Vacuum assisted closure for the treatment of sternal wounds: the bridge between débridement and definitive closure

A method to refine the treatment of sternal wounds using Vacuum Assisted Closure (V.A.C.) therapy as the bridge between débridement and delayed definitive closure is described. A retrospective review of 35 consecutive patients with sternal wound complications over a 2-year period (March of 1999 to March of 2001) was performed. The treatment of sternal wounds with traditional twice-a-day dressing changes was compared with the treatment with the wound V.A.C. device. An analysis of the number of days between initial débridement and closure, number of dressing changes, number and types of flaps needed for reconstruction, and complications was performed. Eighteen patients were treated with traditional twice-a-day dressing changes and 17 patients were treated with V.A.C. therapy alone. The two groups were similar regarding age, sex, type of cardiac procedure, and type of sternal wound. The V.A.C. therapy group had a trend toward a shorter interval between débridement and closure, with a mean of 6.2 days, whereas the dressing change group had mean of 8.5 days. The V.A.C. therapy group had a significantly lower number of dressing changes, with a mean of three, whereas the twice-a-day dressing change group had a mean of 17 (p < 0.05). Reconstruction required an average of 1.5 soft-tissue flaps per patient treated with traditional dressing changes versus 0.9 soft-tissue flaps per patient for those treated with V.A.C. therapy (p < 0.05). Before closure, there was one death among patients undergoing dressing changes and three in the V.A.C. therapy group, all of which were unrelated to the management of the sternal wound. Patients with sternal wounds who have benefited from V.A.C. therapy alone have a significant decrease in the number of dressing changes and number of soft-tissue flaps needed for closure. Finally, the V.A.C. therapy group had a trend toward a decreased number of days between débridement and closure.     

Internal fixation of the sternum in median sternotomy dehiscence.

Sternal dehiscence may be defined as separation of the bony sternum and manubrium following median sternotomy. It may occur at any time postoperatively and has various etiologies. Restoration of sternal integrity in sternal dehiscence is a challenging problem, particularly when associated with deep-seated infection. This report reviews a single-stage technique that virtually eliminates the infected sternotomy wound and provides anatomic reduction and stabilization of the sternum. Complete debridement of infected and/or nonviable soft tissue, bone, and cartilage is followed by pulse irrigation. Parallel stainless steel mandibular reconstruction plates are then placed on each side of the remaining sternum and wired together. One or more transmanubrial compression plates may be added. Bilateral pectoralis major musculocutaneous flap advancement and primary skin closure is performed over two to three closed suction drains. From January of 1994 to July of 1996, this technique was used by the same surgeon in 26 male and 4 female patients aged 43 to 78 years (mean = 61). Indications for the operation were sternal dehiscence with infection (osteomyelitis and/or mediastinitis) in 14 patients and sternal dehiscence without infection in 16 patients. All patients survived to discharge with mean time on the ventilator, intensive care unit length of stay, and postoperative length of stay of 0.7, 2, and 8 days, respectively. Choice and duration of antibiotics were based on culture results and operative findings. Subsequent hardware removal was necessary in one patient for hardware loosening and three patients for late periplate infection. A closed wound was eventually achieved in all 30 patients, and sternal stability was restored in 29 patients. In the management of sternal dehiscence, the described technique of internal fixation can provide anatomic sternal reduction and stabilization, elimination of infection, and wound closure in a single-stage operation. Successful outcomes were achieved despite the presence of severe infection.     

The integrated approach to suppurative mediastinitis: rewiring the sternum over transposed omentum

Acute mediastinitis after cardiopulmonary procedures remains a devastating complication and a challenge to the reconstructive surgeon. A review of the literature and our own experience confirm the need for early aggressive drainage followed by timely reconstruction. In carefully selected patients, the sternum may be reclosed, provided that omental tissue has been transposed into the defect between the myocardium and the posterior cortex of the sternum. The technique is outlined and the results are analyzed and compared with three additional patient subgroups: (1) sternal wounds rewired over drains, (2) sternal wounds rewired with drains and irrigation catheters, and (3) wounds closed by sternal excision and muscle-flap transposition. To date, nine omental transfers have been performed with complete success. Mediastinal drainage routinely ceases after 3 to 5 days, and hospitalization has averaged 10 to 14 days. Early open debridement allows establishment of drainage and permits close evaluation of the character of the bony sternum. Muscle flaps may then be used in those patients with multiply fractured or frankly necrotic sternal tissue, while sternal closure over omental flaps may be used in all other patients. Adherence to this protocol has allowed for bacteriologic control of the wound, minimal morbidity, and no mortality.     

