Geometric considerations in the design of rotation flaps in the scalp and forehead region

The classical transposition and rotation flaps are well known. Cosmetic considerations in the scalp and forehead region limit the use of a flap design that requires a skin graft for a donor defect. On sound geometric principles, the classical flap designs are suitably modified here to have a somewhat equal proportion of transposition and rotation. This "modified rotation flap" design works to a maximum advantage in the inextensible region of the scalp and forehead by providing single-stage primary closure of moderate to large defects. No backcuts are ever necessary with this flap design. Use of this principle to modify the rotation flap design for closure of an extended midline forehead defect following rhinoplasty allows a still wider (up to 6.5 cm) midline forehead flap to be available for rhinoplasty with primary closure of the donor defect.     

VY bipedicle flap for resurfacing the nasal supratip region

A procedure for the coverage of surgically created supratip defects up to 1.5 cm in diameter is described utilizing a VY bipedicle flap of nasal skin.     

The HIV-1 central DNA flap region contains a "flapping" third strand

Due to the discontinuous nature of HIV-1 plus-strand DNA synthesis, a 99-nt plus-strand overhang termed the "central DNA flap" is present near the center of the proviral DNA prior to integration. The flap appears to have stabilizing and/or protective effects on viral DNA, which has been hypothesized to be due to a specific conformation adopted by the three-stranded region. The 5' end of the flap sequence is very purine rich and has the potential to adopt different secondary structures (e.g., duplex, triplex or quadruplex). In the present work, circular dichroism spectroscopy and thermal unfolding techniques were used to characterize an 89-nt long DNA sequence designed to mimic the three-stranded region at the 5' end of HIV-1 proviral DNA. The effect of addition of the HIV-1 nucleocapsid protein (NC) on the nucleic acid structure was also examined. Although, guanine-rich short oligonucleotides derived from the DNA flap demonstrated CD spectra characteristic to parallel quadruplexes, this analysis reveals that the extended 89-nt construct folds into a canonical duplex with a "flapping" third strand both in the absence and presence of NC.     

Novel tool in rheumatoid arthritis diagnosis—The usage of urease flap region peptidomimetics

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease. Early diagnosis can prevent joint erosion. However, available biomarkers do not always allow for clear distinction between RA and non‐RA individuals. It has become known that bacteria/viruses are among the environmental triggers that initiate RA via multiple molecular mechanisms. Thus, to better understand the role of bacteria in RA, we synthetized 6 peptidomimetics of bacterial ureases' flap region. These peptides were then used to distinguish RA patients from healthy people sera by immunoblotting. Most patients' sera were bound to peptidomimetic characteristic for Enterobacter sp. and Klebsiella sp. flap urease. We also found similarities between peptidomimetic sequence and human proteins connected with RA. This pilot study suggests that bacteria may trigger RA via mechanism of molecular mimicry of urease to host proteins and ureases flap peptidomimetics may be potential candidate as a new additional diagnostic test.     

Use of submandibular flap to close pharyngostomes and other defects of lower anterior neck region.

We describe the use of a suprahyoid flap for reconstruction in the lower anterior neck. It has been most useful for immediately closing pharyngostomes and for resurfacing defects from the excision of squamous cell carcinoma of the larynx or other neoplasms involving the skin. This flap provides a good deal of viable tissue, it can easily be rotated without a delay procedure, and the donor area is closed by direct suture. We present our experience with 22 cases.     

A new version of the trapezius osteomyocutaneous flap for reconstruction of the lateral wall of the orbit and the malar region

The author reports a new variety of trapezius osteomyocutaneous flap that contains the medial border of the shoulder blade and the innermost quarter of the scapular spine. This flap was successfully applied in reconstruction of the lateral orbital wall and malar compound along with the surrounding soft parts.     

