A mathematical assessment of suture line stress in the end-to-side anastomosis—I. Steady flow

The tensile force acting on the suture line connecting a synthetic graft to a host artery in an end-to-side anastomosis is shown to increase from 23,000 to 55,000 dyn as the ratio of the graft-artery area increased from 0.5 to 1.2. The angle of the end-to-side anastomosis is shown to have negligible effect on the suture line stress. The stresses calculated for 3-0. Tevdek suture subjected to the above forces are shown to be one-fiftieth of the yield strength of that suture material. However, it is suggested that such suture forces could cause the suture to tear through the host arterial wall unless sufficient sutures per cm, and maximum suture-host artery contact area are established.     

Combination of two pseudoaneurysms in a patient 6 years after ascending aorta and aortic valve replacement

BACKGROUND: We report successful treatment of a patient 6 years after ascending aorta and aortic valve replacement suffering from a combination of two pseudoaneurysms. The first of them originated from the coronary ostial suture line and the second pseudoaneurysm originated from the distal suture line. METHODS: We performed re-replantation of the left main trunk to the prosthesis and then we resected the pseudoaneurysm originating from the distal suture line and we replaced the entire aorta by a vascular graft. RESULTS: The postoperative convalescence was uneventful, the patient was discharged two weeks after the surgery. The patient is currently in a very good condition one year after the surgery. CONCLUSIONS: Coronary ostial pseudoaneurysm in patients after ascending aorta and aortic valve replacement with the use of "button technique" is a quite rare situation. The combination of two pseudoaneurysms originating from different suture lines in one patient seems to be unique in literature reviews.     

Eine abnorme,stark vereinfachte lobenlinie beiBrasilia decipiens (Buckman)

An abnormal, very simplified suture on the right side of aBrasilia decipiens (Buckman) of the Inferior Oolite from Dorset/GB is described. The development of the abnormal suture indicates that the mural ridge served as a line of attachment for the epithelium the septum was built of.     

Successful treatment for exposure of a dacron aorta, with surrounding infection: case report.

The treatment of the patient with an exposed vascular implant should usually be in the hands of an expert vascular surgeon. In certain instances, such as when the exposed area is not close to a suture line and no fistulous tracts connect the exposed area to either suture line, plastic surgery can solve the problem. We present a case of an exposed aortic prosthesis which was successfully treated by removing devitalized tissue, turning a pectoralis major muscle flap over the implant, and closing the skin and subcutaneous tissue over the muscle flap.     

Thriving at high hydrostatic pressure: the example of ammonoids (extinct cephalopods)

Ammonoids are a group of extinct mollusks belonging to the same class of the living genus Nautilus (cephalopoda). In both Nautili and ammonoids, the (usually planospiral) shell is divided into chambers separated by septa that, during their lifetime, are filled with gas at atmospheric pressure. The intersection of septa with the external shell generates a curve called the suture line, which in living and most fossil Nautili is fairly uncomplicated. In contrast, suture lines of ancient ammonoids were gently curved and during the evolution of the group became highly complex, in some cases so extensively frilled as to be considered as fractal curves. Numerous theories have been put forward to explain the complexity of suture ammonoid lines. Calculations presented here lend support to the hypothesis that complex suture lines aided in counteracting the effect of the external water pressure. Additionally, it is suggested that complex suture lines diminished shell shrinkage caused by water pressure, and thus aided in improving buoyancy. Understanding the reason for complex sutures in ammonoids represents an important issue in paleobiology with potential applications to the problem of the resistance of hollow mechanical structures subjected to high pressure.     

The systematic position of the Lower Cretaceous heteromorphic ammonite <Emphasis Type="Italic">Pictetia</Emphasis> Uhlig, 1883

The heteromorphic ammonite genus Pictetia has previously been included in the Lytoceratidae. A reassessment of literature data and a detailed analysis of the suture shows that Pictetia lacks a septal lobe as well as a bifid internal lobe and lateral lobe, all features indicative of the Lytoceratidae. This and the quadrilobate suture line, combined with the loose coiling of the shell, indicate that it should be included in the polyphyletic suborder “Ancyloceratina”. Any further systematic assessment is impossible at the moment.     

