Use In Reconstructive Surgery Research Articles

53 Salvage laparoscopic pyeloplasty

Introduction: Greater experience with urological laparoscopy has lead to increasing interest in its use for reconstructive surgery, such as pyeloplasty. We compared the outcomes of primary versus salvage laparoscopic pyeloplasty (LP) in a single surgeon series of 124 LP.Patients and Methods: One hundred and twenty‐four cases of laparoscopic pyeloplasty (LP) were performed, 11 of which followed failed primary treatment at other institutions: balloon dilatation (n = 3); endopyelotomy (n = 3); open pyeloplasty (n = 3); endopyelotomy plus balloon dilatation (n = 1); and open pyeloplasty plus balloon dilatation (n = 1). Nine patients had renal calculi. A four‐port balloon‐dissecting extraperitoneal laparoscopic approach was used in all but one patient who had a horseshoe kidney, necessitating a transperitoneal approach.Results: The operating time was 29 min longer in the secondary pyeloplasty group compared to primary cases (173.3 vs. 144.0 min), but the conversion rate (0% vs. 1.6%) and duration of postoperative hospitalisation (2.5 vs. 2.7 nights) were no greater. The complication rates were 3.6% and 9.1%. The success rates were 98.2% and 90.9% (P = 0.63) at a mean follow‐up of 20.2 and 19.7 months.Conclusion: Extraperitoneal laparoscopic dismembered pyeloplasty is capable of addressing all causes of UPJ obstruction with excellent functional results and low morbidity, and in an operating time similar to that of open pyeloplasty. Secondary LP does not increase hospitalization, conversion or complication rates.

Design and assessment of a tissue‐engineered model of human phalanges and a small joint

To develop models of human phalanges and small joints by suturing different cell-polymer constructs that are then implanted in athymic (nude) mice. Models consisted of bovine periosteum, cartilage, and/or tendon cells seeded onto biodegradable polymer scaffolds of either polyglycolic acid (PGA) or copolymers of PGA and poly-L-lactic acid (PLLA) or poly-epsilon-caprolactone (PCL) and PLLA. Constructs were fabricated to produce a distal phalanx, middle phalanx, or distal interphalangeal joint. Studies of more than 250 harvested implants were conducted at the Northeastern Ohio Universities College of Medicine. Polymer scaffold, cell type, and implantation time were examined. Tissue-engineered specimens were characterized by histology, transmission electron microscopy, in situ hybridization, laser capture microdissection and qualitative and quantitative polymerase chain reaction analysis, magnetic resonance microscopy, and X-ray microtomography. Over periods to 60 weeks of implantation, constructs developed through vascularity from host mice; formed new cartilage, bone, and/or tendon; expressed characteristic genes of bovine origin, including type I, II and X collagen, osteopontin, aggrecan, biglycan, and bone sialoprotein; secreted corresponding proteins; responded to applied mechanical stimuli; and maintained shapes of human phalanges with small joints. Results give insight into construct processes of tissue regeneration and development and suggest more complete tissue-engineered cartilage, bone, and tendon models. These should have significant future scientific and clinical applications in medicine, including their use in plastic surgery, orthopaedics, craniofacial reconstruction, and teratology.

Formal Decision Trees in Plastic Surgery

Formal Decision Trees in Plastic Surgery

Expression pattern of the chromosome 21 transcription factor Ets2 in cell‐seeded three‐dimensional bone constructs

The ability to generate new bone for reconstructive surgery use is a major clinical need. Tissue engineering with osteoprogenitor cells isolated from the patient's periosteum and seeded into bioresorbable scaffolds offers a promising approach to the generation of skeletal tissue. To our knowledge, there is no description about the expression of Ets2 in tissue engineered "bone neotissue." The aim of our study was to manufacture cell-seeded three-dimensional bone constructs with human periosteal cells on poly (lactic-co-glycolic acid) polymer fleeces to describe the expression pattern of Ets2 and its target genes osteocalcin and osteopontin; expression analysis of type I collagen, core-binding factor-1, alkaline phosphatase, and osteonectin; the ability of matrix mineralization and ALP enzymatic activity showed the osteogenic character of the constructs. A significant correlation between the expression of Ets2 and osteopontin mRNA (r = -0.70; p < 0.05) could be shown. A 1.35-fold increase of Ets2 expression from days 1 to 9 was detected, followed by a slight decrease from days 11 to 15. Until the end of the culture period, the expression of Ets2 reached a comparable high level as detected on day 9. In contrast, the expression level of osteopontin mRNA reached a maximum at day 7, followed by a progressive 3.04-fold decrease until day 21. This study shows for the first time that Ets2 gene and its transcriptional target genes are expressed in tissue-engineered bone constructs. These findings have the potential to provide much-needed information about the role and function of Ets2 in human osteogenesis processes and creation of "bone neotissue."

