Surgical repair of parastomal bulging: a retrospective register-based study on prospectively collected data

AIM

The aim of this work was to examine (1) the incidence of primary repair, (2) the incidence of recurrent repair and (3) the types of repair performed in patients with parastomal bulging.

METHOD

Prospectively collected data on parastomal bulging from the Danish Stoma Database were linked to surgical data on repair of parastomal bulging from the Danish National Patient Register. Survival statistics provided cumulative incidences and time until primary and recurrent repair.

RESULTS

In the study sample of 1016 patients with a permanent stoma and a parastomal bulge, 180 (18%) underwent surgical repair. The cumulative incidence of a primary repair was 9% [95% CI (8%; 11%)] within 1 year and 19% [95% CI (17%; 22%)] within 5 years after the occurrence of a parastomal bulge. We found a similar probability of undergoing primary repair in patients with ileostomy and colostomy. For recurrent repair, the 5-year cumulative incidence was 5% [95% CI (3%; 7%)]. In patients undergoing repair, the probability was 33% [95% CI (21%; 46%)] of having a recurrence requiring repair within 5 years. The main primary repair was open or laparoscopic repair with mesh (43%) followed by stoma revision (39%). Stoma revision and repair with mesh could precede or follow one another as primary and recurrent repair. Stoma reversal was performed in 17% of patients.

CONCLUSION

Five years after the occurrence of a parastomal bulge the estimated probability of undergoing a repair was 19%. Having undergone a primary repair, the probability of recurrent repair was high. Stoma reversal was more common than expected.

Validation of the Danish SARC-F in Hospitalized, Geriatric Medical Patients

OBJECTIVES

Validation of the Danish version of the SARC-F (Strength, Assistance in walking, Rise from a chair, Climb stairs, and Falls) for hospitalized geriatric medical patients, compared against the original EWGSOP (European Working Group on Sarcopenia in Older People) and revised EWGSOP2 definition for sarcopenia. Additionally, investigation of the ability of SARC-F to individually identify low strength/function and muscle mass.

DESIGN

Cross-sectional analysis of data from an RCT.

SETTING

Hospital, Medical Department.

PARTICIPANTS

122 geriatric medical patients (65.6% women) ≥ 70 years of age with mixed medical conditions.

MEASUREMENTS

SARC-F screening, diagnostic assessment of sarcopenia (hand-grip strength, muscle mass measured by dual-frequency bio-impedance analysis, and 4-m usual gait speed).

RESULTS

The prevalence of risk of sarcopenia (SARC-F ≥ 4) was 48.3%, while it was diagnosed in 65.8% and 21.7%, with EWGSOP and EWGSOP2, respectively. The sensitivity, specificity, positive predictive value, negative predictive value according to EWGSOP were 50.0 %, 53.7 %, 67.2% and 36.1%, while they were 53.8 %, 53.2 %, 24.1% and 80.6%, according to EWGSOP2 (all participants). The ability of SARC-F to predict reduced strength, function, and muscle mass was modest. There was a significant negative linear, yet weak, relationship between total SARC-F score and hand-grip strength (R2=0.033) and 4-m gait speed (R2=0.111), but not muscle mass (R2=0.004).

CONCLUSION

SARC-F does not seem to be a suitable screening tool for identifying and excluding non-sarcopenic geriatric patients. Furthermore, the SARC-F score was more strongly correlated with reduced muscle strength and physical function than with low muscle mass.

Incidence and risk factors for parastomal bulging in patients with ileostomy or colostomy: a register-based study using data from the Danish Stoma Database Capital Region

AIM

The aim was to investigate the incidence and risk factors for parastomal bulging, a clinically important complication, in patients with an ileostomy or colostomy.

METHOD

The Danish Stoma Database Capital Region prospectively collects data on patients with a stoma up to a year after surgery. Stoma care nurses clinically assessed the main outcome, parastomal bulging. We linked data from the Stoma Database to data from the Danish Anaesthesia Database. Cumulative incidence of parastomal bulging over the first year was calculated with death and stoma reversal as competing risks. Risk factors were investigated using an exploratory approach.

RESULTS

In a study population of 5019, the cumulative incidence (with competing risks) of parastomal bulging was 36.2% at 400 days after surgery. Age, colostomy, male gender, alcohol consumption and laparoscopy were associated with an increased risk of parastomal bulging. Compared with cancer, inflammatory bowel disease was associated with a lower risk of parastomal bulging, and diverticulitis was associated with a higher risk. Peristomal mesh and stomas placed through a separate incision were associated with a reduction in risk. There was neither increased nor decreased risk of parastomal bulging for body mass index, American Society of Anesthesiologists score, smoking status, emergency surgery and preoperative stoma site marking.