Treatment of sternal nonunion with the Dall-Miles cable system

We have used this technique in two patients. One had early sternal dehiscence with presternal infection, and the other had late sternal nonunion. Uncomplicated sternal union was achieved in both patients. The cables were nonpalpable in both patients, but they were removed in one patient at that patient's request. This method of using Dall-Miles cerclage cables is a straightforward and efficacious method of open reduction and internal fixation of the sternum. It is indicated for patients with chronic sternal nonunion or early postoperative separation of the sternal fragments and may be used even in the presence of an infection limited to the presternal space after adequate debridement and irrigation have been performed. Any recurrent superficial infection, although unlikely, can be cured by hardware removal after osseous union has been obtained. For sternal separation without fractures, four cables may simply be placed around the sternal halves and their tension increased. In the case of sternal fractures, the cables may be placed in figures of eight or in other woven configurations as needed for each individual case.     

First-line treatment of deep sternal infection by a plastic surgical approach: superior results compared with conventional cardiac surgical orthodoxy

A majority of cardiac surgeons manage deep sternal infection with sternal wound debridement, rewiring, and closed drainage, with or without antibiotic saline tube irrigation (the traditional approach). The authors' experience with the traditional approach was unsatisfactory; therefore, they undertook a radical change in management: an immediate plastic surgical approach. Hence, deep sternal infection was managed by immediate debridement followed by a bilateral pectoralis major myocutaneous advancement flap with greater omental transposition (PMOFR). This is the first such study reporting the effect of this strategy on the rate of eradication of deep sternal infection, intensive care unit stay, total hospital length of stay, major complications, mortality, intermediate survival, and patient satisfaction, as compared with the traditional approach used by cardiac surgeons at the authors' institution.All patients who developed a deep sternal infection from 1993 through 1998 at a tertiary teaching hospital were included. In the PMOFR group (nine patients), after a diagnosis of clinical sternal wound infection, debridement was performed immediately, either if sternal dehiscence occurred or in the absence of clinical dehiscence, if the patient or the sternotomy wound did not clinically improve with medical therapy within 48 hours from suspected diagnosis. Open irrigation and packing for 2 to 4 days was followed by treatment with a PMOFR. In the group treated using the traditional approach (12 patients), no predetermined plan was present. Thus, at the cardiac surgeon's discretion, wound debridement was undertaken, followed by closed drainage (three patients), closed tube irrigation (six patients), and open granulation with delayed plastic surgery (three patients).The incidence of major complications (PMOFR, 22 percent; traditional approach, 92 percent; p = 0.001), intensive care unit readmission (PMOFR, 0 percent; traditional approach, 58 percent; p = 0.005), total hospital length of stay (PMOFR, 32 days; traditional approach, 79 days; p = 0.001), reoperation rates (PMOFR, 0 percent; traditional approach, 100 percent; p = 0.001) and in-hospital 30-day mortality rate (PMOFR, 0 percent; traditional approach, 33 percent; p = 0.05) were superior in the PMOFR group. At a mean follow-up of 2 years, freedom from recurrence of the infection (PMOFR, 100 percent; traditional approach, 11.5 percent; p = 0.005) and overall survival rate (PMOFR, 100 percent; traditional approach, 50 percent; p = 0.005) were also superior with PMOFR. A majority of patients in the PMOFR group (90 percent) had no functional or cosmetic complaints secondary to the procedure.A predetermined plan of immediate debridement followed by treatment with PMOFR rapidly, reliably, and effectively eradicated deep sternal infection. This translated to reduced length of stay and need for additional surgery, improved survival, and excellent intermediate freedom from deep sternal infection, with minimal patient dissatisfaction. The traditional approach to managing deep sternal infection was thus abandoned.     

西安市青年学生胸骨长与身长的关系

本文对1980年测量的西安在校汉族青年学生1585名(男863,女722),年龄16-24岁,按年龄性别分组,计算了身长和胸骨长的均值、胸骨长占身长的百分数、身长与胸骨长的比值、身长、胸骨长指数,并提出了由胸骨长推算身长的回归方程。     

Membrane particle distribution in the sternal epithelia of the terrestrial isopod Porcellio scaber latr. (Crustacea, oniscidea) during CaCO(3) deposit formation and resorption, a freeze-etch analysis.

