Multiple-stage Procedure Research Articles

A one-covariate-at-a-time multiple testing approach to variable selection in additive models

. This article proposes a One-Covariate-at-a-time Multiple Testing (OCMT) approach to choose significant variables in high-dimensional nonparametric additive regression models. Similarly to Chudik, Kapetanios, and Pesaran, we consider the statistical significance of individual nonparametric additive components one at a time and take into account the multiple testing nature of the problem. Both one-stage and multiple-stage procedures are considered. The former works well in terms of the true positive rate only if the net effects of all signals are strong enough; the latter helps to pick up hidden signals that have weak net effects. Simulations demonstrate the good finite-sample performance of the proposed procedures. As an empirical illustration, we apply the OCMT procedure to a dataset extracted from the Longitudinal Survey on Rural Urban Migration in China. We find that our procedure works well in terms of out-of-sample root mean square forecast errors, compared with competing methods such as adaptive group Lasso (AGLASSO).

Multiple-site neural tube defects complicated by multiple-site split cord malformations and thickened filum terminale: experience at a pediatric neurosurgical teaching hospital in Ethiopia. Illustrative case.

BACKGROUNDMultiple-site open neural tube defects (MNTDs) and multiple-site split cord malformations (MSCMs) are extremely rare congenital anomalies that are defined by the simultaneous noncontiguous occurrence of more than one neural tube defect (NTD) and split cord malformation (SCM), respectively, in a single case with normal neural tissue in between. This work shows the cooccurrence of MNTDs and MSCMs, which has never been reported in the literature.OBSERVATIONSA single-stage repair for a 13-day-old female neonate with a preoperative diagnosis of MNTDs (thoracic meningocele and thoracolumbar myelomeningocele) plus an additional intraoperative diagnosis of MSCMs (type 3c) of thoracic and thoracolumbar spine, and thickened filum terminale was done with a favorable smooth postoperative course.LESSONSThe use of intraoperative meticulous surgical technique along with preoperative skin stigmata helped for anticipation, detection, and treatment of associated complex spinal MNTDs, especially in resource-limited settings, where preoperative magnetic resonance imaging is not routinely used. Whether to repair the MNTDs as a single- versus multiple-stage procedure is mainly a function of the patient’s tolerance to the duration of anesthesia and the anticipated blood loss for the patient’s age. The overall developmental biology and long-term clinical outcome of MNTDs compared to single NTD/SCM is poorly understood and needs further study.

Surgical Management of Bronchial Stump Complication in Cadaveric Lobar Lung Transplantation

Introduction Lobar lung transplantation (LLTx) allows the use of oversized grafts for small recipients. In this technically demanding and not widely adopted procedure, prolonged air leak, kinking of vascular anastomoses and remaining dead space are frequent complications. We describe our experience in treatening the rarely reported bronchial stump insu!cency (BSI) after LLTx. Case Report Between 1993-2016 we performed 120 cases of LLTx in our center. Among these, 3 developed BSI with empyema. A) 48 year old female with Langerhanscell histiocytosis and BSI of the resected left lower lobe; B) 44 year old male with cystic fibrosis and BSI of the resected right lower lobe; C) 62 year old male with idiopathic pulmonary fibrosis and BSI of the resected right lower lobe. Occurrence of fistula was observed 78 days, 29 days and 39 days after LLTx in A, B and C, respectively. The 3 cases underwent accelerated treatment, consisting of radical debridement of the pleural cavity, packing with wet dressings of diluted 10% povidoneiodine, closure of the bronchial fistula, repeated change of dressings every 2 to 3 days until the chest is macroscopically clean and finally reinforcement of the stump with omentoplasty. Four surgical steps were necessary in case A and C, two in case B. Case A and B recovered well within 6 and 3 days of ICU and had 22 and 39 days overall re-hospitalization, respectively. Case C died 10 days after successful fistula revision due colitis with sepsis in aplasia. Summary A prominent bronchus stump after lower lobectomy in LLTx may cause secretion congestion and focal inflammation that results in BSI. Due to anatomical reasons, a bronchus stump may not be avoided in case of LLTx with right lower lobe resection. Insufficiency can be treated successfully utilizing a multiple stage procedure with suture of the bronchus and covering with omentum flap.

