Placement Of Flaps Research Articles

Single-stage Palatal Lengthening Using Modified Buccinator Myomucosal and Buccal Fat Flaps.

Surgical treatment of velopharyngeal insufficiency (VPI) after primary palatoplasty poses a difficult challenge in cleft care management. Traditional treatment options have shown improved speech outcomes but oftentimes lead to airway obstruction by constriction of the posterior pharynx. The buccinator myomucosal flap is an alternative flap used for VPI correction that re-establishes palatal length and velar sling anatomy by recruiting tissue from the buccal mucosa and buccinator muscle. We present innovative modifications to the original buccinator myomucosal flap by performing the procedure in one stage without a mucosal bridge, incorporating full-thickness buccinator muscle during flap elevation, and placement of bilateral buccal fat flaps. These refinements facilitate wound healing by providing a tension-free closure with both a well-vascularized myomucosal flap and interposed buccal fat flap to prevent scar contracture. Furthermore, no additional surgery is necessary for pedicle division.

TREATMENT OF VERY LARGE TRAUMATIC BONE DEFECTS WITH A BIODEGRADABLE POLYCAPROLACTONE-TRICALCIUM PHOSPHATE 3D-PRINTED SCAFFOLD: A REVIEW OF THREE CLINICAL CASES

The need for an artificial scaffold in very large bone defects is clear, not only to limit the risk of graft harvesting, but also to improve clinical success. The use of custom osteoconductive scaffolds made from biodegradable polyester and ceramics can be a valuable patient friendly option, especially in case of a concomitant infection.Multiple types of scaffolds for the Masquelet procedure (MP) are available, however these frequently demonstrate central graft involution when defects exceed a certain size and the complication rates remains high. This paper describes three infected tibial defect nonunions with a segmental defect over ten centimeters long treated with a customized 3D printed polycaprolactone-tricalcium phosphate (PCL-TCP) cage in combination with biological adjuncts.Three male patients, between the age of 37 and 47, were treated for an infected tibial defect nonunion after sustaining Gustilo grade 3 open fractures. All had a segmental midshaft bone defect of more than ten centimeters (range 11–15cm). First stage MPs consisted of extensive debridement, external fixation and placement of anterior lateral thigh flaps (ALT). Positive cultures were obtained from all patients during this first stage, that were treated with specific systemic antibiotics during 12 weeks. The second stage MP was carried out at least two months after the first stage. CT scans were obtained after the first stage to manufacture defect-specific cages. In the final procedure a custom 3D printed PCL-TCP cage (Osteopore, Singapore) was placed in the defect in combination with biological adjuncts (BMAC, RIA derived autograft, iFactor and BioActive Glass). Bridging of the defect, assessed at six months by CT, was achieved in all cases. SPECT-scans 6 months post-operatively demonstrated active bone regeneration, also involving the central part of the scaffold. All three patients regained function and reported less pain with full weight-bearing.This case report shows that 3D printed PCL-TCP cages in combination with biological adjuncts is a novel addition to the surgical treatment of very large bone defects in (infected) posttraumatic nonunion of the tibia. This combination could overcome some of the current drawbacks in this challenging indication.

Staggered Setting of Latissimus Dorsi and Serratus Anterior Flaps for the Treatment of Scalp Avulsions: A Retrospective Study.

Although the incidence of scalp avulsion has decreased in recent years, it remains a major concern among plastic surgeons. We therefore aimed to introduce an improved free flap technique for repairing scalp avulsion with less tissue from the donor site. This method can achieve maximum primary closure of the donor site and improve its appearance and function as well as reduce the donor-site morbidity by ensuring that a smaller free flap can completely cover the scalp defect. Eight patients with scalp avulsion who had undergone staggered placement of the free flaps were evaluated. Data on the age, cause of scalp avulsion, scalp defect size, degree of avulsion, postoperative complications, and follow-up duration were analyzed. The postoperative evaluation criteria were donor-site sensation, latissimus dorsi muscle strength, upper extremity function, and quality of life. Patients' mean age was 38.7 years. The main cause of scalp avulsion was occupation-related accidents. The mean scalp defect size and postoperative follow-up duration were 26 cm × 20.4 cm and 41.5 months, respectively. One patient developed flap congestion postoperatively. The wounds at the recipient site healed well in all patients. There was no significant difference in the sensation between the surgical and nonsurgical sides. However, the latissimus dorsi muscle strength significantly differed between both sides. The mental component score, which was used to assess quality of life, did not significantly differ between the patients and healthy population, whereas the physical component score significantly differed between the two groups. None of the included patients had severe upper extremity functional limitation. Staggered placement of free flaps achieved maximum primary closure of the donor site and greater scalp avulsion defect coverage with less tissue excised from the donor site. Importantly, donor-site appearance improved and some donor-site functions were preserved postoperatively.

