Experience With Prophylactic Gentamicin During Penile Prosthesis Surgery: A Retrospective Comparison of Two Different Doses

BackgroundGentamicin has been determined to be active against a wide range of bacterial infections and has been commonly used as a preoperative antibiotic for inflatable penile prosthesis (IPP) implantation. However, the best dosing regimen to produce the safest optimal prophylactic effect remains to be determined.AimTo compare low- and high-dose gentamicin as prophylaxis during IPP implantation.MethodsWe retrospectively analyzed two groups of patients who underwent IPP placement from April 14, 2012 through April 13, 2016. Group 1 was composed of 490 patients who underwent IPP placement from April 14, 2012 through April 13, 2014 and received a low dose of preoperative gentamicin at 80 mg every 8 hours for 1 day. Group 2 was composed of 407 patients who underwent IPP placement from April 14, 2014 through April 13, 2016 and received a single high dose of preoperative gentamicin at 5 mg/kg. We compared the infection rates of IPP and any gentamicin-related toxicities. The same surgeon performed all procedures. All patients received additional vancomycin 1 g before incision and at 12 hours postoperatively.OutcomeDemographic data and IPP infection rate were compared and potential toxicities from the higher dose of gentamicin were closely monitored.ResultsThere were no significant differences in mean age, mean body mass index, and mean interval for IPP placement and IPP infection between the two groups. No toxicity was seen with the higher gentamicin dose. Six cases in group 1 (five de novo cases and one redo case, infection rate = 1.22%) and three cases in group 2 (two de novo cases and one redo case, infection rate = 0.74%) were found to have IPP infection. The infection rate in group 2 appeared to be lower than that in group 1, although a significant statistical difference was not achieved (P = .057).Clinical ImplicationsThese findings would help guide urologists in choosing an optimal preoperative gentamicin dose for IPP surgery.Strengths and LimitationsThis is the first study to report on the usage of high-dose preoperative gentamicin for IPP surgery but with limitations as a retrospective study.ConclusionsAlthough not achieving a statistical difference, there was a trend for patients receiving a higher dose of preoperative gentamicin to have a lower IPP infection rate. No toxicity was encountered from the 5-mg/kg gentamicin dose. We recommend following prophylactic high-dose gentamicin guidelines.Xie D, Gheiler V, Lopez I, et al. Experience With Prophylactic Gentamicin During Penile Prosthesis Surgery: A Retrospective Comparison of Two Different Doses. J Sex Med 2017;14:1160–1164.     

Does the preoperative mild renal dysfunction effect mortality and morbidity following valve cardiac surgery?

AimsThe objective of this study was to investigate the effect of preoperative mild renal dysfunction (RD), not requiring dialysis, on mortality and morbidity after valve cardiac surgery (VCS).PopulationWe studied 340 consecutive patients (2008–2012), who underwent VCS with or without coronary artery bypass graft (CABG).MethodsPreoperative RD was calculated with the abbreviated Modification of Diet in Renal Disease formula and was defined as a glomerular filtration rate <60 ml/min/1.73 m². Logistic regression analysis was used to assess the effect of preoperative renal dysfunction (RD) on operative and adverse outcomes.Results80 patients (30%) had preoperative mild RD. Patients with preoperative RD were older, had a higher rate of preoperative anemia (43% vs. 25%, p < 0.001), and more comorbidities. Patients with preoperative RD had worse outcomes with more reoperation (6.8% vs. 2.3%, p < 0.001).ConclusionPreoperative RD was significantly and independently associated with more red blood cell transfusions and longer hospital stay (median 9 vs. 8 days, p < 0.001). Mortality was similar in both groups (3.4% vs. 2.3%, p = 0.43). Preoperative mild RD in patients undergoing cardiac valve surgery is an independent marker of postoperative morbidity.     