Management of late onset septic complications after IPOM implantation: case series from ahernia center

The intraperitoneal onlay mesh (IPOM) is for many surgeons apragmatic solution for the operative treatment of extensive and complex abdominal wall hernias. Afew years after mesh implantation we are now faced with anumber of late complications of the IPOM procedure. Chronic septic complications, such as mesh infections and fistula formation have an outstanding position. With this case series we would like to share our experiences with the operative treatment of severe late onset septic complications after abdominal wall augmentation with IPOM. Furthermore, the current indications for the IPOM procedure are discussed. For the period February 2016-July 2019 a total of 10patients with late septic complications after IPOM implantation were treated in our clinic. The index interventions took place between 2010 and 2017. The clinical picture varied from mesh infections with only minor symptoms to formation of multiple intestinal fistulas. Multiple stage procedures were required in 9out of the 10patients in order to achieve sufficient decontamination of the surgical field. Due to enterocutaneous fistulas, bowel resection was performed in 5patients. The mesh could be preserved in situ in only one patient. For the reconstruction of the abdominal wall, both plastic surgical methods and implantation of absorbable and non-absorbable meshes were used. Aconsistent treatment with great effort is required for septic complications of the IPOM procedure. The interventions are often associated with extensive adhesiolysis and intestinal resection. Therefore, the indications for intraperitoneal mesh implantation should be handled with caution and an alternative surgical procedure should be considered. There are still special cases, such as hernias with very large abdominal wall defects in which the IPOM method is asuitable treatment option for tension-free reconstruction.

Ultra-simplified Single-Step Fabrication of Microstructured Optical Fiber

Manufacturing optical fibers with a microstructured cross-section relies on the production of a fiber preform in a multiple-stage procedure, and drawing of the preform to fiber. These processes encompass the use of several dedicated and sophisticated equipment, including a fiber drawing tower. Here we demonstrate the use of a commercial table-top low-cost filament extruder to produce optical fibers with complex microstructure in a single step - from the pellets of the optical material directly to the final fiber. The process does not include the use of an optical fiber drawing tower and is time, electrical power, and floor space efficient. Different fiber geometries (hexagonal-lattice solid core, suspended core and hollow core) were successfully fabricated and their geometries evaluated. Air guidance in a wavelength range where the fiber material is opaque was shown in the hollow core fiber.

Outcomes of preoperative anal dilatation for Hirschsprung disease

Background/PurposeThere are some studies about the effect of postoperative anal dilatation on anastomotic stenosis and Hirschsprung-associated enterocolitis (HAEC), but we have not seen any report about preoperative anal dilatation. We hypothesized that preoperative anal dilatation could reduce the incidence of HAEC and facilitate the operation. We aim to compare the HAEC rates and postoperative complications between groups who either had or did not have anal dilatations (AD or NAD) prescribed before laparoscopic-assisted Soave pull-through procedures for Hirschsprung disease (HD); by this means, we will evaluate the benefit of dilatations before the surgery for HD. MethodsA retrospective review of children with HD operated in our hospital between 2014 and 2018 was performed. Those with 21 trisomy, total colonic aganglionosis, multiple stage procedures, serious congenital malformations, and lost to follow-up were excluded. Patients were divided into preoperative anal dilatation group (AD group) and no preoperative anal dilatation group (NAD group). Routine anal dilatation was performed in both groups from 2 weeks after laparoscopic-assisted Soave pull-through. The anal dilatation was carried out daily with metal anal dilators with size appropriate to the age of the child. The size of the anal dilators was increased by 1 mm every 2 weeks for at least 3 months. Demographic data, operation time, pre- and postoperative HAEC rates and postoperative obstructive symptoms between groups were compared. Significance was considered at P < 0.05. ResultsThere were 95 children (17 female and 78 male) included, 36 AD and 59 NAD. There was no significant difference in demographic data between the two groups. The incidence of HAEC between the groups was not different both preoperatively (14% vs. 24%, P = 0.298) and postoperatively (11% vs. 19%, P = 0.171). The postoperative obstructive symptoms rates were 19% versus 22% for the AD and NAD groups, respectively (P = 0.802). The operation time of group AD was significantly shorter than that of group NAD (P = 0.008). Preoperative anal dilatation could shorten the operation time in short and typical-segment (2.08 ± 0.39 vs. 2.67 ± 0.37, P = 0.009 and 3.05 ± 0.38 vs. 3.29 ± 0.46, P = 0.042), but has no significant effect on long-segment disease (3.85 ± 0.41 vs. 3.89 ± 0.30, P = 0.839). ConclusionWe have not shown a reduced risk of developing HAEC or postoperative obstructive symptoms if anal dilatations are prescribed before surgery. However, it may decrease the difficulties of surgeries, so the operative time is shortened. Level of evidencePrognosis study. LevelII.