SURGICAL MANIPULATION OF SOFT AND BONE TISSUE IN CONTEMPORARY DENTAL IMPLANTOLOGY

Adequate and correct manipulation of soft and bone tissues during implant therapy is extremelyimportant. Knowledge of the biological, histological and of course the surgical characteristics of the tissues canlargely be a predictor of the correct implant prosthetic rehabilitation. The main aim of this research was to describeall aspects of surgical manipulation of the soft and bone tissues during the dental implantology procedures. We havemade adequate literature research for articles relevant to our topic-surgical manipulation of the soft and hard tissuesduring the dental implantology procedures published in the last two decades (2001-2021). Kew words used for theresearch were: “surgical manipulation”, “dental implantology”, “soft tissues”, “bone tissues” and their combination.Each implantologist should take into account the biological limitations of each patient, as well as the technicallimitations that may occur during the treatment. Oral soft tissues can be affected during the various stages of theimplant treatment. During the planning of a surgical intervention such as the placement of an implant, regardless ofwhether it is an immediate or a delayed loading implant, it is necessary to have an adequate manipulation of thesurrounding soft tissue and bone structures. When designing the flap should be taken into account the degree ofaccessibility required to access the bone, as well as the final position of the flap. It is also of great importance to takeinto account the preservation of good blood supply to the flap. Based on the exposure of bone after elevation, flapscan be classified as either full-thickness or mucoperiosteal flaps and partial-thickness or mucosal flaps. Dependingon how the interdental papilla will be treated, the incisions can either divide the papilla (conventional incision) orpreserve it (papilla-preserving incision). Based on the placement of flaps after surgery, they can be classified as: 1)nondisplaced flaps, where the flap is returned and sutured to its original position, or 2) displaced flaps, which areplaced apically, coronally, or laterally from their original position. The work in bone is quite complex and requiresknowledge of its morphological and histological characteristics. When working on bone, and especially whenplacing dental implants, it is necessary to note that it is necessary to enable constant cooling. The improvement ofold techniques and the development of new technologies have created a revolution in oral implantology, and now atherapist has numerous therapeutic options that can be incorporated into daily practice to facilitate the surgicalapproach itself. Hard-tissue and soft-tissue dental lasers, which are constantly improving and have a wide range ofindications, are becoming a part of everyday dental practice and also show significant advantages compared toconventional instruments and techniques when placing dental implants. Therefore, over time they will become aninvaluable and irreplaceable tool in modern dental implantology. After the performed extensive and deductiveliterature review, it can be concluded that from particular importance is the correct manipulation of soft and bonetissues during dental implantation. After tooth extraction, the placement of dental implants is largely determined bythe integrity of existing hard and soft tissues, such as the aesthetic outcome from the prosthodontic suprastructureover dental implants. Careful assessment of soft and bone tissue loss during implantation is paramount to the successof aesthetic implant procedures

Comparison of Flap and Bank-Angle Steering for Mars Entry

Previous Mars entry, descent, and landing systems have used bank-angle steering during the hypersonic phase of entry to control range. An alternate solution for hypersonic steering is a set of independently articulated aerodynamic flaps. Deflecting these flaps results in trim at nonzero angles of attack and sideslip angles, enabling the vehicle to generate lift in arbitrary directions. This study compares current state-of-the-art bank-angle steering to flap-based steering across several metrics, including aerodynamic control authority, range capability, and response time. The effective bank angle and effective lift-to-drag ratio are developed to compare the control authority between flap and bank-angle steering systems. The shape of the nonaxisymmetric control authority depends on the flap placement, area, and number of flaps; however, flap-based steering systems likely require a mechanism for roll or bank in order to have a uniform control authority. Aerodynamic control authority is then mapped to a range capability. Flap steering vehicles exhibit range capabilities with markedly different shapes than bank-angle steering vehicles with equivalent maximum hypersonic lift-to-drag ratios. Flap steering vehicles are found to be able to rotate directly between angular positions and have both a more uniform and faster response time than bank-angle steering vehicles.

