The versatility of the pudendal thigh fasciocutaneous flap used as an island flap

The pudendal thigh flap is a sensate fasciocutaneous flap based on the terminal branches of the superficial perineal artery, which is a continuation of the internal pudendal artery. Several authors have reported using this axial patterned flap in a bilateral fashion to reconstruct the vagina, mostly in patients with vaginal atresia. The technique is simple, safe, and reliable, and no stents or dilators are required. The reconstructed vagina has a natural angle and is sensate. The donor site in the groin can be closed primarily with an inconspicuous scar.The distinct advantages of this flap widen its indications to several other pathologies. In this article, the authors report on the bilateral use of the flap to reconstruct a vagina in patients with congenital atresia (n = 8) and after oncological resection (n = 5). Furthermore, the versatility of this island flap is also demonstrated by its use in a unilateral fashion in patients with recurrent or complex rectovaginal fistulas (n = 4) and in two patients with a defect of the posterior urethra in a heavily scarred perineum.All 31 pudendal thigh flaps survived completely. Some wound dehiscence was observed in two patients. Two other patients required a minor correction at the introitus of the vagina. The functional outcome was excellent in all patients, despite the presence of some hair growth in the flaps.This article discusses the expanding indications of this versatile flap and the refinements in operative technique.     

Reconstruction of Achilles tendon and calcaneus defects with skin-aponeurosis-bone composite free tissue from the groin region

Eight patients had reconstructive surgery for soft-tissue, associated Achilles tendon, and calcaneus defects on the posterior aspect of the ankle. In group A, those patients with skin, soft-tissue, and Achilles tendon loss were treated with free groin flaps that included sheets of the external oblique aponeurosis based on the superficial circumflex iliac vessel. The groin flap provided skin coverage, and the aponeurosis was rolled to form a tendon-like structure to replace the Achilles tendon. In group B, those patients with an additional calcaneus bone loss were treated with free iliac osteocutaneous flaps, together with the external oblique aponeurosis based on the deep circumflex iliac vessel. The iliac bone was then utilized to reconstruct the calcaneus defect. All composite free tissue transfers were successful, except in two group B patients who suffered partial skin loss. The advantages of this technique are (1) a single, one-stage procedure, (2) faster wound healing with fewer adhesions of the reconstructed Achilles tendon, and (3) good cosmesis and minimal morbidity at the donor site.     

A method of reconstructing a pendulous breast utilizing the tissue expander

It is possible to reconstruct a breast mound of almost any size by utilizing tissue expansion. In order to produce a pendulous breast which is also ptotic, the tissue-expansion technique has been combined with two other procedures. A new technique is being introduced. It is that of elevating the lower third of the mature breast capsule surrounding the tissue expander at the time the permanent prosthesis is to be exchanged for the expander. The established techniques of inframammary fold reconstruction of Pennisi and Ryan are used to provide pedicle skin coverage for the undersurface of the breast and the bed of the elevated capsule. Internal and external surgical approaches are described, and two examples of each are illustrated. Breasts reconstructed in this manner have remained pendulous structures. Some loss of the initial degree of ptosis has been noted in some cases.     

A classification system and reconstructive algorithm for acquired vaginal defects