Infrarenal aortic repair with or without false lumen intentional placement of endografts for hybrid management of complex aortic dissection

ObjectiveAortic dissection (AD) often involves the infrarenal aorta. We review our experience with open infrarenal aortic repair with or without false lumen intentional placement (FLIP) of endografts in the proximal dissected aorta as part of a hybrid strategy to treat complex AD. MethodsA prospectively maintained database of patients undergoing intervention for AD was reviewed. Data regarding diagnosis, imaging features, nature of the infrarenal repair (one- vs two-stage procedure), endoleaks, need for additional interventions, morbidity, and mortality were collected. ResultsBetween 2006 and 2017, there were 16 patients with AD with thoracoabdominal aortic aneurysm (TAAA), malperfusion, or both who underwent open infrarenal aortic repair or replacement combined with endovascular repair in a single- or multiple-stage procedure. Fifteen patients had a chronic AD and one patient had an acute AD. The most common indication for intervention was absolute size or rapid growth of the abdominal, thoracic, or thoracoabdominal aortic aneurysm (65%). In four patients with AD, the infrarenal replacement surgical graft was used as a common distal seal zone, allowing FLIP of an endograft to treat the proximal AD. Ten (62%) cases were done in two or more stages. Three patients had infrarenal aortic replacement with debranching only. In two of these patients, the proximal dissected aorta has remained stable without aneurysmal degeneration. One patient died as a result of rupture of his aneurysm while awaiting the second stage (perioperative mortality, 6%). Patients were observed from 1 month to 7 years. One patient had a stable type II endoleak, and one patient required subsequent replacement of ascending aortic arch for aneurysmal disease. One patient died of unrelated causes on follow-up. ConclusionsHybrid infrarenal aortic repair for treatment of complex AD can be performed with low morbidity and mortality and excellent medium-term results. This strategy can resolve malperfusion while simultaneously creating a landing zone using the false lumen as the conduit for the stent graft (FLIP) in selected patients. The FLIP technique allows full expansion of the endograft, potential preservation of lumbar and intercostal artery flow, and exclusion of the weaker false lumen while, in some cases, decompressing and thus stabilizing the proximal dissected aorta.

Multiple-stage sampling procedure for covariate-adjusted response-adaptive designs

Covariate-adjusted response-adaptive (CARA) design becomes an important statistical tool for evaluating and comparing the performance of treatments when targeted medicine and adaptive therapy become important medical innovations. Due to the nature of the adaptive therapies of interest and how subjects accrue to a sampling procedure, it is of interest how to control the sample size sequentially such that the estimates of treatment effects have satisfactory precision in addition to its asymptotic properties. In this paper, we apply a multiple-stage sequential sampling method to CARA design in such a way that the control of the sample size is more feasible. The theoretical properties of the proposed method, including the estimates of regression parameters and the allocation probabilities under this randomly stopped sampling procedure, are discussed. The numerical results based on synthesized data and a real example are presented.

Intersphincteric completion proctectomy with omentoplasty for chronic presacral sinus after low anterior resection for rectal cancer.