Preoperative embolization of primary bone tumors:A case control study

AIM:To study the safety and effectiveness of preoperative embolization of primary bone tumors in relation to intraoperative blood loss,intraoperative blood transfusion volume and surgical time.METHODS:Thirty-three patients underwent preoperative embolization of primary tumors of extremities,hip or vertebrae before resection and stabilization.The primary osseous tumors included giant cell tumors,aneurysmal bone cyst,osteoblastoma,chondroblastoma and chondrosarcoma.Twenty-six patients were included for the statistical analysis(embolization group)as they were operated within 0-48 h within preoperative embolization.A control group(non-embolization group,n = 28)with bone tumor having similar histological diagnosis and operated without embolization was retrieved from hospital record for statistical comparison.RESULTS:The mean intraoperative blood loss was 1300 mL(250-2900 mL),the mean intraoperative blood transfusion was 700 m L(0-1400 m L)and the mean surgical time was 221 ± 76.7 min for embolization group(group Ⅰ,n = 26).Non-embolization group(group Ⅱ,n = 28),the mean intraoperative blood loss was 1800 m L(800-6000 m L),the mean intraoperative blood transfusion was 1400 mL(700-8400 mL)and the meansurgical time was 250 ± 69.7 min.On comparison,statistically significant(P < 0.001)difference was found between embolisation group and non-embolisation group for the amount of blood loss and requirement of blood transfusion.There was no statistical difference between the two groups for the surgical time.No patients developed any angiography or embolization related complications.CONCLUSION:Preoperative embolization of bone tumors is a safe and effective adjunct to the surgical management of primary bone tumors that leads to reduction in intraoperative blood loss and blood transfusion volume.     

Preoperative therapy in locally advanced esophageal cancer

Esophageal cancer is an aggressive malignancy associated with dismal treatment outcomes. Presence of two distinct histopathological types distinguishes it from other gastrointestinal tract malignancies. Surgery is the cornerstone of treatment in locally advanced esophageal cancer(T2 or greater or node positive); however, a high rate of disease recurrence(systemic and loco-regional) and poor survival justifies a continued search for optimal therapy. Various combinations of multimodality treatment(preoperative/perioperative, or postoperative; radiotherapy, chemotherapy, or chemoradiotherapy) are being explored to lower disease recurrence and improve survival. Preoperative therapy followed by surgery is presently considered the standard of care in resectable locally advanced esophageal cancer as postoperative treatment may not be feasible for all the patients due to the morbidity of esophagectomy and prolonged recovery time limiting the tolerance of patient. There are wide variations in the preoperative therapy practiced across the centres depending upon the institutional practices, availability of facilities and personal experiences. There is paucity of literature to standardize the preoperative therapy. Broadly, chemoradiotherapy is the preferred neo-adjuvant modality in western countries whereas chemotherapy alone is considered optimal in the far East. The present review highlights the significant studies to assist in opting for the best evidence based preoperative therapy(radiotherapy, chemotherapy or chemoradiotherapy) for locally advanced esophageal cancer.     

The diagnostic value of multiplanar reconstruction on MDCT colonography for the preoperative staging of colorectal cancer