CONCLUSION

Parastomal bulging is a common complication affecting one in three patients within 1 year of surgery. Along with previous findings, there is now considerable evidence for age and colostomy as being risk factors for parastomal bulging.

Slide-based ergometer rowing: effects on force production and neuromuscular activity

Force production profile and neuromuscular activity during slide-based and stationary ergometer rowing at standardized submaximal power output were compared in 14 male and 8 female National Team rowers. Surface electromyography (EMG) was obtained in selected thoracic and leg muscles along with synchronous measurement of handle force and rate of force development (RFD). Compared to stationary conditions, slide-based peak force decreased by 76 (57-95) N (mean 95% CI) in males (P < 0.001) and 20 (8-31) N (P < 0.05) in females. Stroke rate increased (+10.7%) and late-phase RFD decreased (-20.7%) in males (P < 0.05). Neuromuscular activity in m. vastus lateralis decreased in the initial drive phase from 59% to 51% of EMG max in males and from 57% to 52% in females (P < 0.01-0.05), while also decreasing in the late recovery phase from 20% to 7% in males and 17% to 7% in females (P < 0.01). Peak force and maximal neuromuscular activity in the shoulder retractors always occurred in the second quartile of the drive phase. In conclusion, peak force and late-phase RFD (males) decreased and stroke rate increased (males) during slide-based compared to stationary ergometer rowing, potentially reducing the risk of overuse injury. Neuromuscular activity was more affected in leg muscles than thoracic muscles by slide-based ergometer rowing.

Exercise-induced rib stress fractures: potential risk factors related to thoracic muscle co-contraction and movement pattern

The etiology of exercise-induced rib stress fractures (RSFs) in elite rowers is unclear. The purpose of the study was to investigate thoracic muscle activity, movement patterns and muscle strength in elite rowers. Electromyographic (EMG) and 2-D video analysis were performed during ergometer rowing, and isokinetic muscle strength was measured in seven national team rowers with a history of RSF and seven matched controls (C). RSF displayed a higher velocity of the seat in the initial drive phase (RSF: 0.25+/-0.03, 0.25 (0.15-0.33) m/s vs C: 0.15+/-0.06, 0.18 (-0.11-0.29) m/s P=0.028) (Mean+/-SEM, median and range). Further, RSF had greater co-contraction of m. serratus anterior and m. trapezius in the mid-drive phase (RSF: 47.5+/-3.4, 48.5 (35.8-60.2)% EMG signal overlap vs C: 30.8+/-6.5, 27.0 (11.2-61.6)%P=0.043). In addition, the RSF subjects showed a lower knee-extension to elbow-flexion strength ratio (RSF: 4.2+/-0.22, 4.3 (3.5-5.1) vs C: 4.8+/-0.16, 5.0 (4.2-5.3) P=0.043), indicating stronger arms relative to legs compared with controls. In conclusion, increased thoracic muscle co-contraction, altered movement patterns and reduced leg/arm strength ratio were observed in the RSF subjects, which may all predispose toward an increased risk of RSF.

Managing job strain: a randomized, controlled trial of an intervention conducted by mail and telephone

A randomized, clinical intervention focused on alleviating job strain was conducted over 6 months by mail and/or telephone with a total of 136 employees of Bank of America. Both the mail and mail plus telephone interventions evidenced positive results, with the mail plus telephone intervention being the more effective. Given the relative low cost of such mediated interventions, the results provide a basis for the further development of interventions that may demonstrate both clinical and cost effectiveness.

Improved peptide mapping using phytic acid as ion-pairing buffer additive in capillary electrophoresis

By digestion of the highly basic polypeptide aprotinin or bovine pancreatic trypsin inhibitor (BPTI) with endoproteinase Lys-C after unfolding, reduction and pyridylethylation, five fragments are obtained. These fragments are separated by free solution capillary electrophoresis using a phosphate buffer at neutral pH. The effect of the ion-pairing buffer additive phytic acid on the separation was investigated. It is shown that phytic acid through ion-pair formation influences the mobility of only those peptide fragments having a net positive charge at the pH of the separation buffer. The affinity of phytic acid to the peptides correlates with their isoelectric point and the charge to mass ratios. Hence, by changing the concentration of phytic acid, it is possible to manipulate the migration order and the separation of the peptides.

