Long-term bowel functional outcomes following anal sphincter-preserving surgery for upper and middle rectal cancer: a single-center longitudinal study

PURPOSE

Despite advances in neoadjuvant chemoradiotherapy and anal sphincter-preserving surgery for rectal cancer, bowel dysfunction is still unavoidable and negatively affects patients' quality of life. In this longitudinal study, we aimed to investigate the changes in bowel function with follow-up time and the effect of neoadjuvant chemoradiotherapy on bowel function following low anterior resection for rectal cancer.

METHODS

In this study, 171 patients with upper or middle rectal cancer who underwent low anterior resection between 2012 and 2018 were included. Bowel function was assessed longitudinally with Memorial Sloan Kettering Cancer Center Bowel Function Instrument and Wexner scores every 6 months after restoration of bowel continuity. Patients with at least 2 follow-up visits were included.

RESULTS

Overall, 100 patients received neoadjuvant chemoradiotherapy. Urgency, soilage, and fecal incontinence were noted within 24 months in the patients treated with neoadjuvant chemoradiotherapy. After 2 years of follow-up, significant bowel dysfunction and fecal incontinence were observed in the neoadjuvant chemoradiotherapy group. Low tumor level and neoadjuvant chemoradiotherapy were associated with delayed bowel dysfunction.

CONCLUSION

Neoadjuvant chemoradiotherapy in combination with low tumor level was significantly associated with delayed bowel dysfunction even after 2 years of follow-up. Therefore, careful selection and discussion with patients are paramount.

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

BACKGROUND

Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks.

METHODS

The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned.

RESULTS

A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31).

CONCLUSION

Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov).

Multicenter validation of the PREDICT score for prediction of local recurrence after total mesorectal excision of rectal cancer

BACKGROUND

Total mesorectal excision (TME) is the gold standard treatment for rectal cancer. Although TME has managed to decrease the rates of local recurrence after rectal cancer resection, local recurrence is still recorded at varying rates. The present study aimed to validate the PREDICT score in the prediction of local recurrence of rectal cancer after TME with curative intent.

METHODS

This was a retrospective multicenter study on patients with nonmetastatic low or middle rectal cancer who underwent TME. The total PREDICT score was calculated for every patient and related to the onset of local recurrence. According to the final score, patients were allocated to one of three risk groups: low, moderate, and high, and the rates of local recurrence in each group were calculated and compared.

RESULTS

The present study included 262 patients (50.4% males) with a mean age of 47.1 years. The overall local recurrence rate was 12.6%. 29.4% of patients were in the low-risk group, 63.7% in the moderate-risk group, and 6.9% in the high-risk group. The local recurrence rate was 3.9% (95% confidence interval [CI]: 0.8-10.9) in the low-risk group, 13.2% (95% CI: 8.4-19.3) in the moderate risk group, and 44.4% (95% CI: 21.5-69.2) in the high-risk group (p < 0.0001). The sensitivity of the PREDICT score was 72.7%, the specificity was 88.1%, and the accuracy was 86.3%.

CONCLUSIONS

The PREDICT score had good diagnostic accuracy in the prediction of local recurrence after TME and a good discriminatory ability in the differentiation between patients at different risks to develop local recurrence.

Ultrasound-guided versus laparoscopic-guided subcostal transversus abdominis plane (TAP) block versus No TAP block in laparoscopic cholecystectomy; a randomized double-blind controlled trial

BACKGROUND

Transversus abdominis plane (TAP) block is an effective modality for the control of immediate postoperative pain. The present randomized trial aimed to assess the efficacy of ultrasound-guided subcostal TAP (USTAP) and laparoscopic subcostal TAP (LSTAP) block as compared to standard care without TAP block after laparoscopic cholecystectomy.

METHODS

This was a prospective, randomized, controlled trial on patients who underwent laparoscopic cholecystectomy. Patients were equally randomized to one of three groups: USTAP, LSTAP, and control group (no TAP block). The main outcome measures were pain scores and analgesic consumption within the first 24 h postoperatively, postoperative nausea and vomiting (PONV), time to ambulation, time to first flatus, and adverse effects of TAP block.

RESULTS

The trial included 110 patients (90% females) with a mean age of 40.9 ± 11.7 years. Both USTAP and LSTAP block groups were associated with significantly lower pain scores at 2, 6, 12, and 24 h postoperatively, lower cumulative dose of paracetamol, less PONV, and shorter time to flatus than the control group. USTAP and LSTAP block were associated with similar pain scores at all time points, similar analgesic requirements, a similar incidence of PONV, and comparable time to first ambulation and time to first flatus. No adverse effects related to TAP block were recorded.

CONCLUSIONS

TAP block is a safe and effective method for pain control and improving recovery after laparoscopic cholecystectomy. Both USTAP and LSTAP blocks were equally effective in terms of pain relief, analgesic requirements, PONV, return of bowel function, and time to ambulation.