Early Postoperative Efficacy of Fibrin Glue in Face Lifts: A Prospective Randomized Trial

Fibrin glue is increasingly finding use in plastic surgery at the clinical and basic science level. The authors conducted a prospective, nonblinded, randomized, controlled trial in 30 patients undergoing face lifts to examine the efficacy of fibrin glue in reducing postoperative wound drainage, hematomas, and, in particular, the degree of ecchymosis and edema at 24 hours and at 8 days. Patients were their own controls and were randomized to have the glue on one side of their face only to compare the glued and unglued sides. The patients ranged in age from 42 to 72 years (mean age, 60 years). There was one major hematoma requiring surgical evacuation. In the remaining 29 patients, the mean drainage on the glued side was 26 ml, compared with 33.5 ml on the control, unglued side. This difference was statistically significant numerically (p = 0.037) but was not thought to be surgically significant. Comparing scores among grades of hematomas, ecchymosis, and edema, there were minimal differences between the glued and unglued sides. This study suggests that fibrin glue may not be as beneficial as previously thought in reducing ecchymosis and edema in the early postoperative period after face lifts, and its future role is discussed.

Search for ideal biomaterials to cultivate human osteoblast-like cells for reconstructive surgery

In this study we cultured human osteoblast-like cells on 16 different biomaterials to find an optimal biomaterial for subsequent use in reconstructive surgery. The tested biomaterials can be divided into five groups: collagen-based membranes of bovine, equine or calf origin, tricalcium phosphate based membranes (alpha and beta), hyaluronic acid based, anorganic bovine bone and anorganic silicone-based membranes. Cell proliferation and cell colonization (Environmental Scanning Electron Microscope, ESEM) analysis were performed. The results of the study demonstrated that four of the examined biomaterial/cell constructs showed a very good proliferation rate and cell density: No. 3 (Tissue Vlies), No. 7 (Sepra film), No. 16 (Biobrane) and No. 17 (Biomend). No favourable group of biomaterials was noticeable. Moreover, the results indicate that these four biomaterials as a part of bone constructs are the best tools for engineering new bone tissue. In contrast, biomaterials No. 19a (Bio-Oss) and 19b (Bio-Oss Collagen) showed the lowest proliferation rates. The result of No. 19b was improved by treatment in the perfusion chamber for 48 h as well as by additional use of vacuum. The present study is an important base for further analysis of biomaterials and consequently for the development of tissue engineering.

EXTRAPERITONEAL LAPAROSCOPIC PYELOPLASTY FOR PRIMARY AND SECONDARY URETEROPELVIC JUNCTION OBSTRUCTION

Greater experience with urological laparoscopy has lead to increasing interest in its use for reconstructive surgery, such as pyeloplasty. A total of 124 cases of laparoscopic pyeloplasty were performed, of which 11 followed failed primary treatment done elsewhere, namely balloon dilation (3), endopyelotomy (3); open pyeloplasty (3), endopyelotomy plus balloon dilation (1) and open pyeloplasty plus balloon dilation (1). Nine patients had renal calculi. A 4 port, balloon dissecting, extraperitoneal laparoscopic approach was used in all except 1 patient, who had a horseshoe kidney, necessitating a transperitoneal approach. Operative time was 29 minutes longer in the secondary pyeloplasty group compared to primary cases (173.3 vs 144.0 minutes) but the conversion rate (0% vs 1.6%) and duration of postoperative hospitalization (2.8 nights each) were no greater. The complication rate was 3.6% and 9.1%, respectively. The success rate was 98.2% and 90.9% (p = 0.63) at a mean followup of 20.2 and 19.7 months, respectively. In the 9 patients with renal calculi a total of 18 calculi (94.7%) were successfully removed and the ureter was transposed medial to a crossing vessel in 50.0%. Trainee operating did not significantly prolong the procedure vs no training (162.0 vs 143.9 minutes, p = 0.06). Extraperitoneal laparoscopic dismembered pyeloplasty is capable of addressing all causes of ureteropelvic junction obstruction with excellent functional results and low morbidity, and with an operative time similar to that of open pyeloplasty. Secondary laparoscopic pyeloplasty does not increase hospitalization, conversion or complication rates.

