Colored Latex Research Articles

Arterial Blood Supply of the Stifle Joint in Horses.

The vascularization pattern of the equine stifle joint is insufficiently described in the literature, even though there is a growing need for knowledge of the exact blood supply, as (i) arthroscopy and endoscopic surgery techniques are increasingly performed in horses and (ii) ex vivo models of menisci need nutrient supply that mimic the in vivo situation. The aim of this study was to describe the vessels involved in the stifle joint supply and the exact branching pattern of the popliteal artery. Colored latex was injected into the arteries of nine pelvic limbs of equine cadavers (n = 6) to evaluate the occurrences, variations and approximate diameters of vessels that supplied the stifle joints. Next to a branch of the saphenous and descending genicular arteries, eleven branches of the popliteal artery could be described in horses that feed the vascular network of the stifle joint. With a focus on the blood supply of the menisci, a vascularization map was created to show the main influx to these intra-articular structures in detail. These findings are potentially of great importance to both clinicians in preparation of best-suited incisions for arthroscopy and researchers designing new approaches for meniscal studies and choosing suitable animal models.

Ink-Jet Printing of Colored Latex Inks with a “Soft” Core–“Hard” Shell Structure

Colored latex particles (CLPs) as a novel colorant have been widely applied to salt-free dyeing and printing due to their adjustable composition, brilliant colors, excellent durability, and small particle size. In this paper, the effects of glass-transition temperatures (Tg) on the filterability of CLP inks were first studied, and the results showed that the CLP inks can be successfully filtered and ejected when the Tg’s of CLP inks exceeded 48 °C. Based on our previous research, CLP (Tg = 25 °C)-printed fabrics had excellent color fastness and a soft hand feel, while a stiff hand feel occurred with the increase of the Tg. Herein, the CLPs with a core–shell structure (CLP@PS) were designed using CLPs (Tg = 25 °C) as a “soft” core for ensuring the color fastness of printed fabrics and PS as a “hard” core for ensuring excellent filterability of inks. Transmission electron microscopy and dynamic light scattering indicated that the prepared particles had an obvious core–shell structure, and the particle size was 96 nm. To balance the filterability of inks and color fastness of printed fabrics, the encapsulated thickness was optimized at 20 nm by adjusting the amounts of styrene (St) and 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AIBA). The flow rate and filtration time of CLP@PS inks were 8.9 mL/s, and 11 s, respectively. Finally, the CLP@PS inks were applied to ink-jet printing of cotton fabric. Compared with pigment ink-jet printing, CLP@PS-printed fabrics had a softer hand feel and better rubbing and washing fastness.

An Anatomic Assessment of the Intercavernous Sinuses and Review of the Literature.

Introduction As expanded endoscopic endonasal approaches are gaining popularity, a thorough understanding of the anatomy of the intercavernous sinuses is pertinent to avoid bleeding complications. There have been few studies reporting the presence and dimensions of the anterior intercavernous sinus (AIS), posterior intercavernous sinus (PIS), and inferior intercavernous sinus (IIS). We performed a cadaveric study to better understand these structures. Methods Colored latex was injected into the arterial and venous trees of 17 cadaveric heads. Dissections assessed the presence and dimensions of the AIS, PIS, and IIS. In an additional three specimens, the sellar contents were subjected to histological analysis. Results Of the 20 total specimens, 13 (65%) demonstrated the gross presence of all three sinuses. In six specimens (30%), only the AIS and PIS could be identified, and in one specimen, only an AIS and IIS were identified. An AIS was identified in all 20 (100%) specimens, PIS in 18 (88%), and an IIS in 14 (70%). In two specimens (10%), the AIS covered the entire face of the sella. Dimensions of the AIS averaged 1.7 × 11.7 × 2.8 mm, PIS averaged 1.5 × 10.8 × 1.7 mm, and IIS averaged 8.7 × 11.8 × 1.0 mm when present. Conclusion All examined specimens demonstrated the presence of an AIS, and most had a PIS. The presence of an IIS was more variable. Preoperative awareness of these sinuses is helpful in planning transsphenoidal surgery to minimize the risk of bleeding.