Studies on adaptability of binding residues and flap region of TMC-114 resistance HIV-1 protease mutants

Drug resistant mutations have severely restricted the success of HIV therapy. These mutations frequently involve the aspartic protease encoded by the virus. Knowledge of the molecular mechanisms underlying the conformational changes of HIV-1 protease mutants may be useful in developing more effective and longer lasting treatment regimes. The flap regions of the protease are the target of a particular type of mutations occurring far from the active site, which are able to produce significant resistance against the anti-HIV drug TMC-114. We provide insight into the molecular basis of TMC-114 resistance major flap mutations (I50V and I54M) in HIV-1 protease. It reports the shape complementarity and receptor-ligand interaction analysis supported by unrestrained all-atom molecular dynamics simulations of wild and major flap mutants of HIV-1 protease that sample large conformational changes of the flaps and active site binding residues. Both resistant flap mutants showed less atomic interaction toward TMC-114 and more structural deviation compared to wild HIV-protease. It is due to increasing flexibility at TMC-114 binding cavity and deviation of binding residues in 3-D space. Distortion in binding cavity and deviation in binding residues are the result of alteration in hydrogen bonding. Flap region also exhibited similar behaviour due to changes in number of hydrogen bonds during simulations.     

Repair of a huge defect of the gluteal region by rotation of a combined tensor fasciae latae-sartorius myocutaneous flap

Although the tensor fasciae latae myocutaneous flap is convenient for covering some defects in the gluteal region, it is not suitable to repair a huge defect because of its limited area. Based on the close relationship of the sartorius and the tensor fasciae latae at their origins and blood supply, the authors designed a myocutaneous flap containing both the tensor fasciae latae and the sartorius muscles and their skin territories with an area exceeding 800 cm2. Two successfully repaired patients are reported. The flaps provide normal sensitivity. The vascular pedicle has a reliable anatomy, being easily dissected, and averages 4.6 to 5.8 cm in length. Both muscles are expendable. There is little functional difficulty for hip joint after the operation.     

The exonucleolytic and endonucleolytic cleavage activities of human exonuclease 1 are stimulated by an interaction with the carboxyl-terminal region of the Werner syndrome protein

Exonuclease 1 (EXO-1), a member of the RAD2 family of nucleases, has recently been proposed to function in the genetic pathways of DNA recombination, repair, and replication which are important for genome integrity. Although the role of EXO-1 is not well understood, its 5' to 3'-exonuclease and flap endonuclease activities may cleave intermediates that arise during DNA metabolism. In this study, we provide evidence that the Werner syndrome protein (WRN) physically interacts with human EXO-1 and dramatically stimulates both the exonucleolytic and endonucleolytic incision functions of EXO-1. The functional interaction between WRN and EXO-1 is mediated by a protein domain of WRN which interacts with flap endonuclease 1 (FEN-1). Thus, the genomic instability observed in WRN-/- cells may be at least partially attributed to the lack of interactions between the WRN protein and human nucleases including EXO-1.     

Neurovascular free-muscle transfer for the treatment of established facial paralysis following ablative surgery in the parotid region

Neurovascular free-muscle transfer for facial reanimation was performed as a secondary reconstructive procedure for 45 patients with facial paralysis resulting from ablative surgery in the parotid region. This intervention differs from neurovascular free-muscle transfer for treatment of established facial paralysis resulting from conditions such as congenital dysfunction, unresolved Bell palsy, Hunt syndrome, or intracranial morbidity, with difficulties including selection of recipient vessels and nerves, and requirements for soft-tissue augmentation. This article describes the authors' operative procedure for neurovascular free-muscle transfer after ablative surgery in the parotid region. Gracilis muscle (n = 24) or latissimus dorsi muscle (n = 21) was used for transfer. With gracilis transfer, recipient vessels comprised the superficial temporal vessels in 12 patients and the facial vessels in 12. For latissimus dorsi transfer, recipient vessels comprised the facial vessels in 16 patients and the superior thyroid artery and superior thyroid or internal jugular vein in four. Facial vessels on the contralateral side were used with interpositional graft of radial vessels in the remaining patient with latissimus dorsi transfer. Cross-face nerve grafting was performed before muscle transfer in 22 patients undergoing gracilis transfer. In the remaining two gracilis patients, the ipsilateral facial nerve stump was used as the primary recipient nerve. Dermal fat flap overlying the gracilis muscle was used for cheek augmentation in one patient. In the other 23 patients, only the gracilis muscle was used. With latissimus dorsi transfer, the ipsilateral facial nerve stump was used as the recipient nerve in three patients, and a cross-face nerve graft was selected as the recipient nerve in six. The contralateral facial nerve was selected as the recipient nerve in 12 patients, and a thoracodorsal nerve from the latissimus dorsi muscle segment was crossed through the upper lip to the primary recipient branches. A soft-tissue flap was transferred simultaneously with the latissimus muscle segment in three patients. Contraction of grafted muscle was not observed in two patients with gracilis transfer and in three patients with latissimus dorsi transfer. In one patient with gracilis transfer and one patient with latissimus dorsi transfer, acquired muscle contraction was excessive, resulting in unnatural smile animation. The recipient nerves for both of these patients were the ipsilateral facial nerve stumps, which were dissected by opening the facial nerve canal in the mastoid process. From the standpoint of operative technique, the one-stage transfer for latissimus dorsi muscle appears superior. Namely, a combined soft-tissue flap can provide sufficient augmentation for depression of the parotid region following wide resection. A long vascular stalk of thoracodorsal vessels is also useful for anastomosis, with recipient vessels available after extensive ablation and neck dissection.     