The purpose of this study was to determine whether multiplanar reconstruction (MPR) images can improve the accuracy of MDCT-based colorectal cancer preoperative staging by receiver-operating characteristic (ROC) analysis. Fifty-five patients with colorectal cancer underwent contrast-enhanced CT colonography using an 8- or 16-row scanner. Two separate interval reviews of the axial MDCT datasets with/without MPR images (coronal and sagittal) were performed independently by two radiologists blinded to both the colonoscopic and histopathologic results. At each review session, the radiologists were asked to determine the colorectal cancer TNM stage within the context of differentiating ≤T3 from T4, N0 from ≥N1 and M0 from M1 using a five-point confidence scale. The radiologists’ performance for staging the colorectal cancer using axial CT datasets with/without MPR images was evaluated using ROC analysis. Sensitivities, specificities and interobserver agreement were assessed. When MPR images were added, significant improvement was achieved by both radiologists for differentiating N0 from ≥N1 in terms of both A_Z (0.651 to 0.769; 0.573 to 0.713) and specificity (26.7 to 69.2%; 23.1 to 76.9%) (P<0.05). For T staging, ROC analysis failed to show a significant improvement in terms of differentiating ≤T3 from T4 for either radiologist (P>0.05), but a significant improvement in the specificity (70 to 90%; 80 to 92%) was achieved by one radiologist (P<0.05). In terms of the M staging, a significant improvement in the Az (0.844 to 0.996) was observed for the combined interpretation of the axial and MPR images by one radiologist (P<0.05). Furthermore, substantial or almost perfect interobserver agreement was achieved for all TNM stagings for the combined interpretations (κ=0.641–0.866), whereas only fair to substantial agreement was achieved for the axial images alone (κ=0.337-0.707). In conclusion, the combined interpretation of the axial and MPR MDCT images significantly improved the local staging of colorectal cancer compared with assessments based on axial images alone.     

Rapid and automatic localization of the anterior and posterior commissure point landmarks in MR volumetric neuroimages

RATIONALE AND OBJECTIVE: Accurate identification of the anterior commissure (AC) and posterior commissure (PC) is critical in neuroradiology, functional neurosurgery, human brain mapping, and neuroscience research. Moreover, major stereotactic brain atlases are based on the AC and PC. Our goal is to provide an algorithm for a rapid, robust, accurate and automatic identification of AC and PC. MATERIALS AND METHOD: The method exploits anatomical and radiological properties of AC, PC and surrounding structures, including morphological variability. The localization is done in two stages: coarse and fine. The coarse stage locates the AC and PC on the midsagittal plane by analyzing their relationships with the corpus callosum, fornix, and brainstem. The fine stage refines the AC and PC in a well-defined volume of interest, analyzing locations of lateral and third ventricles, interhemispheric fissure, and massa intermedia. RESULTS: The algorithm was developed using simple operations, like histogramming, thresholding, region growing, 1D projections. It was tested on 94 diversified T1W and SPGR datasets. After the fine stage, 71 (76%) volumes had an error between 0-1 mm for the AC and 55 (59%) for the PC. The mean errors were 1.0 mm (AC) and 1.0 mm (PC). The accuracy has improved twice due to fine stage processing. The algorithm took about 1 second for coarse and 4 seconds for fine processing on P4, 2.5 GHz. CONCLUSION: The use of anatomical and radiological knowledge including variability in algorithm formulation aids in localization of structures more accurately and robustly. This fully automatic algorithm is potentially useful in clinical setting and for research.     

Spatial location is accurately tracked by human auditory sensory memory: evidence from the mismatch negativity

The nature of spatial representation in human auditory cortex remains elusive. In particular, although humans can discriminate the locations of sounds as close as 1-10 degrees apart, such resolution has not been shown in auditory cortex of humans or animals. We used the mismatch negativity (MMN) event related brain potential to measure the neural response to spatial change in humans in narrow 10 degree spatial steps. Twelve participants were tested using a dense array EEG setup while watching a silent movie and ignoring the sounds. The MMN was reliably elicited by infrequent changes of spatial location of sounds in free field. The MMN amplitude was linearly related to the degree of spatial change with a resolution of at least 10 degrees. These electrophysiological responses occurred within a window of 100-200 milliseconds from stimulus onset, and were localized to the posterior superior temporal gyrus. We conclude that azimuthal spatial displacement is rapidly, accurately and automatically represented in auditory sensory memory in humans, at the level of the auditory cortex.     