Although multiple flaps have been used for vaginal reconstruction, a logical approach to reconstruction of these often complex defects has not been described. The objective of this study was to establish a classification system for acquired vaginal defects and to develop a reconstructive algorithm derived from this system. This study is a retrospective review of a 7-year experience with 51 flaps in 37 consecutive vaginal reconstructions. Twenty-two partial defects and 15 circumferential defects were reconstructed in 35 patients. Average patient age was 48 years (range, 19 to 69 years). Of the 22 patients with partial vaginal defects, six involved primarily the anterior and lateral wall and 16 the posterior vaginal wall. Among the 15 patients with circumferential defects, four included only the upper two-thirds of the vagina and 11 encompassed the entire vagina. On the basis of these defects, a classification system was developed. Partial defects involving the anterior or lateral vaginal wall were classified as type IA defects and were reconstructed primarily with pedicled Singapore fasciocutaneous flaps. Partial defects involving the posterior wall were classified as type IB and were reconstructed with pedicled rectus abdominis myocutaneous flaps. Circumferential defects involving the upper two-thirds of the vagina were classified as type IIA defects and were reconstructed with a rolled rectus flap or, less commonly, sigmoid colon (one patient). Total circumferential defects, type IIB, were reconstructed largely with bilateral gracilis flaps. Six patients had major complications, including one perioperative death, one complete flap loss, one partial flap loss, and three pelvic abscesses. Three patients had minor complications that included delayed wound healing and donor-site infection. Vaginal defects can be categorized into one of four types on the basis of the location and extent of resection. Flap selection is determined on the basis of the type of defect. Using this algorithm, immediate vaginal reconstruction with pedicled regional flaps can be performed with minimal patient morbidity and few surgical complications.     

A new approach to blood flow simulation in vascular networks

A proper analysis of blood flow is contingent upon accurate modelling of the branching pattern and vascular geometry of the network of interest. It is challenging to reconstruct the entire vascular network of any organ experimentally, in particular the pulmonary vasculature, because of its very high number of vessels, complexity of the branching pattern and poor accessibility in vivo. The objective of our research is to develop an innovative approach for the reconstruction of the full pulmonary vascular tree from available morphometric data. Our method consists of the use of morphometric data on those parts of the pulmonary vascular tree that are too small to reconstruct by medical imaging methods. This method is a three-step technique that reconstructs the entire pulmonary arterial tree down to the capillary bed. Vessels greater than 2 mm are reconstructed from direct volume and surface analysis using contrast-enhanced computed tomography. Vessels smaller than 2 mm are reconstructed from available morphometric and distensibility data and rearranged by applying Murray's laws. Implementation of morphometric data to reconstruct the branching pattern and applying Murray's laws to every vessel bifurcation simultaneously leads to an accurate vascular tree reconstruction. The reconstruction algorithm generates full arterial tree topography down to the ?rst capillary bifurcation. Geometry of each order of the vascular tree is generated separately to minimize the construction and simulation time. The node-to-node connectivity along with the diameter and length of every vessel segment is established and order numbers, according to the diameter-de?ned Strahler system, are assigned. In conclusion, the present model provides a morphological foundation for future analysis of blood flow in the pulmonary circulation     

The extended vertical rectus abdominis myocutaneous flap for breast reconstruction

The extended vertical rectus abdominis myocutaneous flap has been used in 34 patients for breast reconstruction after radical mastectomy. This flap can reconstruct a large ptotic breast mound and fill the infraclavicular and axillary areas. The operative technique and a discussion of the method are presented. There are several advantages to the extended vertical rectus abdominis myocutaneous flap. First, the main advantage of this flap is its reliable vascular supply, which can reach to the infraclavicular and axillary areas. Second, the large volume of this flap can reconstruct the large ptotic breast, fill the infraclavicular hollow, and create an axillary fold. Third, no lower abdominal wall hernias have developed, and use of alloplastic abdominal wall reinforcement is not necessary. Finally, the simultaneous beneficial effect of horizontal abdominoplasty, which further enhances the patient's body image by narrowing the waist, is unique to this vertical abdominal flap. The disadvantages of this flap include (1) the midline abdominal scar, (2) an umbilical scar on the reconstructed breast, and (3) in principle, inappropriateness for the patient who desires pregnancy postoperatively.     

