Impact of Margin Assessment Method on Positive Margin Rate and Total Volume Excised

Background

For breast-conserving surgery, the method of margin assessment that most frequently achieves negative margins without increasing the volume of tissue excised is uncertain. We examined our institutional experience with three different margin assessment methods used by six experienced breast surgeons.

Methods

Patients undergoing breast-conserving surgery for invasive carcinoma during July to December of a representative year during which each method was performed (perpendicular, 2003; tangential, 2004; cavity shave, 2011) were included. The effect of margin method on the positive margin rate at first excision and the total volume excised to achieve negative margins were evaluated by multivariable analysis, by surgeon, and by tumor size and presence of extensive intraductal component (EIC).

Results

A total of 555 patients were identified, as follows: perpendicular, 140; tangential, 124; and cavity shave, 291. The tangential method had a higher rate of positive margins at first excision than the perpendicular and cavity-shave methods (49, 15, 11 %, respectively; p < 0.0001). Median volumes to achieve negative margins were similar (55 ml perpendicular; 64 ml tangential; 62 ml cavity shave; p = 0.24). Four of six surgeons had the lowest rate of positive margins with the cavity-shave method, which was significant when compared to the tangential method (p < 0.0001) but not the perpendicular method (p = 0.37). The volume excised by the three methods varied by surgeon (p < 0.0001). The perpendicular method was optimal for T1 tumors without EIC; the cavity-shave method tended to be superior for T2–T3 tumors and/or EIC.

Conclusions

Although the cavity-shave method may decrease the rates of positive margins, its effect on volume is variable among surgeons and may result in an increase in the total volume excised for some surgeons and for small tumors without EIC.     

The P3 Event-Related Potential is a Biomarker for the Efficacy of Vagus Nerve Stimulation in Patients with Epilepsy

Currently, the mechanism of action of vagus nerve stimulation (VNS) is not fully understood, and it is unclear which factors determine a patient’s response to treatment. Recent preclinical experiments indicate that activation of the locus coeruleus noradrenergic system is critical for the antiepileptic effect of VNS. This study aims to evaluate the effect of VNS on noradrenergic signaling in the human brain through a noninvasive marker of locus coeruleus noradrenergic activity: the P3 component of the event-related potential. We investigated whether VNS differentially modulates the P3 component in VNS responders versus VNS nonresponders. For this purpose, we recruited 20 patients with refractory epilepsy who had been treated with VNS for at least 18 months. Patients were divided into 2 groups with regard to their reduction in mean monthly seizure frequency: 10 responders (>50 %) and 10 nonresponders (≤50 %). Two stimulation conditions were compared: VNS OFF and VNS ON. In each condition, the P3 component was measured during an auditory oddball paradigm. VNS induced a significant increase of the P3 amplitude at the parietal midline electrode, in VNS responders only. In addition, logistic regression analysis showed that the increase of P3 amplitude can be used as a noninvasive indicator for VNS responders. These results support the hypothesis that activation of the locus coeruleus noradrenergic system is associated with the antiepileptic effect of VNS. Modulation of the P3 amplitude should be further investigated as a noninvasive biomarker for the therapeutic efficacy of VNS in patients with refractory epilepsy.     

国际医学杂志编辑委员会关于临床试验注册的声明

无私和信任是人体试验研究的核心。自愿参加研究的受试者是无私的,因为他们相信自己的参与将为他人健康的改善做出贡献,也相信研究者会尽最大努力减少受试者的风险。由于受试者的无私和信任,临床研究才成为可能,因此研究机构有义务使临床研究的实施符合伦理学要求,并诚实地报道研究结果。而诚实的报道首先需要知道所有现存的临床研究,即使其结果对赞助方不利。     

Location of Lymph Node Involvement in Patients with Esophageal Adenocarcinoma Predicts Survival

Background

The location of positive lymph nodes has been abandoned in the seventh classification of the TNM staging system for esophageal adenocarcinoma. The present study evaluates whether distribution of involved nodes relative to the diaphragm in addition to TNM 7 further refines prediction.

Methods

Pathology reports of patients who underwent esophagectomy between 2000 and 2008 for adenocarcinoma of the esophagus were reviewed and staging was performed according to the seventh UICC-AJCC staging system. In addition, lymph node involvement of nodal stations above and below the diaphragm was investigated by endoscopic ultrasonography (EUS) in a separate cohort of patients who were scheduled for esophagectomy between 2008 and 2009 at two institutions. Survival was calculated by the Kaplan–Meier method, and multivariate analysis was performed with a Cox regression model.

Results

Some 327 patients who had undergone esophagectomy for cancer were included. Multivariate analysis revealed that patients with from three to six involved lymph nodes in the resection specimen on both sides of the diaphragm had a twofold higher chance of dying compared to patients with the same number of involved lymph nodes on one side of the diaphragm. EUS assessment of lymph node metastases relative to the diaphragm in 102 patients showed that nodal involvement on both sides of the diaphragm was associated with worse survival than when nodes on one side or no nodes are involved [HR (95 % CI) 2.38 (1.15–4.90)].

Conclusions

A combined staging system that incorporates distribution of lymph nodes relative to the diaphragm refines prognostication after esophagectomy as assessed in the resected specimen and pretreatment as assessed by EUS. This improved staging has the potential to have a great impact on clinical decision making as to whether to embark upon potentially curative or palliative treatments.     

SILS Sigmoidectomy Versus Multiport Laparoscopic Sigmoidectomy for Diverticulitis

Background and Objectives:

In this single-institution study, we aimed to compare the safety, feasibility, and outcomes of single-incision laparoscopic sigmoidectomy (SILSS) with multiport laparoscopic sigmoidectomy (MLS) for recurrent diverticulitis.

Methods:

Between October 2011 and February 2013, 60 sigmoidectomies were performed by the same surgeon. Forty patients had a MLS and 20 patients had a SILSS. Outcomes were compared.

Results:

Patient characteristics were similar. There was no difference in morbidity, mortality or readmission rates. The mean operative time was longer in the SILSS group (P = .0012). In a larger proportion of patients from the SILSS group, 2 linear staplers were needed for transection at the rectum (P = .006). The total cost of disposable items was higher in the SILSS group (P < .0001). No additional ports were placed in the SILSS group. Return to bowel function or return to oral intake was faster in the SILSS group (P = .0446 and P = .0137, respectively). Maximum pain scores on postoperative days 1 and 2 were significantly less for the SILSS group (P = .0014 and P = .047, respectively). Hospital stay was borderline statistically shorter in the SILSS group (P = .0053). SILSS was also associated with better cosmesis (P < .0011).

Conclusion:

SILSS is feasible and safe and is associated with earlier recovery of bowel function, a significant reduction in postoperative pain, and better cosmesis.