Ultrasound visualization of the thumb annular pulleys: A cadaveric validation study.

The thumb annular pulley system is unique from the other digits and is integral to normal thumb function. Injuries to this pulley system can present a diagnostic challenge. No prior study has evaluated the ability of ultrasound (US) to evaluate all four thumb pulleys. To validate the sonographic visualization of all four thumb pulleys. Prospective cadaveric laboratory investigation. Academic center procedural skills laboratory. Twelve unembalmed cadaveric hands from seven adult male donors ages 78-89 years with body mass index 21.9-26.6kg/m2 . Based on anatomic descriptions, a single examiner used a standardized protocol and high-frequency linear transducers to identify the A1, variable (Av), oblique (Ao), and A2 pulleys of the thumb in 10 cadaveric hands. As part of the validation process, the presumed Ao pulley was injected with diluted colored latex using US guidance. Two additional cadaveric specimens were dissected for detailed study of the thumb pulley system. Correlation between the four anatomic pulleys as revealed by dissection and the US findings, including identification of latex location with respect to the Ao pulley. US correctly identified all four thumb pulleys as distinct anatomic structures and the sonographic appearance of the pulleys correlated with the dissection in all 10 specimens. Latex was observed in the Ao pulley in 100% of the cadavers. Ultrasound can be used to accurately identify all four thumb pulleys, including distinct Ao and Av pulleys, and should be considered in the evaluation of thumb pulley injuries. This is the first study to validate the US visualization of the annular pulley system of the thumb.

Preparation of Covalent and Solvent-resistance Colored Latex Particles and Its Application on Cotton Fabric

Conventional colored latex particles have poor solvent resistance due to the absence of chemical bonds between the dye and polymer component, resulting in staining and greatly restricting its application. In this research, the disperse dye was chemically bonded to the polymer to prepare covalent and solvent-resistance colored latex particles. Firstly, C.I. Disperse Red 60, as a common disperse dye in industry, was modified by acryloyl chloride (amidation reaction) for the purpose of introducing the C=C bonds. The structure of modified C.I. Disperse Red 60 was confirmed by 1HNMR, FTIR and elemental analysis and its spectral property was also evaluated. Then the covalent colored latex particles were synthesized via miniemulsion copolymerization of styrene (St) and ethyl acrylate (EA) in presence of modified C.I. Disperse Red 60 monomer. Results of FTIR, TG, DSC and TEM indicated that the covalent colored latex particles were successfully prepared. By using UV-spectroscopy, the solvent resistance of the colored latex membranes in petroleum ether, hexane, cyclohexane, and ethanol was monitored, respectively. Slight change of the absorption was detected for 10 days, which verified the excellent solvent resistance of covalent colored latex membranes. Finally, the prepared colored latex particles were applied on cotton printing in the absence of binder. The results showed that the colored latex particles printed fabric had superior rubbing fastness and soft hand feel.

Development of a New Large-Animal Model for Composite Face and Whole-Eye Transplantation: A Novel Application for Anatomical Mapping Using Indocyanine Green and Liquid Latex.

Recent advances in the field of vascularized composite allotransplantation have revolutionized reconstructive surgery and demonstrated opportunity for restoration of orbital content and perhaps vision. The development of an animal model that would facilitate study of surgical technique, nerve regeneration, vision restoration, and immunosuppression is needed. The aim of this study is to describe three different large-animal cadaveric models suitable for composite face and whole-eye transplantation. In addition, the authors introduce a novel colored liquid latex and indocyanine green mixture for vasculature identification and visualization. The authors studied three different flap designs using cadaveric Yorkshire swine and modified them for face and whole-eye transplant harvest. Flaps harvested included a chimeric flap, a monobloc flap, and a bipedicled free flap. The authors injected selected vasculature with colored latex to better delineate vascular anatomy supplying the orbit and face. Indocyanine green was added to the latex solution to allow for visualization of the vascular supply using near-infrared imaging. Colored latex and indocyanine green injections were successfully visualized in all cadaveric dissections. All three modified flap designs showed a well-defined and consistent vascular network within each face and whole-eye transplantation flap using laser-assisted near-infrared imaging. The authors present the feasibility of composite face and whole-eye transplantation models using a novel mixture of liquid latex and indocyanine green in a porcine cadaver. Further study in large animals is needed to appraise the surgical feasibility of this procedure and potential for clinically relevant outcomes, including vision restoration. The authors believe this study establishes a foundation for translation into live animal models for optic nerve regeneration.