This study aimed to determine the clinical outcome of salvage surgery without restoring continuity for symptomatic chronic presacral sinus after low anterior resection (LAR) for rectal cancer. Out of a prospective cohort of 46 patients with chronic presacral sinus (> 1 year after LAR), 27 underwent completion proctectomy with omentoplasty between January 2005 and July 2014. The initial treatment for rectal cancer included neoadjuvant radiotherapy in 26 (96%) patients. Besides a chronic presacral sinus, a secondary fistula was present in 15 (56%) patients. Definitive salvage surgery was performed after a median of 40 (12-350) months from the primary resection. The median hospital stay after single- and multiple-stage salvage surgery was 11 and 17 days. Postoperative complications occurred in 44% of patients. The re-intervention rate was 33% with a range of 1-10 interventions per patient. During a median follow-up of 20 (4-45) months from salvage surgery, healing of the chronic presacral sinus occurred in 78% of patients, with a healing rate after single- and multiple-stage procedures of 88% and 64% respectively (P = 0.19). Patients with a symptomatic chronic presacral sinus after LAR for rectal cancer, in whom restoration of continuity is not intended, can be effectively managed by completion proctectomy with complete debridement of the sinus and fistula tracts followed by an omentoplasty to fill the presacral cavity, preferably as a single-stage procedure.

Spectrally Efficient OFDM Pilot Waveform for Channel Estimation

Pilot-aided channel estimation is essential to orthogonal frequency division multiplexing systems and standards. Under the system setup that data and pilot waveforms are processed individually for enhancing the spectral efficiency of the composite waveform, pilot patterns are designed here to jointly optimize channel estimation on quasistatic multipath channels and provide extremely high spectral compactness by suppressing spectral sidelobes. Specifically, a general constraint on pilot pattern is developed to endow the pilot waveform with very small spectral sidelobes and thus compact spectrum. Using the constraint, systematic multiple-stage design procedures are proposed to develop the desired pilot patterns achieving Cramer Rao bound for channel estimation on quasistatic multipath channels while providing fast decaying spectral sidelobes. Among the demonstrated pilot patterns achieving optimum channel estimation, the pilot waveforms using $\mathcal {A}_{I}$ - and $\mathcal {B}_{I}$ -typed pilot patterns developed from the procedures are shown to exhibit higher spectral compactness than conventional pilot waveforms. Besides, $\mathcal {C}_{I}$ -typed pilot pattern that exploits extremely high spectral compactness without resort to channel estimation optimization is also developed. By sacrificing a slight loss in channel estimation, the pilot waveforms using $ \mathcal {C}_{I}$ -typed pilot pattern are shown to exhibit spectrums approaching the Nyquist spectrum.

Surgical aspects of ambiguous genitalia associated with congenital adrenal hyperplasia

Aim The aim of the study was to review the current approach to manage ambiguous genitalia caused by CAH. Methods This was a retrospective study of 30 patientswith CAH and ambiguous genitalia treated over 10 years. Age at presentation, degree of verilization, preoperative diagnostic studies, operative technique, blood loss, outcome, and follow-up period were the studied variables. Results The older 19 patients underwent single-stage feminizing genitoplasty and the younger 11 patients underwent a multiple-stage procedure. All patients had undergone clitoroplasty, clitoral recession, or resection. Postoperative complications documented in 23% of the patients included atrophy of the clitoris, flaps complication, and vaginal stenosis. The anatomic and cosmetic outcomes were considered good or satisfactory in 70% and 20% of cases, respectively, and poor in 10% of cases. Conclusion One-stage or multiple-stage feminizing genitoplasty gives a high percentage of satisfactory cosmetic outcomes. TUM can be implemented to achieve excellent results for complex genitourinary anomalies. Keywords : adrenal hyperplasia, congenital, genitoplasty, intersex