Homologous control of protein signaling networks

In a previous paper we introduced a method called augmented sparse reconstruction (ASR) that identifies links among nodes of ordinary differential equation networks, given a small set of observed trajectories with various initial conditions. The main purpose of that technique was to reconstruct intracellular protein signaling networks.In this paper we show that a recursive augmented sparse reconstruction generates artificial networks that are homologous to a large, reference network, in the sense that kinase inhibition of several reactions in the network alters the trajectories of a sizable number of proteins in comparable ways for reference and reconstructed networks. We show this result using a large in-silico model of the epidermal growth factor receptor (EGF-R) driven signaling cascade to generate the data used in the reconstruction algorithm.The most significant consequence of this observed homology is that a nearly optimal combinatorial dosage of kinase inhibitors can be inferred, for many nodes, from the reconstructed network, a result potentially useful for a variety of applications in personalized medicine.     

Nasal reconstruction based on aesthetic subunits in Orientals

Reconstruction based on the aesthetic subunit principle has yielded good aesthetic outcomes in patients with moderate to severe nasal defects caused by trauma or tumor resection. However, the topographic subunits previously proposed are often unsuitable for Orientals. Compared with the nose in white patients, the nose in Orientals is low, lacks nasal muscle, and has a flat glabella; the structural features of the underlying cartilage and bone are not distinctly reflected in outward appearance. The authors devised aesthetic subunits suitable for Orientals, and they used these units to reconstruct various parts of the nose. The major difference between these units and those presented previously is the lack of soft triangles and the addition of the glabella as an independent unit. The authors divided the nose into the following five topographic units: the glabella, the nasal dorsum, the nasal tip, and the two alae. The border of the nasal dorsum unit was extended to above the maxillonasal suture. The basic reconstruction techniques use a V-Y advancement flap from the forehead to reconstruct the glabella, an island flap from the forehead to reconstruct the nasal dorsum and nasal tip, a nasolabial flap to reconstruct an ala, and a malar flap to reconstruct the cheek. A combination of flaps was used when the defect involved more than one unit. This concept was used for nasal reconstruction in 24 patients. In one patient undergoing reconstruction of the nasal dorsum and in one undergoing reconstruction of the nasal tip, the texture of the forearm flap did not match well, which resulted in a slightly unsatisfactory aesthetic outcome. In one patient in whom the glabella, nasal dorsum, and part of the cheek were reconstructed simultaneously, a web was formed at the medial ocular angle, and a secondary operation was subsequently performed using Z-plasty. In one patient undergoing reconstruction with a forehead flap, defatting was required to reduce the bulk of the subcutaneous flap pedicle at the glabella. However, suture lines were placed in the most inconspicuous sites in all patients, and the use of a trapdoor contraction emphasized the three-dimensional appearance of the nose. The use of these aesthetic subunits for reconstruction offers several advantages, particularly in Oriental patients. Because the nasal dorsum is reconstructed together with the side walls, tenting of the nasal dorsum is avoided, which prevents a flat appearance of the nose. A forehead flap is useful in the repair of complex defects. Defects of the alae should be separately reconstructed with a nasolabial flap to enhance the effect of the trapdoor contraction and to highlight the three-dimensional appearance of the nose. Candidates for reconstruction should be selected on the basis of nasal structure. The results suggest that these units can also be used in some white patients.     

快速微波热声层析成像在生物医学中的潜在应用

介绍了一种快速热声层析成像方法和装置,成功实现了生物组织的二维热声层析成像及异物检测.实验中采用频率为1.2 GHz的脉冲微波作为激发源,中心频率为3.5 MHz的320振元线性阵列探测器接收热声信号,然后用有限场滤波反投影方法重建得到热声层析图像.与原有方法相比,勿需全方位扫描采集数据,能大量节省时间,重建图像的对比度和抗噪声能力有极大提高.该方法和系统有望应用于乳腺癌早期检测、体内异物检测、微波热疗效果监测等方面.     