What is the Fate of the Pedicled Buccal Fat Pad Flap When Used During Primary Palatoplasty?

Pedicled buccal fat pad flaps have more recently been applied to primary cleft palate reconstruction, and yet the integrity of the flap and the long-term impact on the palate has not yet been studied. This case study uses magnetic resonance imaging to evaluate the composition of the soft palate 5 years after the interpositional placement of bilateral pedicled buccal fat pad flaps during primary palatoplasty. Anatomical measures are used to quantify the flap and surrounding velopharynx using magnetic resonance imaging and three-dimensional computer technology, indicating that this surgical technique may have a lasting impact for children with cleft palate.

Comparative analysis of treatment of patients with chronic dacryocystitis in early and late postoperative periods

Chronic dacryocystitis (CD) is a common pathology of the lacrimal ducts. The search for the optimal method of endonasal endoscopic dacryocystorhinostomy (EEDCR), which would give a quick, high-quality and lasting effect, as well as a lower percentage of disease relapses, remains relevant. The aim: to analyze the effectiveness of treatment of patients with chronic dacryocystitis in the early and late postoperative periods with the use of various modifications of EEDCR. Materials and methods: The study group (1st group) consisted of 45 patients with CD, who underwent EED-CR according to the developed method, the comparison group (2nd group) included 36 patients who, after performing the developed EEDCRa polyvinyl chloride (PVC) conductor was installed in the area of the dacryorhinostoma. The control group (3rd group) included 28 patients who underwent EEDCR according to the generally accepted method: with preservation and plastic placement of mucous flaps and with the installation of a PVC conductor. Patients of 1stand 2nd groups were divided into 2 subgroups: 1A and 2A included patients who underwent computed tomography of the lacrimal ducts in the preoperative period according to the developed method, and patients of subgroups 1B and 2B – according to the traditional algorithm. In the postoperative period, the severity of lacrimation was assessed according to the Munk scale, the degree of visualization of the dacryorhinostoma was determined, and the lacrimal function was investigated by advanced West nasolacrimal test under endoscopic control. The final treatment efficacy was assessed 1 year after surgery. Results: The best results when tested according to the Munk scale were recorded in subgroups 1A and 1B with a statistically significant difference from subgroups 2A, 2B and 3rd group throughout the early postoperative period and 1 month after surgery (p<0.05).During the observation period of 3, 6 and 12 months, that is, after the removal of the implant from the lacrimal ducts, there was an improvement in the results in patients of subgroups 2A, 2B and 3rd group, and the difference from subgroups 1A and 1B was statistically insignificant (p>0.05).In the early postoperative period, visualization of the dacryorhinostoma was good in all patients. In the late postoperative period, the best results were in subgroup 1A, the worst in 3rd group, but without a statistically significant difference due to a small sample of patients (p>0.05).Reliably better results of the lacrimal function were obtained in subgroups 1A and 1B already from the 3rd day after surgery, as well as in the subsequent periods of the early postoperative period and 1 month after surgery (p<0.05).In subsequent periods of the late postoperative period, this indicator worsened in all clinical groups, the best results were in subgroup 1A, the worst in 3rd group, but due to a small sample of patients, there was no statistically significant difference (p>0.05).The maximum paces of deterioration in visualization of dacryorhinostoma and lacrimal function were observed from the 3rd to 6th months after the operation. The proportion of positive treatment results in 1st group was 97.8%, in 2nd group – 94.4%, and in 3rd group – 85.7%, while the difference between groups 1 and 3 was statistically significant (p<0,05). Conclusions: The developed technique of endonasal endoscopic dacryocystorhinostomy allows achieving stable remission in 97.8% of patients with chronic dacryocystitis, and the use of CT of the lacrimal ducts according to the developed technique allows to improve the results of surgical treatment.