Synthesis of stereoisomers and isoforms of a tryptic heptapeptide fragment of human growth hormone and analysis by reverse-phase HPLC and capillary electrophoresis

The amino acid sequence Asn-Gly has at pH 7 a tendency to induce deamidation of asparagine to aspartic acid via the formation of a cyclic imide. This imide opens up to yield Asp-Gly or the isoaspartic acid (isoAsp) form, isoAsp-Gly. Both isomers may be found in their L-form or D-form. Like Asn-Gly, the sequence Asp-Gly has a tendency for isomerization and racemization via the formation of a cyclic imide intermediate. When human growth hormone is digested with trypsin, one of the fragments is a heptapeptide (amino acid residues 128-134) containing the amino acid sequence Asp-Gly (amino acid residues 130 and 131). This heptapeptide, as well as stereoisomers and isoforms where L-Asp was replaced by D-Asp, L-isoAsp, D-isoAsp or the L-cyclic imide, respectively, has been synthesized and used as a standard to achieve separation of the five forms by capillary electrophoresis and by reverse-phase HPLC. Capillary electrophoresis analysis was performed in uncoated capillaries by the use of aspartic acid/cyclodextrin buffers at low pH. The elution order of the aspartic-acid-containing heptapeptides was D-Asp, L-Asp, L-isoAsp, D-isoAsp and L-cyclic imide. Reverse-phase HPLC analysis was performed on a C18 column by the use of a shallow acetonitrile gradient in trifluoroacetic acid/water. The elution order was D-isoasp, L-isoASp, L-Asp, D-Asp and L-cyclic imide. Human growth hormone samples were degraded by incubation at high temperature and analyzed for their potential content of isomerization and racemization products. Only L-forms of aspartic acid and isoaspartic acid of the heptapeptide fragment were found.

Effective ion-pairing for the separation of basic proteins in capillary electrophoresis

The addition of the sodium salt of phytic acid to the separation buffer (pH's 6.0-9.5) has allowed the analysis of a number of basic proteins (pI's > 9) by capillary electrophoresis. The method of analysis is simple and leads to considerable improvement in peak shape. Some very basic proteins, totally adsorbed onto the capillary fused silica surfaces in the presence of buffer only, can be analysed as sharp signals when this polyanionic species is included in the running electrolyte. These improvements in analysis are thought to arise as a result of the suppression of coulombic interactions between these positively charged proteins (ion-paired to phytic acid) and the negatively charged silanol groups on the inner wall of the capillary.

Using capillary electrophoresis in the optimization of a carboxypeptidase Y catalyzed transpeptidation reaction

A peptide amide, R-Arg-NH2, was produced by carboxypeptidase Y (CPDY)-catalyzed transpeptidation of a peptide, R-Ala-OH in presence of a large excess of Arg-NH2. Baseline separation of R-Ala-OH and R-Arg-NH2 was achieved by free solution capillary electrophoresis (CE) analysis. With CE the reactions could be closely followed with an analysis frequency of 3-6 h-1. Due to a low consumption of sample per CE analysis (1-5 nL introduced, 5-6 microL in the sample vial), the reactions were performed in 100 and 250 microL volumes. Consequently, the optimization experiments consumed limited amounts of enzyme and substrate only. At optimized experimental conditions approximately 90% conversion of the starting peptide, R-Ala-OH, to R-Arg-NH2 was achieved.

Capillary electrophoretic determination of the protease Savinase in cultivation broth

The highly basic washing enzyme Savinase and various analogues were analysed by micellar electrokinetic chromatography (MEKC) and electrophoresis. Broth samples were withdrawn during the cultivation of Savinase by recombinant microorganisms. Savinase peak areas obtained by MEKC-electrophoretic analysis were normalized with respect to migration time and compared with traditional enzyme activity measurements. The electropherograms indicated thermal degradation of the Savinase molecule at high field strengths. Baseline separation of Savinase and two analogues was achieved.

Identification of aprotinin degradation products by the use of high-performance capillary electrophoresis, high-pressure liquid chromatography and mass spectrometry

A preparation of bovine aprotinin, bovine pancreatic trypsin inhibitor, was subjected to high-performance capillary electrophoresis (HPCE) analysis and the purity was calculated to be approximately 80%. The two dominating contaminants were integrated to approximately 7% each as compared to the intact molecule. Characterization by high-pressure liquid chromatographic (HPLC) and mass spectrometric analysis was carried out on digests of the reduced and alkylated molecules. The contaminants were identified as truncated aprotinin, missing one and two amino acids, respectively, at the C-terminus. No such structures were identified in similar amounts in preparations of recombinant aprotinin by HPLC or HPCE.