A Multiplex Immunochromatographic Assay Employing Colored Latex Beads for Simultaneously Quantitative Detection of Four Nitrofuran Metabolites in Animal-Derived Food

A rapid and sensitive high-throughput latex bead immunochromatographic assay (LB-ICA) for simultaneously quantitative detection of four major nitrofuran metabolites, including semicarbazide (SEM), 1-aminohydantoin (AHD), 3-amino-5-methylmorpholino-2-oxazolidinone (AMOZ), and 3-amino-2-oxazolidinone (AOZ) in animal-derived food (chicken, fish, and shrimp) was developed. Four different coating antigens were separately immobilized on nitrocellulose (NC) membrane as capture reagents; red latex beads were sprayed as constant control line. Specific monoclonal antibodies labeled with blue- or red-colored latex bead reacted with analytes in standard or sample and flowed along the strip, exhibiting visible and colorful test lines after unbound antibodies coupled with corresponding antigens on four test lines. No mutual interference was found in the simultaneous detection of the four analytes even at concentrations (100 μg L−1) higher than their respective cutoff values. The limits of detection (LODs) for SEM, AHD, AMOZ, and AOZ were 0.02–0.1 μg kg−1 in chicken, 0.02–0.15 μg kg−1 in fish, and 0.03–0.12 μg kg−1 in shrimp, respectively. Recoveries ranged from 73.5 to 109.2% at fortified concentration of LOD, 2LOD, and 4LOD, with coefficient of variation < 15%. Analysis of field animal-derived food samples by LB-ICA was in accordance with that of LC-MS/MS. Therefore, this proposed multiplex LB-ICA was a promising method for on-site screening of multiple analytes in animal-derived food.

Re-defining the anatomical structures for blocking the nerves in adductor canal and sciatic nerve through the same injection site: an anatomical study.

The aim of this study is to re-define the anatomical structures which are important for blocking the sciatic nerve and the nerves within the adductor canal which innervate the knee joint through the same injection site. We also aimed to investigate the spread of the anesthetic toward the areas in which the mentioned nerves lie on cadavers. This study was performed on 16 lower extremities of formaldehyde-embalmed eight adult cadavers. The anatomy of adductor canal, courses of the nerves within the canal and the relationships of the saphenous, medial femoral cutaneous, medial retinacular, posterior branch of the obturator and sciatic nerves with each other and with the fascial compartments were investigated. Transverse sections that crossed the superior border of vastoadductor membrane were taken to reach the sciatic nerve in the shortest way. Colored latex was injected to demonstrate the anesthetic blockage of the targeted nerves. The structures along the needle's way were investigated. The saphenous, medial femoral cutaneous and at its distal part posterior branch of the obturator nerve were colored with latex within the adductor canal. The nerve to vastus medialis (in other words, the medial retinacular nerve) lay beneath the fascia of vastus medialis and did not enter the adductor canal. There was a fascial plane which did not allow the passage of colored latex toward the sciatic nerve. To traverse this fascial structure, it was found out to be necessary to insert the needle perpendicular to both the vertical and transverse axes of the thigh and then advance it along 2/3 of diameter of the thigh. Thus, the colored latex was observed to fill the compartment where the sciatic nerve lay within. Blocking the sciatic nerve and the nerves within the adductor canal which innervate the knee joint through the same injection site seems anatomically possible without injuring any neurovascular structures.