COMPLICATIONS IN SURGICAL TREATMENT OF PATIENTS WITH CHRONIC DACRYOCYSTITIS

Relevance. Effective treatment of chronic dacryocystitis (CD) remains an urgent problem of modern ophthalmology and rhinology. When studying this issue, not enough attention is always paid to complications.
 Objective – to analyze the existing complications in the surgical treatment of patients with СD.
 Material and methods. The study group (1st group) consisted of 45 patients with CD, who underwent endonasal endoscopic dacryocystorhinostomy (EEDCR) according to the developed own method, the comparison group (2nd group) included 36 patients who after performing the developed EEDCR a polyvinyl chloride (PVC) conductor was installed in the area of the dacryorhinostoma. The control group (3rd group) included 28 patients who underwent EEDCR according to the traditional method: with the preservation and plastic placement of mucous flaps and with the installation of PVC-conductor. Patients of the 1st and 2nd groups were divided into 2 subgroups: 1A and 2A included patients who underwent computed tomography (CT) of the lacrimal ducts in the preoperative period according to the developed method and patients of subgroups 1B and 2B – according to the traditional algorithm. Statistical analysis was performed using the licensed program MedCalc (MedCalc Software bvba, Ostend, Belgium; 2017).
 Results. In patients of subgroups 2A, 2B, and group 3 in the period of 1.5 months after surgery, local complications of the eyeball were recorded: epiphora during implant wearing, severe conjunctivitis, prolapse and displacement of the implant, granulation in the lower lacrimal duct, ectopia of the lower lacrimal point. No such complications were observed in patients of subgroups 1A and 1B. In patients of subgroups 1B, 2B, and group 3 in the early postoperative period were recorded varying degrees of swelling of the lower eyelid, as well as nosebleeds after removal of tampons. No such complications were observed in patients of subgroups 1A and 2A, and the difference between the groups was statistically significant (p <0.05).
 Conclusion. CT of the lacrimal ducts and EEDCR according to the developed methods are effective and allow their combined use to avoid local complications from the nasal cavity and eyeball.

Influence of weaning strategy on behavior, humoral indicators of stress, growth, and carcass characteristics.

Weaning is one of the most stressful events a calf experiences in our current beef production system. Its effects may include reduced feed intake, increased activity, slower growth, and increased susceptibility to disease. This study was designed to evaluate weaning after a 7-d placement of nose flaps at 7 mo (N, n = 40) and delaying weaning by 49 d relative to 7-mo weaning (D, n = 39) as alternatives to the industry standard; abrupt weaning at 7 mo of age (A, n = 39). The 4-yr trial utilized Angus and Angus X Senepol steer calves. Calves were randomly assigned to weaning strategy after being stratified by dam parity (heifer/cow), hair coat phenotype (normal/slick), and body weight. Behavioral observations were made on five steers per strategy group per year over the weeks surrounding weaning. Activity levels were determined by accelerometers worn on neck collars. Blood samples were obtained from the observed cattle during the last 2 yr to determine haptoglobin and cortisol concentration. Once weaned, the steers were followed through finishing and carcass characteristics obtained at harvest. Twelve of 38 steers in the N group had sores in their nostrils from the nose flaps when the flaps were removed at weaning of A/N (237 ± 3 d of age). The A and D calves were more active than N calves in the first 2 to 3 d after weaning but settled down to similar activity levels to N by the day 4. The A and D groups were more vocal than N during the same time frame. Cortisol and haptoglobin remained within normal reference ranges. Average daily body weight gain (ADG) was greater for D than A, who in turn had greater ADG than N during the first 42 d after A and N calves were weaned (0.69, 0.54, and 0.37 kg/d for D, A, and N, respectively; P < 0.01). All treatment groups graded Low Choice at harvest and exhibited similar efficiency of gain during growth and finishing (P > 0.2). Based on ADG during the 42 d after weaning, we recommend delaying weaning when available pasture and cow body condition support this strategy. When conditions do not permit delayed weaning, abrupt weaning may be the next viable option based on animal welfare concerns and increased handling to place and remove the flaps. Nose flaps reduced vocalization at weaning but resulted in less postweaning ADG. Based on our data, we suggest that abrupt weaning under the conditions of this study, is less stressful than we perceive it to be, based on calf behavior.