TGF-beta2 stimulates cranial suture closure through activation of the Erk-MAPK pathway

Cranial sutures are important growth sites of the skull. During suture closure, the dura mater is one of the most important sources of various positive and negative regulatory signals. Previous results indicate that TGF-beta2 from dura mater strongly accelerates suture closure, however, its exact regulatory mechanism is still unclear. In this study, we confirmed that removal of dura mater in calvarial organ culture strongly accelerates sagittal suture closure and that this effect is further enhanced by TGF-beta2 treatment. TGF-beta2 stimulated cell proliferation in the MC3T3-E1 cell line. Similarly, it stimulated the proliferation of cells in the sutural space in calvarial organ culture. Furthermore, TGF-beta2-mediated enhanced cell proliferation and suture closure were almost completely inhibited by an Erk-MAPK blocker, PD98059. These results indicate that TGF-beta2-induced activation of Erk-MAPK is an important signaling component that stimulates cell proliferation to enrich osteoprogenitor cells, thereby promoting their differentiation into osteoblasts to achieve a rapid calvarial bone expansion.     

Meloplication of the malar fat pads by percutaneous cable-suture technique for midface rejuvenation: outcome study (392 cases, 6 years' experience)

The aging anterior midface is restored by reversing the contour undulations produced by sagging of the malar fat pad complex toward the nasolabial line. The convex irregularities include the exposed bulges of the post-septal fat, the unveiled malar bag, and the prominent nasolabial fold. The depressed irregularities are represented by the cresent-shaped hollow at the lid-cheek junction, the accentuated nasojugal groove, and the deepening nasolabial line. Repositioning of the ptotic malar fat pad, among other elements of meloplasty, represents a key procedure. In this study, the malar fat pad has been defined as a fan-shaped structure by external anatomic landmarks that correlate closely to the findings in cadaveric dissections and clinical cases, confirmed by the findings of spiral computed tomographic scanning. A simple but powerful adjustable and long-lasting percutaneous suture elevation technique was developed over the past 6 years by the senior author (G.H.S.) to reposition the fat pad in a superolateral direction. Through a dot incision within the nasolabial line, a permanent CV-3 Gore-Tex (or 4-0 clear Prolene) suspension suture, looped through a Gore-Tex anchor graft, suspends the malar fat pad in a direction perpendicular to the nasolabial line. A second suspension system is identically passed through another lower dot incision to broaden the repositioning vectors on the malar fat pad. Tension on each of the paired suture ends elevates the malar fat pad by 1 to 3 mm as measured from the nasolabial dot incisions. The sutures are fixed to the deep temporal fascia through a Gore-Tex tab, effectively stabilizing the soft-tissue repositioning. This maneuver may be performed in younger patients who present with an isolated malar fat pad ptosis without excess facial skin. The procedure may also be incorporated into open rhytidectomies to address this recalcitrant area along with superficial musculoaponeurotic system tightening. A total of 392 patients since 1995 underwent suture elevation of the malar fat pads. An outcome study indicated that the usage of two permanent sutures with Gore-Tex anchor grafts since 1998 resulted in improvement in midface rejuvenation of over 82 percent. Early and late complication rates were small and temporary. Patient acceptance was excellent, indicative of the benefits of anatomic repositioning of the malar fat pad complex.     

Temporary tarsorrhaphy suture to prevent or treat scleral show and ectropion secondary to laser resurfacing or laser blepharoplasty

The temporary tarsorrhaphy suture is introduced as a simple effective technique to prevent scleral show or ectropion secondary to laser skin resurfacing or laser blepharoplasty. In all but severe cases of prior existing scleral show or ectropion, the temporary tarsorrhaphy suture has been completely effective. It is also successfully used to prevent scleral show and ectropion for patients with poor lid snap and loss of elasticity of the lower eyelid at the time of laser skin resurfacing and blepharoplasty. A 5-0 Prolene suture is placed through the gray line to approximate the upper and lower eyelids and is left in place for 5 days. This supports the lower eyelid during the critical period of dermal and epidermal regeneration and during the formation of new collagen and elastin.     