Sonographic and Anatomic Description of the Subtalar Joint

Our study provides a detailed anatomic and sonographic description of the subtalar joint, a single joint that, anatomically, is divided into the anterior subtalar joint (ASTJ) and the posterior subtalar joint (PSTJ). Cadaver specimens of the ankle and foot were examined in detail by ultrasound (US), and the subtalar joints of all the specimens were injected with colored latex of a contrasting color under US guidance. Compatible with other studies, examination of the sections revealed lack of communication between the ASTJ and the PSTJ and communication between the PSTJ and the posterior recess of the tibiotalar joint. A recommended list of standardized ultrasound scans was developed using a Delphi consensus process, which allows sonographers to evaluate both the ASTJ and PSTJ from the medial, lateral and posterior aspects. The recommended ultrasound scans were found to be applicable based on a test of agreement between images acquired in cadaver specimens and images acquired in four centers using healthy patients.

Ultrasound-Guided Posterior Femoral Cutaneous Nerve Block: A Cadaveric Study.

To identify any anatomic barriers to local anesthetic spread between the sciatic nerve (SN) and the posterior femoral cutaneous nerve (PFCN) at the level of the infragluteal crease and to describe a potential technique for an ultrasound (US)-guided subgluteal PFCN block in a cadaveric model. Bilateral US-guided subgluteal injections of a colored latex solution were performed around the SN (15 mL) and PFCN (10 mL) in 4 unembalmed cadavers, for a total of 8 cadaver thighs. The specimens were dissected after latex polymerization to observe the spread of the latex solutions. With US guidance, the PFCN was visualized deep to the gluteus maximus and slightly superficial or lateral to the SN at the level of the infragluteal crease. The SN and PFCN were found on dissection to be coated with their respective colored latex in all 8 thighs. The SN and PFCN were consistently separated by the deep investing muscular fascia of the thigh, with only 2 thighs showing substantial mixing of latex injectates. The deep investing muscular fascia of the thigh appears to impede the spread of injectate between the SN and PFCN in a most unembalmed cadaver specimens. A US-guided subgluteal PFCN blockade may be a feasible technique to complement an SN block when complete anesthesia of the posterior thigh is required.

Variability and reliability of the vastus lateralis muscle anatomy

Purpose: The aims of this study are to investigate the variability of the morphological and neurovascular anatomy of the vastus lateralis (VL) muscle and to describe the relationships among its intramuscular partitions and with the other muscles of the quadriceps femoris. Clinical implications in its reliability as a flap donor are also discussed.Methods: In 2012, the extra- and intramuscular neurovascular anatomy of the VL was investigated in 10 cadaveric lower limbs. In three specimens, the segmental arterial pedicles were injected with latex of different colors to point out their anastomotic connections. The morphological anatomy was investigated with regard to the mutual relationship of the three muscular partitions and the relation of the VL with the other muscles of the quadriceps femoris.Results: The VL has a segmental morphological anatomy. However, the fibers of its three partitions interconnect individually and with the other bellies of the quadriceps femoris, particularly, in several variable portions with the vastus intermedius and mainly in the posterior part of the VL. The lateral circumflex femoral artery and its branches have variable origin, but demonstrate constant segmental distribution. Intramuscular dissection and colored latex injections show a rich anastomotic vascular network among the three partitions.Conclusions: Moderate variability exists in both the myological and the neurovascular anatomy of the VL. Despite this variability, the anatomy of the VL always has a constant segmental pattern, which makes the VL a reliable flap donor. Detailed knowledge of the VL anatomy could have useful applications in a broad clinical field.

Sonographic Visualization of Thenar Motor Branch of the Median Nerve: A Cadaveric Validation Study