Challenges to be faced in the reconstruction of metabolic networks from public databases

In the post-genomic era, the biochemical information for individual compounds, enzymes, reactions to be found within named organisms has become readily available. The well-known KEGG and BioCyc databases provide a comprehensive catalogue for this information and have thereby substantially aided the scientific community. Using these databases, the complement of enzymes present in a given organism can be determined and, in principle, used to reconstruct the metabolic network. However, such reconstructed networks contain numerous properties contradicting biological expectation. The metabolic networks for a number of organisms are reconstructed from KEGG and BioCyc databases, and features of these networks are related to properties of their originating database.     

Reconstructing muscle activation during normal walking: a comparison of symbolic and connectionist machine learning techniques

One symbolic (rule-based inductive learning) and one connectionist (neural network) machine learning technique were used to reconstruct muscle activation patterns from kinematic data measured during normal human walking at several speeds. The activation patterns (or desired outputs) consisted of surface electromyographic (EMG) signals from the semitendinosus and vastus medialis muscles. The inputs consisted of flexion and extension angles measured at the hip and knee of the ipsilateral leg, their first and second derivatives, and bilateral foot contact information. The training set consisted of data from six trials, at two different speeds. The testing set consisted of data from two additional trials (one at each speed), which were not in the training set. It was possible to reconstruct the muscular activation at both speeds using both techniques. Timing of the reconstructed signals was accurate. The integrated value of the activation bursts was less accurate. The neural network gave a continuous output, whereas the rule-based inductive learning rule tree gave a quantised activation level. The advantage of rule-based inductive learning was that the rules used were both explicit and comprehensible, whilst the rules used by the neural network were implicit within its structure and not easily comprehended. The neural network was able to reconstruct the activation patterns of both muscles from one network, whereas two separate rule sets were needed for the rule-based technique. It is concluded that machine learning techniques, in comparison to explicit inverse muscular skeletal models, show good promise in modelling nearly cyclic movements such as locomotion at varying walking speeds. However, they do not provide insight into the biomechanics of the system, because they are not based on the biomechanical structure of the system.     

Functional reconstruction using a depressor anguli oris musculocutaneous flap for large lower lip defects, especially for elderly patients

Described here is a new technique to reconstruct large lower lip defects using one or two musculocutaneous island flaps, which includes an innervated depressor anguli oris muscle and has a facial artery in its pedicle. Vermilion is simultaneously reconstructed using a mucosal transposition flap. Three patients who had a total lower lip defect and five patients who had a defect larger than one-half of the lower lip were treated by our procedure. All the flaps survived completely without any signs of vascular stasis. In six patients, sphincter function and sensation appeared within 3 months after surgery. In one patient who needed a total lower lip reconstruction, the depressor anguli oris muscle was atrophic and the motor nerve could not be found. This patient could not regain motion. One other patient complained of a sialorrhea accompanied by sensory loss; however, his sensation improved within 6 months after surgery. All of the reconstructed lower lips were large enough to enable the patient to wear dentures and were of a cosmetically acceptable appearance 1 year after surgery.     

The facial restoration of Antal Simon, a Hungarian priest-teacher of the 19th c.

A large series of well documented, naturally mummified individuals were discovered during reconstruction works at the Dominican church in Vác in 1994--1995. Among them was Antal Simon (1772--1808), a well-known priest and teacher, the director of the Institute of the Deaf in Vác in the 19th century. His remains were used to reconstruct the facial appearance, employing standard techniques. There is an authentic painted portrait of him. The finished facial reconstruction was compared to this portrait. As a measure of the effectiveness of the reconstruction, the technique of superimposition was also used, which represented a direct comparison of the features of the portrait with those of the reconstructed face. The topographical, morphological and anatomical characteristics of the two faces were compared with the following results: 62% of the reconstructed traits showed great resemblance to the original face, 35% showed close resemblance and 3% showed approximate resemblance.     

Separation of cytoplasts and whole cells using density gradients of renografin.