大鼠心肌梗死模型建立方法选择及心电图表现

目的探讨构建心肌梗死模型的大鼠左冠状动脉结扎位置及心电图特点。方法 SD大鼠经麻醉后,气管切开插管及连通呼吸机,打开左侧胸腔后分别在距离左心耳尖端约2 mm水平处(低位结扎组)与在距主动脉根部约3 mm处(高位结扎组)结扎左冠动脉,假手术组除不结扎冠脉外步骤同低位结扎组,术前术后分别行心电图检查,且4周后取出心脏行病理学检查及测定心肌梗死面积。结果高位结扎组大鼠心肌梗死面积约55.5%,总存活率13.3%;低位结扎组大鼠心肌梗死面积约36.2%,总存活率66.7%;假手术组大鼠无心肌梗死,存活率100%。大鼠体表心电图在非心肌梗死者QRS-T波群呈成"M"型波,在心肌梗死者R波与T波融合成高大的帐篷状单波,无明显ST段。4周后心肌组织形态学特点符合心肌梗死的病理改变。结论距大鼠主动脉根部约3 mm结扎左冠状动脉,不能满足实验需要;距离左心耳尖端约2 mm水平结扎左冠状动脉,能满足实验需要;大鼠的体表心电图无明显ST段。     

Characteristics of the infant Apert skull and its subsequent development

The purpose of the paper is to describe and analyze the infant Apert skull with emphasis on the calvaria and its early postnatal development. Skull radiographs of 16 Apert syndrome patients were examined (12 American, 4 Danish; 8 males, 8 females). The criterion for inclusion in the study was that the first skull film had to be obtained before 1 year of age. Study methods employed included plain skull radiographs, roentgencephalometric films in several projections, CT-scans, and 3-D reconstructions. Data from 2 dry skulls and 2 early cases from the literature were also evaluated The following findings were common to all cases during early infancy (less than 3 months): The coronal suture area was prematurely closed and was represented by a bone condensation line beginning at the cranial base, extending upwards, and having a characteristic posterior convexity. Anterior and posterior fontanelles were widely patent. The midline of the calvaria had a gaping defect which extended from the glabellar area to the posterior fontanelle via the metopic suture area, anterior fontanelle, and sagittal suture area. Bony islands of varying sizes were observed in the midline defect. The calvaria was hypomineralized. During the first 2-4 years of life, the midline defect was obliterated by coalescence of the enlarging bony islands without evidence of any proper formation of sutures. The calvaria became thicker with time and several cases developed increased digital markings and enlargement of the sella turcica. During infancy, the Apert skull with its gaping midline defect appears to permit adequate accommodation of the growing brain, albeit distorted in shape. Normal metopic, sagittal, and coronal sutures with interdigitations were not observed in a single instance; in contrast, the lambdoidal sutures appeared normal in all cases. The invariable findings of an extremely short squama and orbital part of the frontal bone together with the posterior convexity of the coronal bone condensation line suggest that growth inhibition in the sphenofrontal and coronal suture area has its onset very early in fetal life.     

A simple technique for closure of a palatal fistula using a conchal cartilage graft.

A simple technique for closure of a palatal fistula using a conchal cartilage graft as a substitute for nasal lining flaps is reported. This graft simplifies the repair of the palatal fistula and protects the suture line of the oral covering flaps from recurrence.     

Flow patterns in the radiocephalic arteriovenous fistula: an in vitro study.

A significant number of late failures of arteriovenous fistulae for haemodialysis access are related to the progression of intimal hyperplasia. Although the aetiology of this process is still unknown, the geometry of the fistula and the local haemodynamics are thought to be contributory factors. An in-vitro study was carried out to investigate the local haemodynamics in a model of a Cimino-Brescia arteriovenous (AV) fistula with a 30 degrees anastomotic angle and vein-to-artery diameter ratio of 1.6. Flow patterns were obtained by planar illumination of micro-particles suspended in the fluid. Steady and pulsatile flow studies were performed over a range of flow conditions corresponding to those recorded in patients. Quantitative measurements of wall shear stress and turbulence were made using laser Doppler anemometry. The flow structures in pulsatile flow were similar to those seen in steady flow with no significant qualitative changes over the cardiac cycle. This was probably the result of the low pulsatility index of the flow waveform in AV fistulae. Turbulence was the dominant feature in the vein, with relative turbulence intensity > 0.5 within 10 mm of the suture line decreasing to a relatively constant value of about 0.10-0.15 between 40 and 70 mm from the suture line. Peak and mean Reynolds shear stress of 15 and 20 N/m2, respectively, were recorded at the suture line. On the floor of the artery, peak values of temporal mean and oscillating wall shear stress of 9.22 and 29.8 N/m2, respectively. In the vein, both mean and oscillating wall shear stress decreased with distance from the anastomosis.     

