Magseed localisation of non-palpable breast lesions: experience from a single centre

AIM

To prospectively analyse patients undergoing magnetic seed (Magseed) localisation (MSL) to evaluate the outcome, and to retrospectively compare re-excision rates for MSL with previous wire-guided localisation (WGL) to assess the hypothesis that the introduction of MSL may lead to a lower re-excision rate.

MATERIALS AND METHODS

MSL commenced at University Hospital Crosshouse in December 2017. No other changes were made to radiological or surgical practice during this time. Data were collected prospectively on all patients undergoing MSL between December 2017 and December 2019, in a single breast unit. Data were gathered retrospectively on patients who had undergone localised breast procedures between January 2016 and December 2019 for comparison of re-excision rates.

RESULTS

Two hundred and fifty-five patients underwent MSL surgery between December 2017 and December 2019. Of those, 98% (n=250) patients underwent successful MSL at the first attempt. The Magseed was identified intraoperatively in 100% patients and surgical excision was performed. The re-excision rate reduced from 18.9% in 2016/2017, to 11.6% in 2018/2019 (p=0.098).

CONCLUSION

In conclusion, Magseed localisation has proved to be a safe and effective way of localising breast lesions, with the advantage of high accuracy. The reduction in re-excision rates at University Hospital Crosshouse with the introduction of Magseed® localisation is a potential benefit, which requires further study.

Multivariate analysis of factors influencing the results of restorative proctocolectomy

Univariate and multivariate analysis has been used to assess the influence of 14 variables on the results of 65 consecutive ileoanal pouch procedures over 5 years. There were 9 failures requiring intubation, ileosomy or pouch excision. There was a significant association between failure and pelvic sepsis (p less than 0.05; n = 8), endoanal mucosectomy (p less than 0.05; n = 7), preservation of a long rectal cuff (p less than 0.05; n = 5) and lack of experience with the operation (p less than 0.05; n = 8). Of 49 patients with preoperative evidence of ulcerative colitis, 3 are now known to have Crohn's disease. The only factor having a significant adverse influence on complications was endoanal mucosectomy (p less than 0.01). Functional outcome was significantly impaired in patients who developed pelvic sepsis (p less than 0.001), a post-operative fistula (p less than 0.05) and who had an endoanal mucosectomy (p less than 0.05). Success with ileo-anal pouch reconstruction increases with experience. Avoidance of sepsis is associated with a lower failure rate, improved functional results and reduced hospital stay. Preliminary colectomy is also advised to exclude Crohn's disease if the diagnosis is in question.

Multivariate analysis of factors influencing the results of restorative proctocolectomy

Univariate and multivariate analyses have been used to assess the influence of 14 variables on the results of 65 consecutive ileoanal pouch procedures over 5 years. There were nine failures requiring intubation, ileostomy or pouch excision. There was a significant association between failure and pelvic sepsis (P less than 0.05, n = 8), endoanal mucosectomy (P less than 0.05, n = 7), preservation of a long rectal cuff (P less than 0.05, n = 5) and lack of experience with the operation (P less than 0.05, n = 8). Of 49 patients with preoperative evidence of ulcerative colitis, three are now known to have Crohn's disease. Functional outcome was significantly impaired in patients who developed pelvic sepsis (P less than 0.01) or a postoperative fistula (P less than 0.05), and who had an endoanal mucosectomy (P less than 0.05). Success with ileoanal pouch reconstruction increases with experience. Avoidance of sepsis is associated with a lower failure rate, improved functional results and reduced hospital stay. Preliminary colectomy is also advised to exclude Crohn's disease if the diagnosis is in question.