Cytoplasts prepared from L929 or Hepa-2 cells were separated from whole cells using density gradients of renografin. Using this technique, cytoplasts can be isolated from cell lines which cannot be routinely enucleated with an efficiency of 100%. The purified cytoplasts excluded the vital dye trypan blue and were utilized in nuclear transplantation experiments to reconstruct whole viable cells capable of division. In addition, the renografin gradient technique was used to separate the newly reconstructed cells from any contaminating "non-renucleated" cytoplasts. This will permit immediate biochemical characterization of cytoplasmic-nuclear hybrid cells without interference from contaminating cytoplasts.     

Three-dimensional reconstruction using an adaptive simultaneous algebraic reconstruction technique in electron tomography

Three-dimensional (3D) reconstruction of electron tomography (ET) has emerged as an important technique in analyzing structures of complex biological samples. However most of existing reconstruction methods are not suitable for extremely noisy and incomplete data conditions. We present an adaptive simultaneous algebraic reconstruction technique (ASART) in which a modified multilevel access scheme and an adaptive relaxation parameter adjustment method are developed to improve the quality of the reconstructed 3D structure. The reconstruction process is facilitated by using a column-sum substitution approach. This modified multilevel access scheme is adopted to arrange the order of projections so as to minimize the correlations between consecutive views within a limited angle range. In the adaptive relaxation parameter adjustment method, not only the weight matrix (as in the existing methods) but the gray levels of the pixels are employed to adjust the relaxation parameters so that the quality of the reconstruction is improved while the convergence process of the reconstruction is accelerated. In the column-sum substitution approach, the computation to obtain the reciprocal of the sum for the columns in each view is avoided so that the needed computations for each iteration can be reduced. Experimental results show that the proposed technique ASART is better based on objective quality measures than other methods, especially when data is noisy and limited in tilt angles. At the same time, the reconstruction by ASART outperforms that of simultaneous algebraic reconstruction technique (SART) in speed.     

Management of complex groin wounds: preferred use of the rectus femoris muscle flap

This study reviews our experience with the rectus femoris muscle flap for complex groin wound reconstruction. Over the past 5 years, the rectus femoris has become our routine method of groin wound reconstruction. The rectus femoris is harvested through a midanterior incision extending over the distal two-thirds of the thigh. The muscle is elevated on its pedicle and transposed into the groin wound defect either directly or through an intervening skin bridge. Hospital and outpatient records were reviewed for all patients undergoing groin wound reconstruction with this technique from 1999 through 2003. Thirty-seven rectus femoris muscle flaps were performed in 33 patients. The mean patient age was 65.3 years (range, 25 to 88 years). Thirty groin wounds (81.1 percent) occurred after infrainguinal revascularization, 23 (76.7 percent) of which contained prosthetic material. Five (21.7 percent) of these wounds had their prosthetic material removed at the time of reconstruction. The remaining seven groin wounds (18.9 percent) occurred after femoral vessel cannulation for either cardiac or transplant surgery. There were no intraoperative mortalities and no anastomotic hemorrhages. There were no flap losses. Thirty-five of the 37 treated wounds healed (94.6 percent), 26 primarily (70.3 percent) and nine (24.3 percent) after delayed healing and contracture. Reoperation was performed in one patient for flap readvancement and in three patients for prosthetic graft removal after initial flap reconstruction. Two patients (6.1 percent) died during their hospitalization with persistent open groin wounds after flap reconstruction. All muscle flap donor incisions healed, with only two (5.4 percent) experiencing minimal delayed healing. There were no donor-site wound infections and no donor sites required reoperation. Thirty-three groin wounds (89.2 percent) demonstrated culture-positive microbial infection, 15 (45.5 percent) of which were polymicrobial. The 30-day mortality rate was 15.2 percent and the 6-month mortality rate increased to 27.2 percent, with multisystem organ failure as the most common cause. The rectus femoris muscle flap is an effective and reliable means of complex groin wound reconstruction. The muscle flap is dependable and the donor site is not problematic, even in the presence of peripheral vascular disease. On the basis of our clinical results, we believe that the rectus femoris muscle flap is the flap of choice for groin wound reconstruction.     