MP30-17 NATURAL HISTORY OF RESIDUAL FRAGMENTS FOLLOWING PERCUTANEOUS NEPHROSTOLITHOTOMY

You have accessJournal of UrologyStone Disease: Surgical Therapy III1 Apr 2015MP30-17 NATURAL HISTORY OF RESIDUAL FRAGMENTS FOLLOWING PERCUTANEOUS NEPHROSTOLITHOTOMY Kyle Wood, Marc Colaco, Juan Mainez, Ilya Gorbachinsky, Miguel Osorio, Eliud Sanchez, Majid Mirzazadeh, Dean Assimos, and Jorge Gutierrez-Aceves Kyle WoodKyle Wood More articles by this author , Marc ColacoMarc Colaco More articles by this author , Juan MainezJuan Mainez More articles by this author , Ilya GorbachinskyIlya Gorbachinsky More articles by this author , Miguel OsorioMiguel Osorio More articles by this author , Eliud SanchezEliud Sanchez More articles by this author , Majid MirzazadehMajid Mirzazadeh More articles by this author , Dean AssimosDean Assimos More articles by this author , and Jorge Gutierrez-AcevesJorge Gutierrez-Aceves More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.599AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Percutaneous Nephrostolithotomy (PCNL) is the method of choice to treat large kidney stones. Large stone burdens require staged PCNL procedures to remove residual fragments. This study evaluates the natural history of residual fragments after PCNL. METHODS Data was retrospectively collected from all patients whom underwent PCNL between January 2009 and January 2014. For patients that underwent a multiple stage procedures, data was collected from the final stage of their treatment. Demographic information regarding age, gender, BMI, medical comorbidity, and stone composition were collected. Computerized tomography (CT) scans were taken after the final stage. Each CT was analyzed as to remnant number, size, and location. All cases were then cross-referenced for other stone-related events (defined as symptomatic presentation resulting in the need for an additional stone treatment) occurring within 1 year of initial treatment. RESULTS A total of 515 patients were included of which 420 patients had complete data. There was no significant difference in gender or rates of co-morbidities between groups. Patients with no remnant stone demonstrated a significantly lower reintervention rate than those in whom remnants were found (7.7% reintervention rate versus 28.9%, p<0.0001). These differences remained true when controlled for age, gender, and comorbidity status. For patients that did demonstrate remnants, substratification by number of stone remnants showed that patients with multiple stone remnants had significantly more reintervention than patients with a single stone remnant regardless of total stone burden (36.8% reintervention versus 21.0%, p=0.05). Single stone remnants found in the lower calyces demonstrated significantly lower reintervention rates than those left in the middle or upper calyces (p<0.01). Reintervention rates were 16.75, 28.6%, 36.8%, 45.8% for lower, upper, pelvic/multiple, middle calyx respectively. A total of 300 patients had BMI data. Average BMI of all patients was 30.3. Patients with a higher BMI (>25) had more need for second procedures (22.8% versus 11.2%, p=0.02). CaOx stones are less likely to require a second treatment than CaP (9.4% versus 22.2%, p<0.01). CaOx stones had significantly less residuals than CaP stones (42.5% versus 52.7%, p < 0.05). CONCLUSIONS This study defined parameters seen on postsurgical CT scans as well as patient characteristics and stone type that can help in defining risk of future stone events and determine need for staged PCNL. Using these variables, the odds ratio of a future stone event can be calculated. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e353 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kyle Wood More articles by this author Marc Colaco More articles by this author Juan Mainez More articles by this author Ilya Gorbachinsky More articles by this author Miguel Osorio More articles by this author Eliud Sanchez More articles by this author Majid Mirzazadeh More articles by this author Dean Assimos More articles by this author Jorge Gutierrez-Aceves More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Nonunions and malunions of the pelvis.