Vertex analysis of neural tree structures containing trichotomous nodes

Vertex analysis defines dichotomous networks in terms of the relative frequencies of pendant (Vp) and nodal (Vd) vertices. Va, Vb and Vc comprise the 3 classes of Vd which connect 2, 1 and 0 Vp respectively. The vertex ratio (VR) of Va/Vb may be used to define topology since Va and Vc approach equality in large networks. The introduction of trichotomous nodes (Vt, comprising Va', Vb', Vc' and Vd', connecting 3, 2, 1 and 0 Vp) confounds vertex analysis in as much as the values of VR must be recalculated to maintain the definition of topology. Each Vt is equivalent to 2Vd. Va', Vc' and Vd' may be unequivocally transformed into Va + Vb; Vb + Vc; and 2Vc respectively. However, Vb' potentially contains Va, Vb and Vc in proportions which must be arbitrarily set, since the mode of growth only determines the frequencies of Vt and not their transformation into Vd pairs. We have assumed that all possible pairs of transformed Vb' are equally likely and, accordingly, Vb' is equivalent to Va/3 + 4Vb/3 + Vc/3. The values of VR for different modes of growth, featuring different frequencies of Vt, may thus be obtained by computer growth simulation. The mode of growth of observed networks may thereby be ascertained from VR, providing all Vt are detectable in the tree.

Vertex analysis of Purkinje cell dendritic trees in the cerebellum of the rat

All networks are made up of vertices (points interconnected by segments), which include terminals interconnected by terminal segments, nodes interconnected by link segments and the root point connected to the tree by the root segment. All nodes may be classified into unique types according to the number of terminal and link segments they drain. For example, there are three distinct dichotomous nodes, a 'primary' node draining two terminal segments, a 'secondary' node draining one terminal segment and a link segment, and a 'tertiary' node draining two link segments. The numbers of primary and tertiary nodes approximate to equality in large networks and thus the ratio of primary to secondary nodes defines topology. All higher order nodes ( trichotomous and beyond) may be resolved into dichotomous forms and incorporated into the analysis. Different forms of growth may thus be analysed by comparing the frequency distributions of nodes with those generated by computer simulated growth models. Moreover, all vertices can be ordered so that metrical parameters are easily incorporated and the hierarchical arrangements of vertices of different order discerned. The dendritic trees of 48 Purkinje cells, taken from folia along the primary fissure, were analysed using vertex analysis. The mean number of segments in Purkinje cell trees was 881 +/- 23 (s.e.) and mean total dendritic length 7959 +/- 233 (s.e.) micrometers. Segment lengths were longest over proximal segments but over most of the tree segment lengths were constant at 10 +/- 0.2 (s.e.) micrometers. Vertex, segment and terminal frequency distributions of equivalent orders were all normal with a slight positive skew. Peak frequencies were recorded at the 12th equivalent order. The mean primary/secondary nodal vertex ratio was 0.93 and the proportion of trichotomous branch points in the tree was 5%. Comparison of the frequency distribution of all vertices with computer generated models showed that growth of the Purkinje cell was most closely simulated by a random terminal growth model, incorporating 5% trichotomy , in which the branching of high order terminals was more likely than low order terminals. It was concluded that growth of the Purkinje cell tree could proceed by random terminal branching with growth occurring preferentially over a front composed of terminals that are ascending through a corridor in the molecular layer whose margins are defined by neighbouring trees.

Multivariate analysis of clinical and operative findings associated with bilary sepsis

A cluster analysis of 17 preoperative and 10 operative variables has been undertaken from a prospective study of 181 patients undergoing operations on the biliary tract in order to identify those with organisms in the bile who would therefore benefit from prophylactic antibiotic cover. The analysis defined populations of high risk (45 patients) and low risk (136 patients) in which the incidence of infected bile was 67 and 19 per cent respectively (P less than 0-001). Eight variables were more common in the high risk than in the low risk group (P less than 0-001). These "high risk factors" were: jaundice at operation, recent rigoors, emergency operation or one within 4 weeks of an emergency admission, age over 70 years, previous biliary operation, common duct obstruction and stones in the bile duct. In 67 patients where one or more "high risk factors" was present, the bile contained organisms in 37 (53 percent); when 4 "high risk factors" occurred in the same patient (16 cases) biliary organisms were isolated in 14(87 per cent). We conclude that the presence of one or more "high risk factors" indicates a patient in whom prophylactic antibiotics would be advised during an operation on the biliary tract.