The anterior sternal epithelium of terrestrial isopods transports cuticular Ca(2+) to and from large sternal CaCO(3) deposits. We analyzed the anterior and posterior sternal epithelium by the means of the freeze-etch technique and measured the size distribution and density of intramembrane particles (IMPs) during three different molting stages. At least three IMP size classes around 4.5, 7.7, and 9.4 nm can be distinguished on the P-face of the apical and basolateral plasma membrane. An additional size class of around 12.8 nm is restricted to the apical compartment. In the anterior sternal epithelium, the density of these large particles changes by a factor of 1.9 during the molt cycle, suggesting a role in CaCO(3) formation and/or resorption. The density of the smaller IMPs rises transiently by a factor of 1.3 in the posterior sternal epithelium only. The IMP density of the basolateral plasma membrane increases significantly by a factor of 1.4 and 1.3 in the anterior and posterior sternal epithelia, respectively. The results indicate that increases in the IMP density contribute to the differentiation to an increased transport activity during the cyclic enlargements of the plasma membrane surface area in the anterior sternal epithelium.     

Superior sternal cleft and minor hemangiomas in a newborn

The association of hemangioma and sternal cleft is rare. It may present as sternal malformation/vascular dysplasia association or PHACES syndrome when associated with other ventral developmental defects. We report on a newborn infant with superior sternal cleft and minor hemangiomas.     

Membrane Particle Distribution in the Sternal Epithelia of the Terrestrial Isopod Porcellio scaber Latr. (Crustacea, Oniscidea) during CaCO3 Deposit Formation and Resorption, a Freeze-Etch Analysis

The anterior sternal epithelium of terrestrial isopods transports cuticular Ca²⁺ to and from large sternal CaCO₃ deposits. We analyzed the anterior and posterior sternal epithelium by the means of the freeze-etch technique and measured the size distribution and density of intramembrane particles (IMPs) during three different molting stages. At least three IMP size classes around 4.5, 7.7, and 9.4 nm can be distinguished on the P-face of the apical and basolateral plasma membrane. An additional size class of around 12.8 nm is restricted to the apical compartment. In the anterior sternal epithelium, the density of these large particles changes by a factor of 1.9 during the molt cycle, suggesting a role in CaCO₃ formation and/or resorption. The density of the smaller IMPs rises transiently by a factor of 1.3 in the posterior sternal epithelium only. The IMP density of the basolateral plasma membrane increases significantly by a factor of 1.4 and 1.3 in the anterior and posterior sternal epithelia, respectively. The results indicate that increases in the IMP density contribute to the differentiation to an increased transport activity during the cyclic enlargements of the plasma membrane surface area in the anterior sternal epithelium.     

The skeletal kinematics of lung ventilation in three basal bird taxa (emu, tinamou, and guinea fowl)

In vivo visceral and skeletal kinematics of lung ventilation was examined using cineradiography in two palaeognaths, the emu (Dromaius novaehollandiae) and the Chilean tinamou (Nothoprocta perdicaria), and a basal neognath, the helmeted guinea fowl (Numida meleagris). Upon inspiration, the thorax expands in all dimensions. The vertebral ribs swing forward and upward, thereby increasing the transverse diameter of the trunk. The consistent location of the parapophysis throughout the dorsal vertebral series, ventral and cranial to the diapophysis, ensures a relatively uniform lateral expansion. An increase in the angle between the vertebral and the sternal ribs causes the sternal ribs to push the sternum ventrally. Owing to the greater length of the caudal sternal ribs, the caudal sternal margin is displaced further ventrally than the cranial sternal margin. When observed in lateral view, sternal movement is not linear, but elliptical. The avian thorax is highly constrained in its movement when compared with crocodylians, the other extant archosaur clade. Birds lack a lumbar region and intermediate ribs. Sternal ribs are completely ossified, and have a bicondylar articulation with the sternum. Considering the importance of pressure differences between cranial and caudal air sac complexes for the generation of unidirectional air flow in the avian lung, it is hypothesized that a decrease in the degrees of freedom of movement of the avian trunk skeleton, greater expansion of the ventrocaudal trunk region, and elliptical sternal movement may represent specific adaptations for fine-tuned control over air flow within the complex avian pulmonary system.     