The 'Franssen' illusion for short duration tones is preattentive: a study using mismatch negativity

When a tone burst is divided into two parts, an onset transient and a sustained tone smoothly fading on, and these parts are delivered to two stereophonically located loudspeakers in a room, a listener gains the impression that the whole sound is coming from the loudspeaker that actually emits merely the transient. Due to this auditory illusion known as the 'Franssen effect' (FE), the physical and the perceived lateralizations of the sustained sound become different. A two-block mismatch negativity (MMN) paradigm was used to investigate the stage of auditory processing at which this segregation would take place. In one block, standard stimuli were 100 ms, 1 kHz tone bursts emitted by one of the loudspeakers, and deviant stimuli were their split version, with the sustained part switched to the other loudspeaker. In the other block, the roles of the two stimuli were swapped. A room acoustics software was used for generating the signals to a headphone. The responses recorded from 10 subjects displayed no MMN, although the same stimuli but without the transients evoked prominent MMNs. This indicated that the mechanism underlying this illusion modifies the neural representation of the stimulus with FE in such a way that it becomes similar to that of the stimulus without FE before reaching the input of the preattentive mechanism indexed by the MMN. Considering the possible relationship of this illusion to the precedence effect and also the relevant electrophysiological findings in the literature, we conclude that the primary auditory cortex is the most plausible site of the mechanism leading to the FE.     

Generic head models for atlas-based EEG source analysis

We describe a method for using a generic head model, in the form of an anatomical atlas, to produce EEG source localizations. The atlas is fitted to the subject by a nonrigid warp using a set of surface landmarks. The warped atlas is used to compute a finite element model (FEM) of the forward mapping or lead-fields between neural current generators and the EEG electrodes. These lead-fields are used to localize current sources from the subject's EEG data and the sources are then mapped back to the anatomical atlas. This approach provides a mechanism for comparing source localizations across subjects in an atlas-based coordinate system, which can be used in the large fraction of EEG studies in which MR images are not available. The Montreal brain atlas was used as the reference anatomical atlas and 10 individual MR volumes were used to evaluate the method. The atlas was fitted to each subject's head by a thin-plate-spline (TPS) warp. The spatial locations of a generic 155-electrode configuration were used to constrain the warp. For the purposes of evaluation, dipolar sources were placed on the inner cortical surface in the atlas geometry and transferred to each subject's brain space using a polynomial warp. The parameters of the warp were computed using an intensity-based matching of the atlas and subject brains, thus ensuring that the sources were placed at approximately the same anatomical location in each case. Data were simulated in the subject geometry and a dipole fit was performed on these data using an FEM of the TPS warped atlas. The source positions found in the warped atlas were transferred back to the original atlas and compared to the original position. Sources were simulated at 972 locations evenly distributed over the inner cortical surface of the atlas. The mean error over all 10 subjects was 8.1 mm in the subject space and 15.2 mm in the atlas space. In comparison, using an affine transformation of the electrodes into atlas space and an FEM model generated from the atlas produced mean errors of 22.3 mm in subject space and 19.6 mm in atlas space. With a standard three-shell spherical model the errors were 27.2 mm in the subject space and 34.7 mm when mapped to atlas space.     

Neoadjuvant therapy for pancreatic ductal adenocarcinoma: Opportunities for personalized cancer care

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy that is best treated in a multidisciplinary fashion using surgery, chemotherapy, and radiation. Adjuvant chemotherapy has shown to have a significant survival benefit in patients with resected PDAC. However, up to 50% of patients fail to receive adjuvant chemotherapy due to postoperative complications, poor patient performance status or early disease progression. In order to ensure the delivery of chemotherapy, an alternative strategy is to administer systemic treatment prior to surgery. Precision oncology refers to the application of diverse strategies to target therapies specific to characteristics of a patient’s cancer. While traditionally emphasized in selecting targeted therapies based on molecular, genetic, and radiographic biomarkers for patients with metastatic disease, the neoadjuvant setting is a prime opportunity to utilize personalized approaches. In this article, we describe the current evidence for the use of neoadjuvant therapy (NT) and highlight unique opportunities for personalized care in patients with PDAC undergoing NT.