Neglected pelvic fractures manifesting as pelvic nonunion or malunion are usually due to inadequate initial fixation or negligence of the injury because of increased attention towards other associated life-threatening conditions. The management of such injuries is complex. A systematic review was conducted to spot the clinical manifestations, evaluation, management and outcome of pelvic nonunion and malunion. Two databases ("Pubmed" and "Google scholar") were searched to look for relevant literature on pelvic non-union and malunion. The search was limited to 'English language' and 'Human being'. A total of 500 articles found, of which 10 articles were only reviewed which met the inclusion criteria. These articles discussed the clinical management and treatment of pelvic malunion and non-union following trauma without associated acetabular injury. The usual presentations of pelvic non-union and malunion are pain, deformity, gait abnormality or instability. A detailed preoperative evaluation is essential as a majority of them have associated hip and spine injury which may be the cause of symptoms. Radiographs and 3D CT scans have helped surgeons in deciding the best way of management. The surgeries are usually complexand may need multiple-staged procedures. Soft tissue release, multiple osteotomies to achieve anatomical or near-anatomical reduction, augmentation of healing process using bone graft and stabilizing the nonunion/ osteotomy site using plates/screws/rods is the basic principle of surgery. Per-operative use of somato-sensory evoked potential evaluation helps the surgeon in preventing iatrogenic nerve injury. Despite these precautions and surgeries, most of the patients do not regain their preinjury functional activity.

Single Stage Correction of Rectovestibular Fistula

Introduction: The aim of this study was to determine the feasibility, safety, cost effectiveness and functional outcome between single stage and multiple stage operation of anorectal malformation (ARM) with rectovestibular fistula (RVF).Materials &amp; Methods: This interventional study was conducted on 40 female children born with ARM with RVF from July 2007 to June 2009 in the Department of Pediatric Surgery, Dhaka Medical College Hospital. Their age range was from 3 months to 7 years. Anterior sagittal anorectoplasty (ASARP) was done as definitive treatment of RVF. 20 out of 40 patients underwent single stage procedure and the rest underwent multiple stage procedure. Good preoperative bowel preparation and postoperative wound care were ensured for optimum outcome.Results: Mean operating time was 70 minutes in single stage and 80 minutes in multi stage definitive procedure. Average hospital stay was 10 days in single stage procedure where as 22-24 days in multi stage procedure. Partial perineal wound dehiscence occurred in two patients with single stage procedure and one patient with multi stage procedure. Wound infection was seen in two patients of single stage and also two patients of multi stage procedures. Fecal continence was good in all patients older than 3 years. Average number of bowel movement was 2-3 times daily in older patients and 2-4 in younger patients. Constipation developed in three patients with multiple stage procedure and in two patients with single stage procedure. Both groups were managed conservatively for all complications. In Dhaka Medical College Hospital, treatment cost is mostly free, so we could not compare this cost but the incidental expenses in single stage treatment was Tk. 10,000.00 and Tk. 30,000.00 in multistage treatment in three settings.Conclusion: Adequate preoperative bowel preparation, good surgical skill, proper analgesia and postoperative wound care remain the key factors to produce a cost effective excellent outcome of single stage correction of RVF.DOI: http://dx.doi.org/10.3329/jpsb.v1i2.19523

Nonsyndromic Mandibular Symphysis Cleft

Median cleft of lower lip and mandible is a rare congenital anomaly described as cleft number 30 of Tessier's classification. In minor forms only lower lip cleft is seen. We report the case of a patient with median cleft of lower lip, severe ankyloglossia, cleft of mandibular symphysis, and residual cleft involving on right soft palate and associated with other facial clefts. These deformities were corrected in multiple stage procedure, consisting of release of the tongue from floor of the mouth and lower alveolus and fixation of the mandibular cleft done with right iliac bone graft using stainless steel miniplate.

SIU/ICUD Consultation on Urethral Strictures: Anterior Urethra—Lichen Sclerosus

We reviewed the current literature on lichen sclerosus as it related to urethral stricture disease using MEDLINE and PubMed (U.S. National Library of Medicine, National Institutes of Health) up to the current time. We identified 65 reports, 40 of which were considered relevant and form the basis of this review. Lichen sclerosus is now the accepted term, and balanitis xerotica obliterans is no longer acceptable. This common chronic inflammatory skin condition, mainly affecting the genitalia, remains an enigma, with uncertain etiology, varied presentation, and multiple treatments. In the early stages of the condition, a short course of steroids may be beneficial for some patients. If persistent, patients need long-term surveillance because of the potential development of squamous cell carcinoma. If diagnosed early, lichen sclerosus can be controlled, preventing progression. But once the disease has progressed, it is very difficult to treat. Surgical treatment by circumcision can be curative if the disease is treated early when still localized. Once progression to urethral involvement has occurred, treatment is much more difficult. Meatal stenosis alone is likely to require meatotomy or meatoplasty. Treatment of the involved urethra requires urethroplasty. Single-stage and multiple-stage procedures using oral mucosa have both been reported to give acceptable results, but the use of skin, genital or nongenital, is not recommended, because being skin, it remains prone to lichen sclerosus. With extensive disease, affecting the full length of the urethra, consideration should be given to perineal urethrostomy. A significant number of patients may prefer this simpler option.

