CAD-CAM-assisted esthetic facial surgery.

PURPOSE: This report describes a fully digital workflow for computer-assisted esthetic facial surgery planning and guidance. MATERIAL AND METHODS: Using optical scans, virtual surgery is performed according to the 3-dimensional cephalometric results. Next, surgical templates are generated using rapid prototyping. These templates act as a guide during surgery. RESULTS: The workflow has been tested successfully in 4 esthetic facial surgical procedures (rhinoplasty and genioplasty). In addition to surgical assistance, the advantages of the workflow include the possibility of discussing the treatment plan interactively with the patient and comparing and measuring simulation surgery with the actual outcome. As an additional benefit, the appropriate size of the alloplastic implants can be determined preoperatively. CONCLUSIONS: Templates could improve special procedures in esthetic facial surgery.

Predicting the outcome of renal transplantation.

OBJECTIVE: Renal transplantation has dramatically improved the survival rate of hemodialysis patients. However, with a growing proportion of marginal organs and improved immunosuppression, it is necessary to verify that the established allocation system, mostly based on human leukocyte antigen matching, still meets today's needs. The authors turn to machine-learning techniques to predict, from donor-recipient data, the estimated glomerular filtration rate (eGFR) of the recipient 1 year after transplantation. DESIGN: The patient's eGFR was predicted using donor-recipient characteristics available at the time of transplantation. Donors' data were obtained from Eurotransplant's database, while recipients' details were retrieved from Charité Campus Virchow-Klinikum's database. A total of 707 renal transplantations from cadaveric donors were included. MEASUREMENTS: Two separate datasets were created, taking features with <10% missing values for one and <50% missing values for the other. Four established regressors were run on both datasets, with and without feature selection. RESULTS: The authors obtained a Pearson correlation coefficient between predicted and real eGFR (COR) of 0.48. The best model for the dataset was a Gaussian support vector machine with recursive feature elimination on the more inclusive dataset. All results are available at http://transplant.molgen.mpg.de/. LIMITATIONS: For now, missing values in the data must be predicted and filled in. The performance is not as high as hoped, but the dataset seems to be the main cause. CONCLUSIONS: Predicting the outcome is possible with the dataset at hand (COR=0.48). Valuable features include age and creatinine levels of the donor, as well as sex and weight of the recipient.

Sustained BK viruria as an early marker for the development of BKV-associated nephropathy: analysis of 4128 urine and serum samples.

BACKGROUND: BKV reactivation plays the causative role in the development of BKV-associated nephropathy (BKVAN). Because of the lack of effective therapy, early diagnosis of BKV reactivation is paramount for the prevention of BKVAN. Resting in uroepithelial cells, BKV is excreted first in urine before it can be detected in plasma. The present study analyzed predictive value of BK viruria for the development of BK viremia and its possible advantage for the early BKVAN prediction. METHODS: Total of 4128 urine and serum samples obtained from renal transplant patients were analyzed for BKV positivity by real-time polymerase chain reaction in 433 patients in cross-sectional and in 233 patients in longitudinal manner, respectively. The prospective longitudinal analysis included seven measurements during the first posttransplant year. RESULTS: A total of 7% and 19% patients were positive for BKV in serum and urine, respectively. Sustained BK viruria showed sensitivity of 100% and specificity of 94% for BK viremia and was associated with significantly higher level of BK load than the patients with transient viruria (P<0.01). Interestingly, BK viremia was preceded by BK viruria: the peak of viral load and number of positive patients appeared during the third and fifth posttransplant month for urine and serum, respectively. BKVAN diagnosed in 21.4% of patient with persistent BK viruria appeared 5 and 11 weeks after BKV reactivation in serum and urine, respectively, was detected. CONCLUSION: Sustained BK viruria is a reliable marker allowing an early identification of patients at high risk of BKVAN development and therefore assure precocious therapeutic interventions.

Two-center experience in the treatment of hemorrhoidal disease using Doppler-guided hemorrhoidal artery ligation: functional results after 1-year follow-up.

INTRODUCTION: Doppler-guided hemorrhoidal artery ligation (DGHAL), as a method of treating hemorrhoidal disease, is currently used in many centers across Europe, Asia, and Australia. The aim of our study was to evaluate the clinical effectiveness and functional results of DGHAL as estimated by means of anorectal manometry. MATERIALS AND METHODS: Between 2000 and 2006 the DGHAL procedure was performed on 507 patients with II-IV degree hemorrhoids in two centers (Poland and Austria). Three hundred eight patients were included in the initial phase of the study, designed to estimate the method's effectiveness. During the second phase (199 patients) selected functional results were also assessed. Patients were classified as having grade II (144), III (319), and IV (44) hemorrhoids. RESULTS: There were no intra- and immediate postoperative complications. Good results were reported by 351 patients (69.2%), and were acceptable in a further 75 cases (4.8%). When the patients were grouped according to the stage of hemorrhoidal disease, 133 out of 144 patients (92.4%) with grade II and 272 out of 324 (84%) with grade III had very good or good results. Only 18 out of 44 patients (41%) with grade IV were satisfied with the operation. Fifty-nine patients after anorectal folds, fissure or anal canal polyp excision required analgesics for 1-2 days. Apart from lower contraction amplitude and contraction speed after 1 month there were no differences in anorectal functional tests. CONCLUSION: Based on our results we may conclude that DGHAL is a safe and effective method and may offer an important alternative to operative hemorrhoidectomy with no risk of postoperative stool incontinence, minimal postoperative pain, and early return of patients to their normal activities. Nevertheless, this is a fairly new procedure with a short-term follow-up. Until 5-year observations of large, multicenter, randomized trials are published we cannot recommend this method as a gold-standard procedure, although it still can offer significant benefits to patients.

Doppler-guided hemorrhoidal artery ligation.

BACKGROUND: In 1995, Morinaga reported a new technique for the treatment of hemorrhoids, hemorrhoidal artery ligation (HAL), which uses a specially designed proctoscope coupled with a Doppler transducer for identification and ligation of hemorrhoidal arteries. METHODS: Because the arteries carrying the blood inflow are ligated, internal pressure of the plexus hemorrhoidalis is decreased. RESULTS: We report the results of the first 308 patients (189 male and 119 female; median age 50.1 years) who have been treated at our department since 2002 and followed-up for a median period of 18 months. Eighty-nine patients had grade II, 192 patients had grade III, and 27 patients had grade IV hemorrhoids. The acute symptoms of hemorrhoids were treated immediately by performing HAL. CONCLUSIONS: Our study showed that HAL is painless, effective, and has a low rate of complications. It can be applied in an outpatient setting and is an good alternative to all other hemorrhoid treatment methods.