BackgroundThe thenar motor branch (TMB) of the median nerve may be affected in carpal tunnel syndrome and can be injured during carpal tunnel surgery. Although ultrasound has been used to identify small nerves throughout the body, the sonographic evaluation of the TMB has not been investigated formally. ObjectiveTo document the ability of ultrasound to visualize the TMB of the median nerve in an unembalmed cadaveric model. DesignProspective laboratory investigation. SettingProcedural skills laboratory at a tertiary medical center. MethodsOn the basis of anatomical descriptions, dissection and clinical experience, a technique was developed to sonographically identify the presumed TMB of the median nerve at the distal carpal tunnel. A single, experienced examiner then identified the presumed TMB in 10 unembalmed, cadaveric upper limb specimens (4 right, 6 left) obtained from 9 donors (4 male, 5 female) ages 76-85 years with body mass indices of 18.2-29.5 kg/m2 with both 12-3 MHZ and 16-7 MHz linear array transducers. The same examiner then injected 0.2-0.3 mL of diluted colored latex into and around the presumed TMB using direct ultrasound guidance. At a minimum of 24 hours postinjection, specimens were dissected under loupe magnification to determine the location of the latex injectate. Main Outcome MeasureThe location of latex injectate relative to the anatomically identified TMB. ResultsA vertical, linear, hypoechogenic region was sonographically identified arising from the median nerve at the distal carpal tunnel in all 10 specimens and was hypothesized to represent the vertical segment of the TMB. Both transducers allowed identification of the TMB, although localization was subjectively facilitated by the higher frequency transducer. All 10 sonographically guided injections placed latex into and around the TMB of the median nerve, confirming that ultrasound had accurately identified the TMB. ConclusionsSonographic evaluation of the TMB of the median nerve is technically feasible and should be considered when clinically indicated. Further research and clinical experience is necessary to define the role of sonographic TMB imaging in the evaluation and management of patients with carpal tunnel syndrome. Level of EvidenceIV

Microsurgical Anatomy of the Precuneal Artery

The ambiguous term precuneal artery (PA) has several synonyms and anatomic definitions. To examine the arteries of the precuneus and describe the PA and its branching pattern. We defined the PA as the principal arterial supplier of the precuneus. Twenty formalin-fixed, colored latex-injected cadaveric heads were studied with the aid of an operating microscope and microsurgical instrumentation. After removal of the cerebrum from the cranial vault, we examined this vessel's anatomy. Anatomic features of the PA were investigated and assessed in relation to demographic and anthropometric variables. The PA was always a pericallosal artery branch and, more specifically, the superior internal parietal artery (SIPA) in 86.84%, the inferior internal parietal artery in 2.63%, and their common stem in 10.53% of specimens. Anastomosing interhemispheric branches between the PAs were present in 20% of cases. Compared with the right PA, the left anastomosed nearly 3 times more often with the ipsilateral posterior cerebral artery. The average distance of the PA's origin from the posterior limit of the splenium was shown to be 9.4 mm longer in elderly individuals compared with younger ones. The term PA complex (rather than PA) can better describe the principal arterial supplier of the precuneus, and the SIPA, inferior internal parietal artery, and their common stem were shown as the 3 contributing arteries, with the SIPA predominating. The average distance of the PA complex origin from the splenium's posterior limit shows significant variation with respect to age.

Sonographically Guided Anterior Cruciate Ligament Injection: Technique and Validation

ObjectiveTo describe and validate a practical technique for sonographically guided anterior cruciate ligament (ACL) injections. DesignProspective, cadaveric laboratory investigation. SettingProcedural skills laboratory in a tertiary medical center. SubjectsTen unembalmed, cadaveric mid–thigh-knee-ankle foot specimens (5 left knees and 5 right knees; 5 male and 5 female) from 10 donors aged 76 to 93 years (mean 85.6 years) with body mass indices of 17.6 to 42.2 kg/m2 (mean 28.8 kg/m2). MethodsA single, experienced operator used a 22-gauge, 63.5-mm stainless steel needle and a 12-3–MHz linear transducer to inject 1.5 mL of diluted colored latex into the ACLs of 10 unembalmed cadaveric specimens via an in-plane, caudad-to-cephalad approach, long axis to the ACL. At a minimum of 24 hours postinjection, specimens were dissected, and the presence and distribution of latex within the ACL assessed by a study co-investigator. Main OutcomePresence and distribution of latex within the ACL. ResultsAll 10 injections accurately delivered latex into the proximal (femoral), midsubstance, and distal (tibial) portions of the ACL. No specimens exhibited evidence of needle injury or latex infiltration with respect to the menisci, hyaline cartilage, or posterior cruciate ligament. ConclusionsSonographically guided intra-ligamentous ACL injections are technically feasible and can be performed with a high degree of accuracy. Sonographically guided ACL injections could be considered for research and clinical purposes to directly deliver injectable agents into the healing ACL postinjury or postreconstruction.