Relative contribution of wall shear stress and injury in experimental intimal thickening at PTFE end-to-side arterial anastomoses

BACKGROUND: Intimal hyperplastic thickening (IHT) is a frequent cause of prosthetic bypass graft failure. Induction and progression of IHT is thought to involve a number of mechanisms related to variation in the flow field, injury and the prosthetic nature of the conduit. This study was designed to examine the relative contribution of wall shear stress and injury to the induction of IHT at defined regions of experimental end-to-side prosthetic anastomoses. METHODS AND RESULTS: The distribution of IHT was determined at the distal end-to-side anastomosis of seven canine Iliofemoral PTFE grafts after 12 weeks of implantation. An upscaled transparent model was constructed using the in vivo anastomotic geometry, and wall shear stress was determined at 24 axial locations from laser Doppler anemometry measurements of the near wall velocity under conditions of pulsatile flow similar to that present in vivo. The distribution of IHT at the end-to-side PTFE graft was determined using computer assisted morphometry. IHT involving the native artery ranged from 0.0+/-0.1 mm to 0.05+/-0.03 mm. A greater amount of IHT was found on the graft hood (PTFE) and ranged from 0.09+/-0.06 to 0.24+/-0.06 mm. Nonlinear multivariable logistic analysis was used to model IHT as a function of the reciprocal of wall shear stress, distance from the suture line, and vascular conduit type (i.e. PTFE versus host artery). Vascular conduit type and distance from the suture line independently contributed to IHT. An inverse correlation between wall shear stress and IHT was found only for those regions located on the juxta-anastomotic PTFE graft. CONCLUSIONS: The data are consistent with a model of intimal thickening in which the intimal hyperplastic pannus migrating from the suture line was enhanced by reduced levels of wall shear stress at the PTFE graft/host artery interface. Such hemodynamic modulation of injury induced IHT was absent at the neighboring artery wall.     

Prevention and treatment of wide scar and alopecia in the scalp: wedge excision and double relaxation suture

The visible linear scar of the scalp is a cosmetically serious complication of a scalp incision in scalp surgery, forehead lift, and craniofacial surgery, especially on the temporal scalp. Its causes are cicatrical alopecia and scar widening. To solve this problem, we performed the wedge excision of the scalp and the double relaxation suture of the galea in 2 patients undergoing facial surgery through the coronal approach and in 15 patients with scalp alopecia ranging from 0.5 to 3.0 cm in width. The wedge excision using the beveling incision at an angle of 30 degrees to the hair follicles preserves the deep hair follicles of the flap margins and allows the hair to grow into the scar, eventually preventing cicatricial alopecia and camouflaging the linear scar. The double relaxation suture of the trimmed galea with nonabsorbable suture with or without the relaxation incision minimizes skin tension for a long time, eventually preventing scar widening. This procedure was followed by the superficial skin suture for maintaining the skin sutures for a long time and avoiding the injury of the superficial hair follicles. In all patients, we observed an excellent cosmetic result of unnoticed scar line without complications during the follow-up period of 10 weeks to 6 months.     

A new interpretation of the female genitalia in Macrocyclops albidus (Copepoda, Cyclopidae)

The female genital structures of Macrocyclops albidus (Cyclopidae, Eucyclopinae) were studied using light and electron microscopy. The results confirm that the exterior genital area shows only a copulatory pore, located anteromedially on the ventral face of the genital double-somite, and paired gonopores (not directly visible), situated laterally under the P6 plates. An internal seminal receptacle, composed of several parts, is connected to the gonopores by ventro-lateral cuticular extensions or seminal ducts. The lateral site of communication shows a complex set of connections between the seminal receptacle and the oviducts (via the egg-laying ducts). The structure until now designated as ‘transverse ducts’, visible by transparency on the ventral face, is in fact constituted of internal cuticular thickenings resulting of the fusion of the 6th thoracic somite and the 1st abdominal somite forming the genital double-somite and appearing externally as a part of the suture line; the term ‘suture cord’ is proposed to designate it. The functioning of the system is explained.     

