Despite advancements in medical therapy of Crohn's disease(CD), majority of patients with CD will eventually require surgical intervention, with at least a third of patients requiring multiple surgeries. It is imp...Despite advancements in medical therapy of Crohn's disease(CD), majority of patients with CD will eventually require surgical intervention, with at least a third of patients requiring multiple surgeries. It is important to understand the role and timing of surgery, with the goals of therapy to reduce the need for surgery without increasing the odds of emergency surgery and its associated morbidity, as well as to limit surgical recurrence and avoid intestinal failure. The profile of CD patients requiring surgical intervention has changed over the decades with improvements in medical therapy with immunomodulators and biological agents. The most common indication for surgery is obstruction from stricturing disease, followed by abscesses and fistulae. The risk of gastrointestinal bleeding in CD is high but the likelihood of needing surgery for bleeding is low. Most major gastrointestinal bleeding episodes resolve spontaneously, albeit the risk of re-bleeding is high. The risk of colorectal cancer associated with CD is low. While current surgical guidelines recommend a total proctocolectomy for colorectal cancer associated with CD, subtotal colectomy or segmental colectomy with endoscopic surveillance may be a reasonable option. Approximately 20%-40% of CD patients will need perianal surgery during their lifetime. This review assesses the practice parameters and guidelines in the surgical management of CD, with a focus on the indications for surgery in CD(and when not to operate), and a critical evaluation of the timing and surgical options available to improve outcomes and reduce recurrence rates.展开更多
Purpose:To fine tune the default depth and rate of ablation of the epithelium in cTen^(TM) customized trans-epithelial one-step superficial refractive surgery by the comparison between the attempted post-operative ide...Purpose:To fine tune the default depth and rate of ablation of the epithelium in cTen^(TM) customized trans-epithelial one-step superficial refractive surgery by the comparison between the attempted post-operative ideal corneal shape and the achieved corneal shape.Methods:88 consecutive eyes in 64 patients undergoing trans-epithelial superficial excimer ablation using the iVis laser Suite for either myopic/astigmatic or hyperopic/astigmatic refractive error.Each patient had at least 3 months of post-operative follow-up.Topographic examination of all eyes was carried out pre-operatively and at least 3 months post-operatively using the Precisio^(TM) surgical topographer.The comparison of these two measurements yielded values for depth,volumes and rates of ablated corneal tissue.By determining the different ablation rates of stroma and epithelium,a refinement of the depth of epithelium to be removed and a refinement of the stromal ablation were calculated.The mathematical model was applied on each one of the 88 clinical cases and the parameters for the fine tuning of the default depth and rate of ablation of the epithelium were determined using the least squares method.Results:The calculated pure stromal ablation rate was less than the average epithelium/stroma ablation rate used in planning the treatments by a factor of 0.96.The epithelial thickness predefined ablation assumption used to plan removal of the epithelium was adjusted considering the measured ablation and a radial adjustment function established for the fine tuning of the laser radial efficiency and allowing for the normal thickening of the epithelium in the peripheral cornea.From a clinical point of view,this methodology produces an improvement of the efficacy and a reduction of the variance of the clinical results.Conclusion:Comparison of accurately measured pre and postoperative topographies yields accurately established ablation rates of stroma and epithelium in trans-epithelial one step superficial ablation.展开更多
文摘Despite advancements in medical therapy of Crohn's disease(CD), majority of patients with CD will eventually require surgical intervention, with at least a third of patients requiring multiple surgeries. It is important to understand the role and timing of surgery, with the goals of therapy to reduce the need for surgery without increasing the odds of emergency surgery and its associated morbidity, as well as to limit surgical recurrence and avoid intestinal failure. The profile of CD patients requiring surgical intervention has changed over the decades with improvements in medical therapy with immunomodulators and biological agents. The most common indication for surgery is obstruction from stricturing disease, followed by abscesses and fistulae. The risk of gastrointestinal bleeding in CD is high but the likelihood of needing surgery for bleeding is low. Most major gastrointestinal bleeding episodes resolve spontaneously, albeit the risk of re-bleeding is high. The risk of colorectal cancer associated with CD is low. While current surgical guidelines recommend a total proctocolectomy for colorectal cancer associated with CD, subtotal colectomy or segmental colectomy with endoscopic surveillance may be a reasonable option. Approximately 20%-40% of CD patients will need perianal surgery during their lifetime. This review assesses the practice parameters and guidelines in the surgical management of CD, with a focus on the indications for surgery in CD(and when not to operate), and a critical evaluation of the timing and surgical options available to improve outcomes and reduce recurrence rates.
基金Ethics submission financed by iVis Technologies。
文摘Purpose:To fine tune the default depth and rate of ablation of the epithelium in cTen^(TM) customized trans-epithelial one-step superficial refractive surgery by the comparison between the attempted post-operative ideal corneal shape and the achieved corneal shape.Methods:88 consecutive eyes in 64 patients undergoing trans-epithelial superficial excimer ablation using the iVis laser Suite for either myopic/astigmatic or hyperopic/astigmatic refractive error.Each patient had at least 3 months of post-operative follow-up.Topographic examination of all eyes was carried out pre-operatively and at least 3 months post-operatively using the Precisio^(TM) surgical topographer.The comparison of these two measurements yielded values for depth,volumes and rates of ablated corneal tissue.By determining the different ablation rates of stroma and epithelium,a refinement of the depth of epithelium to be removed and a refinement of the stromal ablation were calculated.The mathematical model was applied on each one of the 88 clinical cases and the parameters for the fine tuning of the default depth and rate of ablation of the epithelium were determined using the least squares method.Results:The calculated pure stromal ablation rate was less than the average epithelium/stroma ablation rate used in planning the treatments by a factor of 0.96.The epithelial thickness predefined ablation assumption used to plan removal of the epithelium was adjusted considering the measured ablation and a radial adjustment function established for the fine tuning of the laser radial efficiency and allowing for the normal thickening of the epithelium in the peripheral cornea.From a clinical point of view,this methodology produces an improvement of the efficacy and a reduction of the variance of the clinical results.Conclusion:Comparison of accurately measured pre and postoperative topographies yields accurately established ablation rates of stroma and epithelium in trans-epithelial one step superficial ablation.