Anatomical investigation of a new vertical obturator nerve block technique

We evaluated a vertical obturator nerve block (VOB) using a single morphological landmark and no additional distance measurement or obligatory changes of the needle's direction. A total of 88 cadavers (176 lower limbs), prepared using Thiel's embalming method, were examined. The index finger was placed lateral to the palpable pubic tubercle and the needle inserted laterally to the distal part of the fingernail at the tubercle's level and advanced strictly perpendicular to the table's surface. If bone contact was made, the needle was slightly turned to pass the bone distally. Colored latex (5 ml) was then injected. The injection depth was documented, then followed by dissection and nerve exposition. The real skin-nerve distance and the degree of difficulty in orientation and of palpation were measured. Additionally, the dissemination around the nerve or its branches and the intrapelvic spread were documented. The nerve was colored completely in 93.75%, partially in 1.71%, and not colored in 4.54% of cases. The mean injection depth was 3.9 cm (±0.7 SD) and real nerve depth was 3.8 cm (±0.69 SD). Bone contact necessitating the needle's redirection was found in 20 (11.4%) cases. Easy orientation and palpation of the tubercle was always found. In 40 cases, the latex spread via the obturator canal into the lesser pelvis. In this anatomical study, the VOB technique exhibits easy orientation without stimulation or ultrasound guidance. The nerve was located at a constant depth. The injection offered a high percentage of colored nerves.

Sonographic Appearance of the Posterior Interosseous Nerve at the Wrist

The purpose of this study was to determine whether sonography can identify the distal posterior interosseous nerve at the wrist. On the basis of previous anatomic descriptions, high-resolution musculoskeletal sonography was used in an attempt to identify the distal posterior interosseous nerve in the wrists of 20 unembalmed cadaveric specimens (11 male and 9 female; ages 54-98 years). High-frequency scanning (17-5 MHz) of the fourth dorsal extensor compartment revealed a small (1-3 mm) hypoechoic structure located on the compartment floor, presumed to represent the posterior interosseous nerve. Electronic calipers measured the distance between Lister's tubercle and this structure, as well as the structure's radial-ulnar width and volar-dorsal height. The presumed posterior interosseous nerves of 10 specimens were then injected with diluted colored latex using sonographic guidance. Subsequent dissection definitively identified the sonographically visualized and injected structure. Dissection revealed latex within the posterior interosseous nerve in all 10 injected specimens, thus confirming that the sonographically visualized structure represented the distal posterior interosseous nerve. The nerve was identified sonographically in all 20 examined specimens, was located an average of 4.88 mm (range, 2.10-10.0 mm) ulnar to Lister's tubercle, and had an average width and height of 2.35 mm (range, 1.20-3.50 mm) and 1.01 mm (range, 0.80-1.40 mm), respectively. High-resolution sonography can reliably identify the distal posterior interosseous nerve within the fourth dorsal extensor compartment. Clinicians should consider formal evaluation of the posterior interosseous nerve in patients presenting with dorsal wrist pain syndromes. Future investigations should explore the potential role of sonographically guided percutaneous procedures directed at the posterior interosseous nerve.

Accuracy of Ultrasound-Guided Versus Fluoroscopically Guided Contrast-Controlled Piriformis Injections