A rapid, secure method of sternal closure

In 1977 Robicsek(1) described a method of sternal closure that involved a double wire on each side of the sternum, with appropriate circumferential wires. Shortly thereafter, we modified that procedure, as shown in Figure 1. Only one wire is used on each side of the sternum, and fewer circumferential wires are needed. This type of sternal closure can be performed as rapidly as the usual closure of simple circumferential wire sutures and is much more secure, because the circumferential wires cannot cut through the parasternal wire. After using this method in about 100 patients with either poor sternal bone or chronic lung disease, we have encountered no subsequent sternal separation.     

Evolution and functional significance of derived sternal ossification patterns in ornithothoracine birds

The midline pattern of sternal ossification characteristic of the Cretaceous enantiornithine birds is unique among the Ornithodira, the group containing birds, nonavian dinosaurs and pterosaurs. This has been suggested to indicate that Enantiornithes is not the sister group of Ornithuromorpha, the clade that includes living birds and their close relatives, which would imply rampant convergence in many nonsternal features between enantiornithines and ornithuromorphs. However, detailed comparisons reveal greater similarity between neornithine (i.e. crown group bird) and enantiornithine modes of sternal ossification than previously recognized. Furthermore, a new subadult enantiornithine specimen demonstrates that sternal ossification followed a more typically ornithodiran pattern in basal members of the clade. This new specimen, referable to the Pengornithidae, indicates that the unique ossification pattern observed in other juvenile enantiornithines is derived within Enantiornithes. A similar but clearly distinct pattern appears to have evolved in parallel in the ornithuromorph lineage. The atypical mode of sternal ossification in some derived enantiornithines should be regarded as an autapomorphic condition rather than an indication that enantiornithines are not close relatives of ornithuromorphs. Based on what is known about molecular mechanisms for morphogenesis and the possible selective advantages, the parallel shifts to midline ossification that took place in derived enantiornithines and living neognathous birds appear to have been related to the development of a large ventral keel, which is only present in ornithuromorphs and enantiornithines. Midline ossification can serve to medially reinforce the sternum at a relatively early ontogenetic stage, which would have been especially beneficial during the protracted development of the superprecocial Cretaceous enantiornithines.     

The ultrastructure of the sternal gills forming a striking contrast with the coxal gills in a fresh-water amphipod (Crustacea)

Sternomoera yezoensis has specialized sterna with 21 sternal gills in addition to six pairs of coxal gills. Despite a common high permeability to chloride ions, the cpithelia of these two kinds of gills are diametrically opposed in the polarity of the cell membranemitochondria complex. The coxal gill epithelium (4-6 mum thick) is characterized by a welldeveloped AIS (apical infolding system) associated with a huge number of large mitochondria. The AIS exceeds two-thirds of the epithelial thickness and forms a highly sophisticated, subcuticular labyrinth. On the contrary, the sternal gill epithelium, an extension of the sternal epithelium proper, is extremely thick (10-15 mum) and is characterized by a very deep BIS (basolateral infolding system) associated with numerous slender mitochondria. The BIS reaches nine-tenths of the epithelial thickness and forms a giant, baso-lateral labyrinth. Shallower, less elaborate AIS and BIS without mitochondrial association originate from the opposite sides of these epithelia. Although AIS and BIS interpenetrate in the sternal gill epithelium, they never communicate. The results indicate that in addition to the coxal gills, the sterna with Ihe sternal gills function as transporting as well as respiratory organs, though the functional difference between these two kinds of gills remains to be elucidated.     

中国广西晚白垩世一新的巨龙类恐龙

记述了采自广西南宁市郊晚白垩世地层中一巨龙类恐龙新属种:右江清秀龙(Qingxiu- saurus youjiangensis gen.et sp.nov.)。新属种正型标本包括以下不关联的头后骨骼:一段较完整的前部尾椎神经棘、左右胸骨板、左右肱骨。它以以下独特特征组合区别于其他巨龙类:前部尾椎神经棘板状结构不发育、相对较高并呈桨状;胸骨与肱骨最大长之比值较低(约0.65)。广西发现的新属种以及近年来报道的巨龙类恐龙材料表明,亚洲巨龙类恐龙的头后骨骼形态变异度高,白垩纪时期这类恐龙曾在亚洲广为分布。     