L’évolution chez les Phyllocerataceae,la variabilité des paramètres dimensionnels et relatifs. Variabilité de la complexité de la ligne cloisonnaire: Variabilité et paedomorphose

Evolution of the Phyllocerataceae, the variability of the dimensional and relative parameters. Variability of the complexity of the suture line. Variability and paedomorphosis. A recent study has shown the importance of heterochronies in the development of Phyllocerataceae. It was attractive to estimate with precision the variability of some morphological characters of the shell and of the suture line in order to study how this variability changed in the course of time (from Jurassic to terminal Cretaceous). This note gives the averages of the calculations of variability in dimensional and relative variables in the shell of Phylloceratidae and variability in the complexity C of their suture lines. Coefficient of variation V is the statistical parameter used here, because it allows the comparison between the dispersions of different populations. This study shows that the variability of the complexity in the suture line and h₁ + h₂ is more fluctuating among the taxa (usually subfamilies, genera and species) in which heterochrony is evident. On the other hand, the variability of other parameters (V₁, V₂, D) first grows and then slowly decreases till the branch or the lineage is extinct. This schema is mostly acceptable down to the Lower Cretaceous-Upper Cretaceous in the Tethys and in the marine shelf of Gondwana. In the family of Neophylloceratidae, very clearly in the Tethys, less clearly in marine shelf of Gondwana (it is less obvious in the genus Phyllopachyceras), the variability grows as far as the terminal Cretaceous. The extinction of this family may result from a catastrophic event and not from internal causes. In short, the decrease of variability comes before the extinction of the taxa and consequently it agrees with a Darwinian classic schema. On the other hand, the extinction of Neophylloceratidae that occurs when the variability is maximal probably takes place in another perspective, an external « catastrophic » event. To cite this article, B. Joly, C.R. Palevol 2 (2003).     

Effect of stretching on gene expression of beta1 integrin and focal adhesion kinase and on chondrogenesis through cell-extracellular matrix interactions

Differentiation of skeletal tissues, such as bone, ligament and cartilage, is regulated by complex interaction between genetic and epigenetic factors. In the present study, we attempted to elucidate the possible role of cell-extracellular matrix (ECM) adhesion on the inhibitory regulation in chondrogenesis responding to the tension force. The midpalatal suture cartilages in rats were expanded by orthopedic force. In situ hybridization for type I and II collagens, immunohistochemical analysis for fibronectin, alpha5 and beta1 integrins, paxillin, and vinculin, and cytochemical staining for actin were used to demonstrate the phenotypic change of chondrocytes. Immunohistochemical analysis for phosphorylation and nuclear translocation of extracellular signal-regulated kinase (ERK)-1/2 was performed. The role of the cell-ECM adhesion in the response of the chondroprogenitor cells to mechanical stress and the regulation of gene expression of focal adhesion kinase (FAK) and integrins were analyzed by using an in vitro system. A fibrous suture tissue replaced the midpalatal suture cartilage by the expansive force application for 14 days. The active osteoblasts that line the surface of bone matrix in the newly formed suture tissue strongly expressed the type I collagen gene, whereas they did not express the type II collagen gene. Although the numbers of precartilaginous cells expressing alpha5 and beta1 integrin increased, the immunoreactivity of alpha5 integrin in each cell was maintained at the same level throughout the experimental period. During the early response of midpalatal suture cartilage cells to expansive stimulation, formation of stress fibers, reorganization of focal adhesion contacts immunoreactive to a vinculin-specific antibody, and phosphorylation and nuclear translocation of ERK-1/2 were observed. In vitro experiments were in agreement with the results from the in vivo study, i.e. the inhibited expression of type II collagen and upregulation in integrin expression. The arginine-glycine-aspartic acid-containing peptide completely rescued chondrogenesis from tension-mediated inhibition. Thus, we conclude that stretching activates gene expression of beta1 integrin and FAK and inhibits chondrogenesis through cell-ECM interactions of chondroprogenitor cells.     

RECURRENT CARCINOMA OF THE RECTUM—Surgical Treatment

Following operations on the rectum for carcinoma, approximately half of the patients have recurrence in the perineum, pelvis, abdomen or at the suture line of anastomosis. The prognosis is almost uniformly poor and although the problems of management are complicated, dealing with them may give the patient worthwhile physical, emotional and economic benefits. Surgical procedures used in the treatment of the common types of recurrence are discussed.