Cultivation of human tenocytes in high-density culture

Limited supplies of tendon tissue for use in reconstructive surgery require development of phenotypically stable tenocytes cultivated in vitro. Tenocytes in monolayer culture display an unstable phenotype and tend to dedifferentiate, but those in three-dimensional culture may remain phenotypically and functionally differentiated. In this study we established a three-dimensional high-density culture system for cultivation of human tenocytes for tissue engineering. Human tenocytes were expanded in monolayer culture before transfer to high-density culture. The synthesis of major extracellular matrix proteins and the ultrastructural morphology of the three-dimensional cultures were investigated for up to 2 weeks by electron microscopy, immunohistochemistry, immunoblotting and quantitative, real-time PCR. Differentiated tenocytes were able to survive over a period of 14 days in high-density culture. During the culture period tenocytes exhibited a typical tenocyte morphology embedded in an extensive extracellular matrix containing cross-striated collagen type I fibrils and proteoglycans. Moreover, expression of the tendon-specific marker scleraxis underlined the tenocytic identity of these cells. Taken together, we conclude that the three-dimensional high-density cultures may be useful as a new approach for obtaining differentiated tenocytes for autologous tenocyte transplantation to support tendon and ligament healing and to investigate the effect of tendon-affecting agents on tendon in vitro.

Update on new biomaterials and their use in reconstructive surgery.

Craniofacial reconstruction may be limited by the paucity of autologous materials available and donor site morbidity. Recent advances in the development of biomaterials have given the reconstructive surgeon new options for restoring form and function. There are now biomaterials (second generation) that can elicit a controlled action and reaction to the surrounding tissue environment (bioactive), and those that can exhibit a controlled chemical breakdown and resorption, with ultimate replacement by regenerating tissue (resorbable). Third-generation biomaterials are being designed to stimulate regeneration of living tissues using tissue engineering and in situ tissue regeneration methods. These techniques will lead to limitless possibilities for tissue regeneration and repair. At present, biomaterials that may find future use in craniofacial reconstruction include newly developed bone and skin substitutes and soft-tissue fillers.

Triple valve repair for young rheumatic patients.

Facing young foreign polyvalvular rheumatic patients, for which long-term anticoagulation is not available, we have chosen to attempt triple valve repair procedures in order to avoid prosthetic implantation in this particular population suffering from triple valve disease. Twenty-one young rheumatic patients (mean age:11+/-4 years) underwent triple valve repair procedures including cusp extension on the aortic valve aortic between September, 1992 and December, 2000. Valvular pathology characteristics according to Carpentier's classification included mitral insufficiency type III post+II ant (n=10), type III post (n=4), type II ant (n=2), mitral stenosis (n=5), type III aortic insufficiency (n=21), type I (n=13) and type III (n=8) tricuspid insufficiency. Firstly, the mitral valve disease were corrected using Carpentier's techniques of repair: prosthetic ring annuloplasty (n=16), commissurotomy (n=12), chord transposition (n=11) or shortening (n=4), papillary muscle sliding plasty (n=4) and pericardial patch leaflet enlargement (n=6). Secondly, aortic lesions were corrected using glutaraldehyde stabilized autologous pericardium triple cusps extension technique (n=21). Lastly, tricuspid repairs were always performed on beating hearts using commissurotomy (n=8), prosthetic ring (n=12) or other techniques (n=9) of annuloplasty. The operative mortality was 4.7% (one patient died). Echocardiograms before discharge showed grade I mitral insufficiency in seven patients and grade I aortic insufficiency in five patients. There was no late death during a mean follow-up of 51+/-31 months. Two patients underwent valvular redo surgery because of aortic and mitral plasty deterioration due to rheumatic disease progress. After 5 years, 90% of the patients were free from redo valvular surgery. In rheumatic patients, autologous pericardial patch extension of the aortic valve permitted widespread use of reconstructive surgery even in patients suffering from triple valve disease. Triple valve repair, in this particular challenging setting of patients, has provided satisfactory initial and mid-term results and could be considered as an interesting palliative surgical approach.

Surgical anatomy of the gluteal region's subcutaneous screen and its use in plastic surgery.

The surgical anatomy of the subcutaneous screen on the gluteal region has aroused the interest of plastic surgeons because of the increasing search for surgical procedures that determine an improvement of its form. The dissection of 60 fixed surgical pieces showed the presence of a Buttocks' Sustaining Aparell formed by a trabecular conjunctival mesh termed main and secondary in a "beehive" aspect which may possibly be important in the maintenance of the buttock's characteristic contour. The planned implication of the Sustaining Aparell may determine, through an observation of its structure, a flattening or a ptosis of the gluteal region, allowing a better understanding of the aesthetic of this region.