S16-09 SESSION 16: PLANNING/IMAGING – PART II SEPARATING CRANIOPAGUS TWINS: A 4 STAGE APPROACH USING 3D IMAGING TECHNOLOGY

Introduction: Craniopagus twins are the most rare form of conjoined twins, and successful separation poses a significant challenge to both neurosurgical and plastic surgical teams. Total craniopagus twins share a unified calvarium that houses two fused brains with shared venous sinuses. Orientation of total craniopagus twins, as classified by Stone and Goodrich, may be angular or vertical. To overcome the neurosurgical challenge is to separate two fused brains rotated at different orientations and safely separating the share venous system. The plastic surgery team aims to plan the complex cranial vault reconstruction of two fused calvaria. 3D technology was used to assist in these endeavors. One of the senior authors has previously separated 11 cases of craniopagus twins, and the advantages of our most recent approach using 3D technology will be discussed relative to these cases. Methods: Two sets of total craniopagus twins were separated in 4 stages (n=4). 3D technology was used for pre-operative planning, intra-operative execution, and post-operative analysis of reconstructive outcomes. Virtual surgical planning with 3D printed jigs and guides, 3D surface analysis, and 3D printed models were used at each stage. A two-team approach with neurosurgery and plastic surgery was employed at each stage, and 3D-technology was used by each team. Results: Two sets of total craniopagus twins were successfully separated using a 4-stage, two-team approach supplemented by 3D-technology. The neurosurgical team used 3D-printed models of the brains and vasculature to plan and perform dissection. Plastic surgery used VSP to select tissue expanders and design templates for incisions and osteotomies. 3D printed models offered intraoperative reference to safely separate the brain and its vasculature. 3D printed jigs and guides were fit on the calvarium to guide osteotomies for cranial vault reconstruction, and onto the scalp to guide soft tissue reconstruction. Conclusion: Separation the brain and its vasculature was aided by pre-operative 3D printed anatomic models that were then used as freely rotational reference intra-operatively. Calvarial and scalp reconstruction was improved with virtual surgical planning and 3D printed guides at each stage to precisely plan type and placement of tissue expanders, osteotomies and scalp rotation flaps. 3D technology offers anatomic reference and surgical guidance in the multistage separation of total craniopagus twins, and its potential to further assist in such complex surgical endeavors is a topic of continued investigation.

Superficial Keratectomy and Conjunctival Advancement Hood Flap (SKCAHF) for the Management of Bullous Keratopathy: Validation in Dogs With Spontaneous Disease.

To evaluate the efficacy of superficial keratectomy and conjunctival advancement hood flap (SKCAHF) for the treatment of bullous keratopathy in canine patients. Nine dogs (12 eyes) diagnosed with progressive corneal edema underwent superficial keratectomy followed by placement of conjunctival advancement hood flaps. The canine patients were examined pre- and postoperatively using in vivo confocal microscopy, ultrasonic pachymetry (USP), and Fourier-domain optical coherence tomography (FD-OCT). All owners responded to a survey regarding treatment outcomes. Mean central corneal thickness (CCT) as measured by FD-OCT was 1163 ± 290 μm preoperatively and significantly decreased postoperatively to 795 ± 197 μm (P = 0.001), 869 ± 190 μm (P = 0.005), and 969 ± 162 μm (P = 0.033) at median postoperative evaluations occurring at 2.2, 6.8, and 12.3 months, respectively. Owners reported significant improvement (P < 0.05) in vision and corneal cloudiness at 6.8 and 12.3 months postoperatively. The percentage of cornea covered by the conjunctival flap was correlated (P = 0.0159) with a reduction in CCT by USP at 12.3 months postoperatively. All canine patients were comfortable pre- and postoperatively. SKCAHF results in a reduction of corneal thickness in canine patients with bullous keratopathy. The increase in corneal thickness over time, after performing SKCAHF, is likely because of progressive endothelial decompensation. This surgery is a potentially effective intervention for progressive corneal edema in dogs that may have value in treatment of human patients with bullous keratopathy.

From Theory to Evidence

INTRODUCTION: Non-anatomic (distal) placement of vascularized lymph node (VLN) transfers have shown efficacy in the treatment of extremity lymphedema, but the mechanism by which these flaps provide relief of lymphedema remains unclear. Intrinsic lymphovenous connections have been previously shown to exist in the transferred flap. But, the long-term interaction of the VLN flap and surrounding lymphedematous extremity has not been previously investigated. METHODS: A retrospective review of a prospective maintained database of patients who underwent VLN transfer was evaluated. Patients who underwent distal VLN transfer and had greater than one-year follow-up were identified. Lymphodynamic evaluation was performed using indocyanine green (ICG) on identified patients. Migration direction of dye and latency period was evaluated. RESULTS: Twenty patients were identified and met inclusion criteria. Average long-term follow-up was 27.3 months. The average circumference reduction of the affected extremity was 40.5%. Indocyanine green appearance within the VLN flap was found in all patients occurring on average in 178.3 seconds. In all cases, flow occurred in the distal direction (toward the flap) with proximal placement of dye. Latency period was found to inversely correlate with circumference reduction (p<0.01). CONCLUSION: Distal, non-anatomic placement of VLN flaps provide sustained limb circumference reduction in extremity lymphedema patients with at least one year follow-up. Flap integration with the recipient site reliably occurs as witnessed with consistent ICG drainage, and occurs in the gravity-dependent direction. Faster clearance of ICG will result with improved limb circumference reduction.