Bronchial fistula after lobar size reduction for bilateral lung transplantation in Kartagener's syndrome: a surgical challenge

Bilateral lung transplantation was performed in a 52-year old man with end-stage Kartagener's syndrome. A postimplantation right lower lobectomy was required for volume reduction and dextrocardia. A bronchial fistula developed with an intractable colonized residual pleural cavity. Closure was obtained successfully with multiple-stage procedures including decortication, muscle flap and an open-window thoracostomy without modification of the immunosuppressive protocol.

Simultane antegrad-retrograde Steintherapie

The current guidelines recommend percutaneous nephrolithotomy (PCNL) as the first choice procedure for large stone masses. Complex stone situations, such as formed stones or large peripheral stone masses, however, often necessitate several access points and multiple stage procedures. In such cases open surgical stone removal is often used. An alternative is simultaneous antegrade-retrograde stone therapy in which PCNL is combined with flexible ureterorenoscopy (fURS). Both procedures complement each other in that fURS allows access to narrow calyces and PCNL the simple removal of buried concretions via the percutaneous shaft without excessive disintegration. Even difficult stone situations can be resolved simultaneously. Disadvantages are the high personnel and instrumental involvement (two endoscopic procedures with two endoscope towers and two operators) which is not adequately reflected in the diagnosis-related groups (DRG) remuneration system. Additionally simultaneous stone treatment is normally carried out in the supine lithotomy position so that even an experienced percutaneous surgeon is confronted with a new situation and a certain learning curve. Our own experiences and that of other working groups show, however, that the simultaneous approach represents an attractive and effective addition to minimally invasive stone therapy if the appropriate equipment and corresponding expertise are available.

A penalized likelihood estimation approach to semiparametric sample selection binary response modeling

Sample selection models are employed when an outcome of interest is observed for a restricted non-randomly selected sample of the population. We consider the case in which the response is binary and continuous covariates have a nonlinear relationship to the outcome. We introduce two statistical methods for the estimation of two binary regression models involving semiparametric predictors in the presence of non-random sample selection. This is achieved using a multiple-stage procedure, and a newly developed simultaneous equation estimation scheme. Both approaches are based on the penalized likelihood estimation framework. The problems of identification and inference are also discussed. The empirical properties of the proposed approaches are studied through a simulation study. The methods are then illustrated using data from the American National Election Study where the aim is to quantify public support for school integration. If non-random sample selection is neglected then the predicted probability of giving, for instance, a supportive response may be biased, an issue that can be tackled using the proposed tools.

An alternative management option for infected non-union of long bone fractures.

Management of infected non-union following fracture of a long bone is a challenge to the orthopaedic surgeon. Several methods of treating these cases have been described.(1-7) Although reports of single stage or multiple stage procedures exist in the literature, general consensus appears to favour a two-stage approach with initial debridement followed by the use of local antibiotic cement in the first stage.(2,5,8) This antibiotic-impregnated cement has been reported in previous papers as placed around an intramedullary nail or via antibiotic cement beads,(4-6,9) Cement beads offer no mechanical stability to the fracture site. Placing cement around an intramedullary device provides added concerns, such as cement nail debonding and the continued presence of metal, which could cause persistence of infection when in contact with endosteal sequestrate. We describe the use of an antibiotic cement nail fashioned by hand intra-operatively around a length of nylon tape. This eliminates the need for further metalwork during the infected stage, thereby reducing the chance of persistent non-union as well as providing some stability across the fracture site.