A dual wavelength spectrophotometer for use in plastic surgery. Comparison with a Hamamatsu NIRO-500 instrument.

The use of free flaps is well established in plastic and reconstructive surgery. However, some 10% of free flaps fail in the first 48 postoperative hours. Of these flaps 83% can be saved with immediate surgical intervention (Furnas and Rosen, 1991). A monitor of tissue viability is therefore required which should be continuous, easily interpreted and should reliably indicate changes in flap perfusion, particularly venous ischaemia which has been shown to be the most detrimental to rate of survival and area of survival of both skin and myocutaneous flaps (Thorniley et al., 1998). It should also, ideally, distinguish venous ischaemia from that caused by arterial or total occlusion. Recent studies have shown near infrared spectroscopy to satisfy many of these requirements as a monitor of flap perfusion (Irwin et al., 1995; Thorniley et al., 1998). However this technique, intended as it is for cerebral monitoring, is over-specified and more expensive than is necessary for our needs. The aim of this work is to compare our new device with NIRS using standard occlusion tests to establish whether this device can distinguish venous from total occlusions as effectively as a commercial NIRS device. Dual wavelength near-infrared instruments have been in use for some time in a variety of applications (Mancini et al., 1991; Chance et al, 1992; Chance, 1994). Our device differs in the use of an inexpensive, readily available dual light source from a pulse oximeter probe and signal processing by a “Lab View virtual instrument” residing on a laptop computer. The resulting instrument is small, easily portable and can use a miniature, sterilisable probe suitable for clinical use.KeywordsFree FlapTotal OcclusionRadial Forearm FlapRoyal London HospitalPulse Oximeter ProbeThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Strategies for cell engineering in tissue repair

Cellular and tissue engineering are new areas of research, currently attracting considerable interest because of the remarkable potential they have for clinical application. Some claims have indeed been dramatic, including the possibility of growing complete, artificial organs, such as the liver. However, amid such long-term aspirations there is the very real possibility that small tissues (artificial grafts) may be fabricated in the near future for use in reconstructive surgery. Logically, we should focus on how it is possible to produce modest, engineered tissues for tissue repair. It is evident that strategies to date either depend on innate information within implanted cells, to reform the target tissue or aim to provide appropriate environmental cues or guidance to direct cell behavior. It is argued here that present knowledge of tissue repair biology points us toward the latter approach, providing external cues which will direct how cells should organize the new tissue. This will be particularly true where we need to reproduce microscopic and ultrastructural features of the original tissue architecture. A number of such cues have been identified, and methods are already available, including substrate chemistry, substrate contact guidance, mechanical loading, and biochemical mediators to provide these cues. Examples of these are already being used with some success to control the formation of tissue structures.

Plastic Surgery’s Plastics

Alloplastic materials have become an essential part of reconstructing the craniofacial skeleton. This article reviews several of the more commonly used implant materials and summarizes their mechanical properties and use in reconstructive surgery.

Laparoscopically Harvested Omental Free Flap to Cover a Large Soft Tissue Defect

The omentum has been a very important tool in the armamentarium of the reconstructive surgeon. It has lost much of its value because of the morbidity associated with laparotomy. Laparoscopic surgery has become a popular technique and allows operations to be performed with minimal morbidity. The possibility of harvesting the omental free flap with the laparoscope and its use in reconstructive surgery has been demonstrated. Since the first laparoscopic cholecystectomy was performed, many surgeons have learned the procedure. Other surgical specialties have also benefited from this technique. The omentum provides a large amount of vascularized tissue and excellent wound coverage. It can be transferred as a pedicle flap, or as a free flap, using microvascular technique. The procedure was developed and refined in an animal model. One team harvested the omentum with laparoscopic assistance, while the other team prepared the recipient vessels. After completion of the microvascular transfer, the dogs were observed for 14 days. At that time, the omental tissue was examined for gross and histologic changes. A clinical case is also presented. Gross and microscopic studies documented the viability of this approach. The patient tolerated the procedure well and had an unremarkable postoperative course. Experimental and clinical evidence shows that the omentum can be successfully harvested as a free flap using laparoscopic assistance. This technique may prove to be of clinical significance and very useful for reconstructive surgery with less morbidity.