Experimental model for the study of soft tissue fixation methods on skin-pericranium flaps in rats

To develop an experimental model to study and radiologically monitor displacement of skin flaps in the pericranium of rats subjected to traction and surgical fixation using suture anchored in a skull bone tunnel or with N-butyl-2-cyanoacrylate (Histoacryl™) surgical adhesive. Radiological markers were placed in the subcutis of Wistar rats undergoing subperiosteal detachment of the pericranium with pulling and fixation of the flap. We performed radiography on postoperative days 3, 7, 14, 21, and 45. A p-value of <0.05 was considered significant. Qualitative analysis of the data indicated that the flaps in the surgical adhesive group remained in place with no change from the immediate postoperative position. However, the flaps in the suture anchored in the skull bone tunnel group and in the control group showed similar healing, with a loss of attachment of 9.7% and 22%, respectively, compared with the immediate postoperative position. There was no quantitative difference between the groups. This experimental model created acceptable experimental conditions for testing different soft tissue fixation methods. The use of tissue fixatives contributed to better placement of pericranium-cutaneous flaps, and surgical adhesive was superior to suture anchor in the skull bone tunnel for fixation of pericranium-cutaneous flaps.

Intra-abdominal pedicled rectus abdominis muscle flap for treatment of high-output enterocutaneous fistulae: Case reports and review of literature

Despite advances in nutritional supplementation, sepsis management, percutaneous drainage and surgical technique, enterocutaneous fistulae remain a considerable source of morbidity and mortality. Use of adjunctive modalities including negative pressure wound therapy and fibrin glue have been shown to improve the rapidity of fistula closure; however, the overall rate of closure remains poor. The challenge of managing chronic, high-output proximal enterocutaneous fistulae can be successfully achieved with appropriate medical management and intra-abdominal placement of pedicled rectus abdominis muscle flaps. We report two cases of recalcitrant high output enterocutaneous fistulae that were treated successfully with pedicled intra-abdominal rectus muscle flaps. Indications for pedicled intra-abdominal rectus muscle flaps include persistent patency despite a reasonable trial of non-operative intervention, failure of traditional operative interventions (serosal patch, Graham patch), and persistent electrolyte and nutritional abnormalities in the setting of a high-output fistula.

Flapless conventional thyroidectomy: A prospective, randomized study

Conventional thyroid surgery is one of the most common operations performed worldwide. The conventional technique involves placement of small or large cutaneous flaps. However, the published data regarding flap use for thyroidectomy are contradictory. This study presents the results using a flapless conventional thyroidectomy and the efficacy of this approach in a thyroidectomy. In addition, the study determined whether there are any advantages associated with the use of this approach in comparison to conventional thyroid surgery. One hundred and forty-two patients underwent a thyroidectomy. The patients were randomly assigned to surgical procedures. Patients in Group 1 (n = 70) underwent a conventional thyroidectomy, and patients in Group 2 (n = 70) underwent a conventional thyroidectomy without a cutaneous flap. There was no significant difference between the two groups in terms of age, sex, body mass index, length of incision, gland volume, and length of hospital stay. Postoperative pain was significantly less in Group 2 than in Group 1 (P = 0.006). Patients in Group 2 showed significantly lower requirement for postoperative intravenous analgesic (P = 0.001), and postoperative peroral analgesic (P = 0.023) in comparison to those in Group 1. Incidences of transient vocal cord paralysis and hypocalcemia were 1.4% and 1.4%, respectively. Of 140 patients, 5 (3.6%) developed postoperative wound complications. These results indicate that a flapless thyroidectomy is safe and technically feasible, and therefore could be an alternative to a conventional thyroidectomy.

A Minimally Invasive Technique for Burying Free Flaps and Grafts

The placement of large-volume flaps and grafts into a subcutaneous pocket often requires extensive incisions for accurate placement. We describe a technique that allows for the precise, atraumatic placement of these tissues through minimal incisions. No unusual or expensive surgical instrumentation is required, and the technique is easy to learn. We have found the technique especially useful in the augmentation of severe facial atrophy.