Total ear reconstruction in the devascularized temporoparietal region: II. Use of the omental free flap

Total ear reconstruction using the omental free flap technique was performed on five patients who presented with a devascularized temporoparietal region. The main indication for this technique was unavailability of the contralateral temporoparietal fascia in those requesting autogenous auricular reconstruction. There were no microvascular failures in the procedures conducted. In one case there was a partial loss of the transferred omentum, which resulted from an inadequate omental tailoring. A normal convoluted auricle was obtained after multistage debulking operations and meticulous postoperative molding. The average follow-up period was 3.4 years. Final aesthetic results were graded as satisfactory in four patients and poor in one patient.     

The lateral intercostal neurovascular free flap

The lateral intercostal flap is a new neurovascular flap that may be used as a free or island flap. It is based on the lateral cutaneous branch of a single posterior intercostal neurovascular bundle. The donor area of the flap is the anterolateral skin of the abdomen. The flap is large, thin, and has a long pedicle that contains the lateral cutaneous nerve. The donor pedicles of the flap are multiple, and its venous drainage is adequate. The detection and design of this flap were based on information gained from the dissection of 95 intercostal spaces in 40 fresh cadavers. The flap was then applied 12 times in 11 patients. Ten flaps were successful, one flap was partially lost, and one was completely lost. The flap was used as a noninnervated flap to resurface six defects in the neck and one facial defect, and it was used as an innervated flap to cover two hand defects and two heel defects.     

Monitoring flap for buried free tissue transfer: its importance and reliability

To improve the success rate of microsurgical flap transfers into a buried area, it is important to monitor the circulation of the flap during the early stage. A monitoring flap includes such advantages as simplicity, reliability, noninvasiveness, and the ability to continuously monitor the vascular status of various buried flaps. This article describes experiences related to the importance and reliability of a monitoring flap. A total of 109 flaps in 99 patients were treated with buried free flaps, including a monitoring flap, between 1990 and 1999. Forty-nine patients received a tubed free radial forearm flap with a skin-monitoring flap, and six received a free jejunal flap with a jejunal segment monitoring flap for the reconstruction of the esophagus. Vascularized fibular grafts with a skin monitoring flap or peroneus longus muscle monitoring flap were used for reconstructing the mandible in six patients and for treating osteonecrosis of the femoral head in 48 flaps in 38 patients. Monitoring flap abnormalities were indicated in 14 flaps; therefore, immediate revisions were performed on the pedicle of the monitoring flap and microanastomosis site. Among these 14 flaps, nine showed true thrombosis and five showed false-positive thrombosis. Among the nine flaps that showed true thrombosis, five were salvaged and four were finally lost. The false-positive thrombosis in the five flaps was attributed to torsion or tension of the perforator of the monitoring flap in three flaps, an unclear determination in one flap because the monitoring flap size was too small, and damage to the perforator in the last flap. The total thrombosis rate was 8.3 percent (nine of 109), and the failure rate of the free tissue transfer was 3.7 percent (four of 109). The overall sensitivity of the monitoring flap was 100 percent, the predictive value of a positive test was 64 percent (nine of 14), and false-positive results occurred in 36 percent (five of 14). The salvage rate was 55.6 percent. To improve the reliability of a monitoring flap, it is recommended that the size of the flap be larger than 1 x 2 cm to assess the arterial status, and that a perforator with the appropriate caliber be selected. When a monitoring flap is fixed to a previous incision line or a newly created wound, any torsion or tension of the perforator should be avoided. In conclusion, the current results suggest that a monitoring flap is a simple, extremely useful, and reliable method for assessing the vascular status of a buried free flap.     