Management of sternal wounds with bilateral pectoralis major myocutaneous advancement flaps in 114 consecutively treated patients: refinements in technique and outcomes analysis

Because life-threatening sternal wound complications can occur following sternotomy, the optimal management of sternal wound infections remains an important topic. To decrease morbidity following operative treatment of these patients, the authors made a number of refinements in their treatment protocol over the past several years, particularly with regard to the extent of débridement, method of flap apposition, and management of drains. The purpose of this study was to obtain specific outcomes data by reviewing a large series of patients treated by a single surgeon. In this series of 114 consecutive sternal wounds treated by the senior author (Ascherman), patients were managed almost exclusively with débridement and immediate closure with bilateral pectoralis major myocutaneous advancement flaps. There were no intraoperative deaths. The 30-day perioperative mortality rate was 7.9 percent, with only one death directly related to sternal infection. Nineteen patients (16.7 percent) experienced postoperative morbidity, including partial wound dehiscences (5 percent), skin edge necrosis (5 percent), and seromas (3.5 percent). The authors advocate single-stage management of complicated sternal wounds with immediate débridement and bilateral pectoralis major myocutaneous advancement flaps. The procedure is rapid and effective. Refinements in technique have significantly lowered morbidity.     

X-ray microprobe analysis of epithelial calcium transport

The sternal epithelium of Porcellio scaber was used as a novel model to study the subcellular elemental distribution in control and Ca(2+)-transporting stages in situ. The anterior sternal epithelium (ASE) is specialized for transport of cuticular Ca to sternal CaCO(3) deposits during premolt, and from these deposits during intramolt. The less specialized posterior sternal epithelium transports Ca(2+) to and from the cuticle. In the ASE cells basal [Na], [Cl], and [Mg] are higher than in the apical side. The basal [Na] increases from 105 to 173 mmol/kg dry mass between control and Ca(2+)-transporting stages, accompanied by a decrease in [Cl] and [K]. The [Mg] increases, suggesting transepithelial Mg(2+)-transport. Cytosolic [Ca] varied insignificantly between 4.5 and 5.7 mmol/kg dry mass, however, the number of Ca hot-spots with concentrations between 15 and 50 mmol/kg dry mass increased during transport. Mitochondrial [Ca] decreased in the ASE from 3.3 in the control to 1.0 in the late premolt and to 2.0 mmol/kg dry mass in the intramolt stage. The results suggest Na(+)-dependent mechanisms for transcellular Ca(2+)-transport and the presence of Ca(2+)-binding proteins. Organelles, probably the smooth endoplasmic reticulum, sequester Ca(2+) during intracellular Ca(2+)-transport. A role of mitochondria as a storage site for cuticular Ca is excluded.     

The fine structural organization of sternal glands of pseudergates and workers in termites (Isoptera): a comparative survey

Thirty-nine species belonging to different families of termites are studied to give a comprehensive view of the evolution of the sternal glands. Several modifications occurring at cuticular and cytological levels are described in neuter castes. The outer epicuticle is always pierced by epicuticular pores. In advanced termites the epicuticular filaments greatly increase in number and length creating a thick layer. The pore canals gradually enlarge while the cuticle changes into a lattice structure lining an extracellular space in which the secretion is stored. Two classes of cells are present in basal termites (Mastotermitidae, Hodotermitidae, Termopsidae and Kalotermitidae) but their glandular structures greatly differ between families. A more complex organization with three classes of cells is found in the Serritermitidae and Rhinotermitidae. A regressive evolution occurs in the Termitidae where only two classes of cells are present. A dual nervous control (campaniform sensilla and neurosecretory fibers) is found in lower termites, except for the Hodotermitidae which have mechanosensory bristles. In the other families, neurosecretory fibers are lacking. A comparison with phylogenetic data is given. A more versatile role of sternal glands in neuter castes is hypothesized.     

Sex determination from chest plate roentgenograms

Precise sexing--97% to 99% accuracy--of adult chest plates is possible when highly predictive costal cartilage ossification patterns are combined with four simple metric determinations. More than 1100 chest plate roentgenograms were evaluated for ossification pattern, fourth rib width, corpus width, sternal length and sternal area in an adult decedent population. An elementary, empirically obtained algorithm using the patternings and measurements, along with simple derivations (sternal length and area indices) was developed and then applied in chest plate sexing. This technique is not only easy, rapid and inexpensive, but it also results in a permanent and easily stored record.