Imagerie post-opératoire de la chirurgie colorectale

Surgery for the treatment of colorectal diseases has been evolving rapidly recently. In addition to classical surgical procedures (colectomy, abdominoperineal resection), new surgical procedures include coloproctectomy with creation of an ileoanal anastomosis and ileal pouch, pelvic reconstructions (omentoplasty, placement of myocutaneous flaps) and creation of different colic anastomoses after anterior rectal resection. Even if computed tomography and fluoroscopic contrast examinations are still commonly used to assess postoperative changes and complications, especially infections, pelvic magnetic resonance imaging is useful to depict postoperative changes, detect complications such as fistulas and tumor recurrence in patients who have undergone surgery for primary or recurrent rectal disease. The main surgical techniques, their respective indications and postsurgical imaging features will be discussed. The main complications and imaging work-up will also be reviewed.

Optimal placement of trailing-edge flaps for helicopter vibration reduction using response surface methods

This study aims to determine optimal locations of dual trailing-edge flaps to achieve minimum hub vibration levels in a helicopter, while incurring low penalty in terms of required trailing-edge flap control power. An aeroelastic analysis based on finite elements in space and time is used in conjunction with an optimal control algorithm to determine the flap time history for vibration minimization. The reduced hub vibration levels and required flap control power (due to flap motion) are the two objectives considered in this study and the flap locations along the blade are the design variables. It is found that second order polynomial response surfaces based on the central composite design of the theory of design of experiments describe both objectives adequately. Numerical studies for a four-bladed hingeless rotor show that both objectives are more sensitive to outboard flap location compared to the inboard flap location by an order of magnitude. Optimization results show a disjoint Pareto surface between the two objectives. Two interesting design points are obtained. The first design gives 77 percent vibration reduction from baseline conditions (no flap motion) with a 7 percent increase in flap power compared to the initial design. The second design yields 70 percent reduction in hub vibration with a 27 percent reduction in flap power from the initial design.

Anatomic and Pathologic Findings at External Phased-Array Pelvic MR Imaging after Surgery for Anorectal Disease

Pelvic magnetic resonance (MR) imaging is useful for identification of postoperative changes, complications, and disease recurrence in patients who have undergone surgery for primary or recurrent anorectal disease. Commonly used interventions include treatment for anorectal carcinoma: anterior rectal resection with or without creation of different colic anastomoses and abdominoperineal excision with or without pelvic reconstruction (omentoplasty, placement of myocutaneous flaps). Other common interventions include treatment for inflammatory bowel disease (coloproctectomy with or without creation of an ileoanal anastomosis and ileal pouch) and treatment for fistulas (placement of flaps or setons). Postoperative anatomic changes and formation of scar tissue can usually be identified with consecutive MR imaging examinations. Pelvic MR imaging is an accurate technique for assessment of complications including anastomotic leakage, septic complications such as fistulas and abscesses, neoplastic recurrence, and other less common complications (perineal hernia, peritoneal pseudocyst). The sophisticated surgical procedures used in rectal surgery can alter normal anatomy and make image interpretation difficult. Thus, familiarity with the appearances of postoperative anatomic changes, complications, and tumor recurrence is essential for accurate MR imaging evaluation after surgery for anorectal disease.

Aeroelastic Modeling of Trailing-Edge-Flap Helicopter Rotors Including Actuator Dynamics

The effect of actuator dynamics on a helicopter rotor with trailing-edge flaps for vibration control is investigated. Trailing-edge flap, actuator, and elastic rotor blade equations of motion are formulated using Hamilton’s variational principle. The coupled nonlinear, periodic equations are solved using finite elements in space and time. The baseline correlation study is based on wind-tunnel test data for a typical five-bladed bearingless rotor system. Good agreement is seen for the blade flap bending, chord bending, and torsion moments. It is shown that actuator dynamics cannot be neglected for a trailing-edge flap system with torsionally soft actuators. The parametric study performed using both coupled flap/actuator model and prescribed flap motion model indicated that the placement of trailing-edge flaps at 78% radius resulted in minimum flap input for this rotor. The vibration reduction level and trend are close between the predictions of both models at different forward speeds. Control inputs predicted by the coupled model show less sensitivity to the forward speed than that of prescribed model.