Reaction to Intraarticular Allografts Sterilized with Ethylene Oxide

Allografts represent an alternative to autogenous tissue for use in reconstructive surgery of the anterior cruciate ligament (ACL). There are many issues for the surgeon to consider when using these tissues. Among these issues is the effect of processing protocols used by the tissue bank supplying the allografts. Ethylene oxide-sterilized allografts for ACL reconstruction have been reported to be associated with an intraarticular reaction. This reaction has been characterized by a persistent effusion and graft fragmentation requiring removal of the graft. It has been suggested that two byproducts of ethylene oxide sterilization, ethylene chlorohydrin (EC) and ethylene glycol (EG), are possibly responsible for these reactions. Studies attempting to elicit this intraarticular reaction as seen in humans using a rabbit model were unsuccessful. These animal-model studies included intraarticular injections of solutions of EC and EG, ethylene oxide-sterilized patellar tendon particulates, and ACL reconstruction using ethylene oxide-sterilized patellar tendon. The intraarticular reactions described in this article have not been reported because most tissue banks now procure soft tissues aseptically and no longer sterilize them with ethylene oxide for use in transplantation.

Synthesis of human cartilage using organotypic cell culture.

The limited supply of fresh autologous cartilage tissue for use in reconstructive surgery necessitates the use of vital banked allografts. A feasible in vitro production of cartilage tissue composed of living cells requires the use of modern tissue culture techniques retaining the phenotypic characteristics of chondrocytes. With this purpose in mind, human chondrocytes were isolated and cultured using different culture procedures: monolayer, suspension and agar gel. The differentiation state of chondrocytes as well as proteoglycan and collagen syntheses were assessed by histochemical and immunohistochemical methods. Whereas chondrocytes in monolayer displayed an unstable phenotype and tended to dedifferentiate, in three-dimensional culture the chondrocytes remained morphologically, phenotypically and functionally differentiated. Furthermore, an accumulation of matrix products pericellularly was observed in the agar gel. The results suggest that three-dimensional cultures in agar gel may allow the in vitro production of bioartificial cartilage for transplantation.

Accelerated endochondral osteoinduction in the absence of bone matrix particles in a rat model system

Ethanol-precipitated proteins obtained from demineralized rat bone powder (DBP) by 4M guanidine-HCl extraction have been shown to reproducibly induce ectopic endochondral bone formation when subcutaneously implanted in rats in the absence of bone matrix particles. Histologic and biochemical analysis revealed a temporal sequence of chondrocyte differentiation, calcified cartilage formation, neovascularization, osteoblast differentiation, bone formation, osteoclastic bone remodeling, and hematopoietic marrow development that is complete by 21 days. In contrast to previous reports, these results clearly show an osteoinductive response independent of the presence of insoluble extracellular bone matrix. Compared with conventional DBP implants, the guanidine-extractable protein (GE) produces an accelerated and more robust osteoinductive response. Histologically, the initial chondrogenic response at days 6 to 9 is greatly amplified. Alkaline phosphatase specific activity peaks at day 9, several days earlier than for DBP, and is sixfold higher. Calcium accumulation in GE implants at day 12 is fivefold greater than with DBP, and all mineral is localized within the matrix of newly calcified cartilage and new bone. Osteoclasts are up to ninefold more abundant in the rapidly remodeling GE ossicle, making space for hematopoietic marrow. Delivery of GE coprecipitated with inert bone matrix particles was also more effective than DBP, although the response was somewhat attenuated compared with GE alone. Bony filling of 4-mm defects in rat mandibular rami was elicited by 10 mg of GE and followed an endochondral process with increased neovascularization compared with DBP and unimplanted controls. This guanidine-extractable protein fraction should prove useful for inducing quantities of chondrocytes and osteoclasts for in vitro study, and for analysis of osteoinductive requirements. Likewise, ethanol-precipitated osteoinductive proteins implanted alone or with carrier particles hold promise for use in reconstructive surgery.

Dimethylsulfoxide (DMSO) for human single-stage intraoperative tissue expansion and circulatory enhancement

Dimethylsulfoxide (DMSO) has been in clinical use since the early 1960s. In 1967 the discovery that DMSO can greatly reduce ischemia in experimental pedicle flaps stimulated its use in plastic surgery by the authors since 1976. In 1987 its ability to soften collagen, thus permitting degrees of immediate intraoperative tissue expansion hitherto unknown, was applied clinically for the first time. Evolving use of topical 70% DMSO alone, in combination with intravenous DMSO, and intravenous DMSO alone with greater efficacy is discussed. Cases of intraoperative tissue expansion for large lesion excision and use in abdominoplasty to maximize skin resection are discussed. In breast reconstruction, maximal tissue expansion in minutes with immediate placement of large permanent prostheses ends the delay of reconstruction and problems of chronic tissue expander capsule formation and gives this technique a clear advantage over other reconstructive techniques.

Fasciocutaneous Flaps and Their Use in Reconstructive Surgery

Fasciocutaneous Flaps and Their Use in Reconstructive Surgery