralis major muscle was normally palpated, but there were no mammary elevations (Fig. 1, above). There were bilateral areolae and adequately protruded nipples, but the diameters of the bilateral areolae and nipples were rather short (25 and 10 mm, respectively). Biopsy of the mammary gland was performed in the secretion phase of the menstrual cycle, and examination of hormone receptors (ER-EIA and PR-EIA; Abbott Laboratories, Abbott Park, Ill.)1 showed negative results (estrogen receptors and progesterone receptors 5.0 fmol/mg protein each). Surgery was performed under general anesthesia. A small

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.

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.

Segmental marking: A new technique to prevent pedicle twisting

1. Yamamoto T, Narushima M, Kikuchi K, et al. Lambda-shaped anastomosis with intravascular stenting method for safe and effective lymphaticovenular anastomosis. Plast Reconstr Surg 2011;127(5):1987e92. 2. Yamamoto T, Narushima M, Yoshimatsu H, et al. Minimally invasive lymphatic supermicrosurgery (MILS): indocyanine green lymphography-guided simultaneous multi-site lymphaticovenular anastomoses via millimeter skin incisions. Ann Plast Surg 2014;72(1):67e70. 3. Yamamoto T, Yamamoto N, Azuma S, et al. Near-infrared illumination system-integrated microscope for supermicrosurgical lymphaticovenular anastomosis.Microsurgery 2014;34(1):23e7. 4. Yamamoto T, Narushima M, Doi K, et al. Characteristic indocyanine green lymphography findings in lower extremity lymphedema: the generation of a novel lymphedema severity staging system using dermal backflow patterns. Plast Reconstr Surg 2011;127(5):1979e86. 5. Yamamoto T, Yoshimatsu H, Koshima I. Navigation lymphatic supermicrosurgery for iatrogenic lymphorrhea: supermicrosurgical lymphaticolymphatic anastomosis and lymphaticovenular anastomosis under indocyanine green lymphography navigation. J Plast Reconstr Aesthet Surg 2014;67(11):1573e9 [epub ahead of print].