Polymerase reaction without primers throughout for the reconstruction of full-length cDNA from products of rapid amplification of cDNA ends (RACE)

Rapid amplification of cDNA ends (RACE) has widely been used to determine both ends of the cDNA from its partial sequence. Conventionally, 5'- and 3'-RACE products were ligated at a restriction site in the overlap region to reconstruct the full-length cDNA; however, reconstruction is difficult if no appropriate restriction enzymes are available. Here, we report a novel method to reconstruct full-length cDNA with DNA polymerase. Instead of usual PCR, chain reactions were avoided and the elongation time was shortened, which enables non-specific products or undesired point mutations to be minimized. We successfully reconstructed and TA-cloned a full-length cDNA of echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) fusion gene variant 2 from RACE products obtained from a surgically resected lung adenocarcinoma sample. We also evaluated some parameters to provide recommendations for this new method.     

Neovaginal construction with buccal mucosal grafts

Several surgical techniques have been designed to construct a neovagina that will be satisfying in appearance, function, and feeling when the vagina is congenitally absent. However, no method has yet been approved as a perfect solution. With the aim of solving the problems with conventional methods, the authors describe a new surgical technique that is simple and safe for treating vaginal agenesis. This technique consists of creating a mucosal lining of the neovaginal cavity using multiple full-thickness buccal mucosal patch grafts. Four patients with congenital absence of the vagina treated with this technique are presented. This surgical procedure created a mucus-providing lining inside the neovagina. Selecting the donor site in the oral region resulted in an inconspicuous donor-site scar. Histologically, the neovaginal lining was confirmed as mucosal, and the cream-colored viscous fluid found in the neovaginal cavity was confirmed as mucus. At a mean follow-up period of 15 months, the neovagina remained adequate in depth and width. All of the patients were interviewed to evaluate the function of the neovagina. Each patient reported having regular sexual intercourse and that the neovagina had felt normal to their partners. The encouraging results obtained in four cases suggest that this new technique deserves further application.     

A technique for transcervical intrauterine insemination of ewes

In commercial artificial insemination (AI) of sheep, fresh extended semen is deposited into the vagina or cervical os, or fresh extended or frozen semen is placed laparoscopically into the uterus. Transcervical intrauterine insemination of the ewe is not used commercially. In this study, methods of restraint and instrumentation for AI were evaluated and modified to produce a transcervical intrauterine technique suitable for commercial application. Four methods of restraint, four vaginal specula, three forceps and four instruments suitable for transcervical passage were compared. From these comparisons a technique was developed in which the ewes were positioned in dorsal recumbency with their hindquarters elevated. The vagina was dilated using a duck-billed speculum, the cervix was grasped and retracted using forceps, and an inseminating instrument was introduced into the cervical opening and manipulated through the cervical canal. The technique was repeated on 89 mature, multiparous ewes: the difficulty in locating the cervical opening, the force required to retract the cervix and the time required to penetrate into the uterus were recorded. Uterine penetration was achieved in 82% of the ewes. This technique has the potential to be applied in commercial artificial insemination programs of sheep.     

双源CT三维重建前交叉韧带移植物新技术

目的:探讨双源CT(DSCT)三维重建前交叉韧带(anterior cruciate ligament,ACL)重建术后移植物的技术方法。方法:对30例ACL损伤后移植重建术后患者进行DSCT扫描,利用软件三维重建ACL移植物的三维图像,对图像效果进行分析。结果:采用设定的参数和方法,30例患者的ACL移植物均获得三维重现,其中24例获得清晰的移植物图像,6例移植物图像略模糊。结论:DSCT可以重建出移植术后ACL移植物的三维图像,对临床检验、评估重建技术、修正重建方法、实现解剖重建有重大价值。