The purpose of this study was to compare the accuracy of ultrasound-guided piriformis injections with fluoroscopically guided contrast-controlled piriformis injections in a cadaveric model. Twenty piriformis muscles in 10 unembalmed cadavers were injected with liquid latex using both fluoroscopically guided contrast-controlled and US-guided injection techniques. All injections were performed by the same experienced individual. Two different colors of liquid latex were used to differentiate injection placement for each procedure, and the injection order was randomized. The gluteal regions were subsequently dissected by an individual blinded to the injection technique. Colored latex seen within the piriformis muscle, sheath, or both was considered an accurate injection. Nineteen of 20 ultrasound-guided injections (95%) correctly placed the liquid latex within the piriformis muscle, whereas only 6 of the 20 fluoroscopically guided contrast-controlled injections (30%) were accurate (P = .001). The liquid latex in 13 of the 14 missed fluoroscopically guided contrast-controlled piriformis injections and the single missed ultrasound-guided injection was found within the gluteus maximus muscle. In the single remaining missed fluoroscopically guided contrast-controlled piriformis injection, the liquid latex was found within the sciatic nerve. In this cadaveric model, ultrasound-guided piriformis injections were significantly more accurate than fluoroscopically guided contrast-controlled injections. Despite the use of bony landmarks and contrast, most of the fluoroscopically attempted piriformis injections were placed superficially within the gluteus maximus. Clinicians performing piriformis injections should be aware of the potential pitfalls of fluoroscopically guided contrast-controlled piriformis injections and consider using ultrasound guidance to ensure correct needle placement.

Comparison between one midline cutaneous incision and two lateral incisions in the lumbar paraspinal approach by Wiltse: a cadaver study

Wiltse has described in 1968 an intermuscular lumbar approach with two vertical incisions made at 30 mm each on both sides of the midline. Since 1988, Wiltse recommends to practice a single median incision because of aesthetic arguments and because it avoids potential difficulties in case of iterative surgery. In this paper, the goal of authors was to determine the advantages of two lateral incisions, particularly in term of cutaneous vascularization. This cadaveric study concerned ten specimens. Colored latex was injected into the lumbar segmentary arteries before taking a cutaneous flap. We calculated the mean of the number of vessels injected and cut on the midline, then all the 10 mm on both sides. The goal was to establish a cutaneous cartography, and to determine a zone of less vascular sacrifice. The lumbar skin was vascularized by an arteriolar network which spreads out from the midline. At 30 mm from the midline, the number of cut vessels is statistically less than in the others areas (P < 0.05). At this distance, the small arteries are superficial, fine, and the subcutaneous tissue appears poorly vascularized. The two lateral incisions have the advantage compared to a single median incision of being short, and of allowing a direct access to the muscular plan of cleavage without subcutaneous detachment, with a less pressure retraction. We think that an incision at 30 mm from spinous processes is less noxious for the skin because it is located at the border of two vascular territories, which depend of a median network for one, and a lateral network for the other. These incisions generate technical difficulties, however, when the approach is prolonged with the top of L2/L3, when a lateral and/or central canalar decompression is considered, and finally, in the event of iterative surgery.

Preparation of colored latex with polyurea shell by miniemulsion polymerization

Colored latexes with polyurea shell were prepared by applying interfacial polycondensation reaction to the miniemulsion polymerization process. These colored latexes were composed of polystyrene core and polyurea shell, and their particle size was adjusted to <100 nm. Diisocyanate was used as a hydrophobic monomer, and the equivalent mole of diamine was used as a hydrophilic monomer for interfacial polymerization. It was important to control the rate of interfacial polycondensation reaction in order to prepare small particles. Dye preservation property of colored latex loaded with oil-soluble dye was investigated. Polyurea shell formed at the surface of latex particles could restrain the migration of dyes from the latex particles and improve the dye preservation property. The ability to prevent dye migration depended on the composition of the polyurea shell.

Preparation of colored latex containing oil-soluble dyes with high dye content by mini-emulsion polymerization

Polymer particles containing oil-soluble dyes (colored latex particles) were prepared by mini-emulsion polymerization. Copper phthalocyanine dyes and styryl dyes were used as oil-soluble dyes. Highly hydrophobic dyes played the role of hydrophobe by themselves and enabled the full incorporation of dyes in the latex without additional hydrophobes. Two phthalocyanine dyes having similar color were blended in a mini-emulsion polymerization so that the resulting colored latex showed enough strong color depth as a colorant. Colored latexes with high dye content (more than 30 wt% for phthalocyanine dye system and 40 wt% for styryl one) and with particle size less than 100 nm were obtained.