Two options for perforator flaps in the flank donor site: latissimus dorsi and thoracodorsal perforator flaps

Two types of perforators, septocutaneous and musculocutaneous, are found in the same donor site of the flank area, and two perforator flaps based on each perforator are clinically available. Therefore, it is necessary to distinguish them from one another using different nomenclatures. Accordingly, the perforator flap based on a musculocutaneous perforator is named according to the name of the muscle perforated, the latissimus dorsi perforator flap, and the perforator flap based on a septocutaneous perforator, located between the serratus anterior and latissimus dorsi muscles, is named according to the name of the proximal vessel, the thoracodorsal perforator flap. In this series of 42 latissimus dorsi perforator flaps, flap size ranged from 5 x 3 cm to 20 x 15 cm, and two complications were observed: a marginal necrosis in an extremely large flap (26 x 12 cm) and a failure caused by infection. The thoracodorsal perforator flap was used in 14 cases, including two cases of chimeric composition. Flap size ranged from 4.5 x 3.5 to 18 x 15 cm, with no complications. In the two patterns of perforator flap that the author used, initial temporary flap congestion was observed in five latissimus dorsi perforator flap cases and two thoracodorsal perforator flap cases, when the flap was designed as a large flap or a less reliable perforator was selected. However, the congestion was not serious enough to cause flap necrosis. Several techniques, such as T anastomosis or inclusion of an additional perforator or a small portion of muscle, are recommended to prevent the initial flap congestion, especially when an unreliable perforator is inevitably used or when a flap larger than 20 cm long is required. A small portion of the muscle was included in six cases, when an unduly large or improperly long flap was planned. All of the flaps were successful and ranged from 22 x 7 to 15 x 28 cm, except for one case of distal flap necrosis in an extraordinarily large flap measuring 34 x 10 cm. Diverse selection of the perforator flap is one of the great advantages of the flank donor site, providing it with wider availability and more versatile composition for reconstruction or resurfacing.     

Comparison of the effect of bacterial inoculation in musculocutaneous and fasciocutaneous flaps

The skin fascial flap is now recognized as a reliable flap for use in reconstructive surgery. The fasciocutaneous flap has been advocated for coverage of chronic infected wounds after debridement as an alternative to the musculocutaneous flap. Previous experimental and clinical studies have demonstrated the superior resistance of the musculocutaneous flap as compared to the random-pattern flap to bacterial inoculation. A canine model is presented for comparison of the effect of bacterial inoculation in fasciocutaneous and musculocutaneous flaps of similar dimensions. The area of skin necrosis secondary to bacterial inoculation was similar in these two flap types despite greater blood flow and skin oxygen in the fasciocutaneous flap. In a study of closed wound spaces formed by the deep surface of these two flap types, a greater degree of inhibition and elimination of bacterial growth and more collagen deposition are observed in the musculocutaneous wound space than in the fasciocutaneous flap.     

A newly defined conchal floor arterial flap for auricular reconstruction

A conchal floor composite flap pedicled by skin of the helical crus has been well described in the literature. Here the flap is elevated based on the supply by an upper auricular branch of the superficial temporal artery. In this article, a newly defined conchal floor arterial flap is proposed. The flap is based on the main stem of the posterior auricular artery and its venae comitantes. Two types of conchal floor arterial flaps were elevated: a proximally based chondral arterial flap and a distally based chondrocutaneous arterial flap. The proximally based flap was used for earlobe reconstruction, whereas the distally based flap was useful in the reconstruction of the upper auricle. Nine congenital auricular malformations were successfully corrected with this newly defined conchal floor flap procedure. This type of flap is easier to elevate, more reliable, and more versatile than the one currently in use.     

吻合皮下静脉的带蒂皮瓣修复四肢皮肤软组织缺损的效果分析

摘要 目的：探讨与分析吻合皮下静脉的带蒂皮瓣修复四肢皮肤软组织缺损的效果。方法：选择2018年12月到2021年12月在本院创伤造成的四肢皮肤软组织缺损60例患者作为研究对象,将其随机分为吻合皮下静脉带蒂皮瓣组与传统带蒂皮瓣组各30例。吻合皮下静脉带蒂皮瓣组给予吻合皮下静脉的带蒂皮瓣修复治疗,传统带蒂皮瓣组给予常规直接覆盖创面修复治疗。结果：所有患者都顺利完成手术,吻合皮下静脉带蒂皮瓣组围手术指标时间均较传统带蒂皮瓣组少（P<0.05）。吻合皮下静脉带蒂皮瓣组术后3个月的总有效率为96.7 %,高于传统带蒂皮瓣组的76.7 %（P<0.05）。吻合皮下静脉带蒂皮瓣组术后3个月的并发症发生率较传统带蒂皮瓣组低（P<0.05）。吻合皮下静脉带蒂皮瓣组术后6个月的感觉功能恢复情况好于传统带蒂皮瓣组（P<0.05）。结论：吻合皮下静脉的带蒂皮瓣能促进患者的创面愈合,提高治疗效果,减少并发症,加快恢复患者的四肢皮肤软组织缺损。     

口腔颌面部肿瘤患者术后缺损的外侧皮瓣修复术与前臂皮瓣修复术对比研究

摘要 目的：探讨口腔颌面部肿瘤患者术后缺损的外侧皮瓣修复术与前臂皮瓣修复术对比。方法：选取遂宁市中心医院（我院）2015年8月到2020年8月共收治的120例口腔颌面部肿瘤患者,所有患者通过肿瘤切除术后均出现组织缺损现象,对所有组织缺损的患者依照不同的皮瓣修复方式分为两组,其中应用外侧皮瓣修复术的68例患者分为外侧皮瓣修复组,应用前臂皮瓣修复术的52例患者分为前臂皮瓣修复组,对比两组的皮瓣修复效果,治疗后的口腔功能恢复情况,瓣成活率、术后皮瓣危象率以及血管吻合时间,并发症情况。结果：外侧皮瓣修复组的总有效率为95.59 %,前臂皮瓣修复组的总有效率为84.62 %,外侧皮瓣修复组明显高于前臂皮瓣修复组（P＜0.05）;外侧皮瓣修复组患者的外形修复、语言功能、咀嚼功能、吞咽功能以及口腔闭合评分明显高于前臂皮瓣修复组（P＜0.05）;两组的皮瓣成功率均比较高对比无明显差异（P＞0.05）,两组的术后皮瓣危象率比较低,对比无明显差异（P＞0.05）,血管吻合时间对比无明显差异（P＞0.05）;对比两组并发症发生情况发现,外侧皮瓣修复组的总并发症发生率为2.94 %,前臂皮瓣修复组并发症发生率为17.31 %,外侧皮瓣修复组明显低于前臂皮瓣修复组（P＜0.05）。结论：对口腔颌面部肿瘤患者术后缺损患者应用外侧皮瓣修复术能够提升患者的皮瓣修复效果,提升患者的口腔功能恢复情况,减少并发症的发生,安全性好,值得临床应用推广。     

Innervated radial thenar flap combined with radial forearm flap transfer for thumb reconstruction

A radial thenar flap combined with radial forearm flap was used for the reconstruction of the ipsilateral thumb in four patients. Vascular supply of the combined flap was based on the radial artery and extending the vascular pedicle to the superficial palmar branch of the radial artery. The flap was sensated by the palmar branch of the superficial radial nerve. The size of the flap averaged 15 x 5 cm and the innervated region of the thenar eminence was an area approximately 5 x 3 cm located over the proximal parts of the abductor pollicis brevis and opponens pollicis muscles. The flap was transferred as a free flap in three patients and as an advancement flap in one patient. The flaps survived completely without complications. Satisfactory restoration of sensation was achieved in the flap area, as shown by 6 mm of average moving two-point discrimination. This combined flap may be a feasible reconstructive option for large palmar defects of the fingers such as degloving injuries.