Efficacy and Safety of Non-Operative Management of Uncomplicated Acute Appendicitis Compared to Appendectomy: An Umbrella Review of Systematic Reviews and Meta-Analyses

BACKGROUND

Non-operative management (NOM) of uncomplicated acute appendicitis (AA) has been introduced as an alternative to appendectomy. This umbrella review aimed to provide an overview of the efficacy and safety of NOM of uncomplicated AA in the published systematic reviews.

METHODS

This umbrella review has been reported in line with the PRISMA guidelines and umbrella review approach. Systematic reviews with and without meta-analyses on the efficacy of NOM of AA were analyzed. The quality of the reviews was assessed with the AMSTAR 2 tool. The main outcomes measures were the treatment failure and complication rates of NOM and hospital stay as compared to appendectomy.

RESULTS

Eighteen systematic reviews were included to this umbrella review. Eight reviews documented higher odds of failure with NOM, whereas two reviews revealed similar odds of failure. Six reviews reported lower odds of complications with NOM, six reported similar odds, and one reported lower odds of complications with surgery. Eight reviews reported similar hospital stay between NOM and appendectomy, one reported longer stay with NOM and another reported shorter stay with NOM. Pooled analyses showed that NOM was associated with higher treatment failure overall, in children-only, adults only, and RCTs-only meta-analyses. NOM was associated with lower complications overall, yet children-only and RCTs-only analyses revealed similar complications to surgery. NOM was associated with shorter stay in the overall and adult-only analysis, but not in the children-only analysis.

CONCLUSIONS

NOM of AA is associated with higher treatment failure, marginally lower rate of complications and shorter stay than appendectomy.

Neorectal Mucosal Prolapse After Intersphincteric Resection for Low-Lying Rectal Cancer: A Case Report

Radical resection for low rectal cancer is the mainstay among the treatment modalities. Intersphincteric resection (ISR) is considered a relatively new but effective surgical treatment for low-lying rectal tumor. As the sphincter preserving techniques get popularized, we notice uncommon complication associated with it in the form of rectal mucosal prolapse. We presented 2 rare cases that developed neorectal mucosa prolapse after ISR a complication following low rectal cancer surgery. Although ISR is a safe and effective surgical technique for low rectal cancer, it should be considered to correct modifiable possible risk factors. Also, Delorme procedure is good option for management of neorectal mucosal prolapse.

Outcome of lateral pelvic lymph node dissection with total mesorectal excision in treatment of rectal cancer: A systematic review and meta-analysis

BACKGROUND

Total mesorectal excision is the gold standard treatment of mid- and low-lying rectal cancer. Lateral pelvic lymph node dissection has been suggested as an approach to decrease recurrence and improve survival. Our meta-analysis presented here aimed to review the current outcomes of lateral pelvic lymph node dissection and total mesorectal excision in comparison with total mesorectal excision alone.

METHODS

A systematic literature search querying electronic databases was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. We reviewed articles that reported the outcomes of lateral pelvic lymph node dissection combined with total mesorectal excision in comparison with total mesorectal excision alone. The main outcome measures were local recurrence, distant metastasis, overall and disease free-survival, and complications.

RESULTS

This systematic review included 29 studies of 10,646 patients. Of those patients, 39.4% underwent total mesorectal excision with lateral pelvic lymph node dissection. The median operation time for the lateral pelvic lymph node dissection + total mesorectal excision was significantly longer than total mesorectal excision alone (360 minutes versus 294.7 minutes, P = .02). Lateral pelvic lymph node dissection + total mesorectal excision was associated with higher odds of overall complications (odds ratio = 1.48, 95% confidence interval: 1.18-1.87, P < .001) and urinary dysfunction (odds ratio = 2.1, 95% confidence interval: 1.21-3.67, P = .008) than total mesorectal excision alone. Both groups had similar rates of male sexual dysfunction (odds ratio = 1.62, 95% confidence interval: 0.94-2.79, P = .08), anastomotic leakage (odds ratio = 1.15, 95% confidence interval: 0.69-1.93, P = .59), local recurrence (hazard ratio = 0.96, 95% confidence interval: 0.75-1.25, P = .79), distant metastasis (hazard ratio = 0.96, 95% confidence interval: 0.76-1.2, P = .72), overall survival (hazard ratio = 1.056, 95% confidence interval: 0.98-1.13, P = .13), and disease-free survival (hazard ratio = 1.02, 95% confidence interval: 0.97-1.07, P = .37).

CONCLUSION

Lateral pelvic lymph node dissection was not associated with a significant reduction of recurrence rates or improvement in survival as compared with total mesorectal excision alone; however, LPLND was associated with longer operation time and increased complication rate.

Does the timing of protective ileostomy closure post-low anterior resection have an impact on the outcome? A retrospective study

BACKGROUND

The optimal timing for ileostomy closure remains controversial, most of the surgeons are closing ileostomy after two to three months, although ileostomy closure considered a simple procedure, it can cause significant morbidity; this study aims to clarify any relation between the post-closure complications rate and the time from its creation to the repair.

METHOD

From January 2010 to December 2017, data retrieved for a 405 patients who had protective ileostomy closure after rectal cancer surgery, our sample has been enrolled into two arms, the first arm includes whose ileostomies closed at or before three months, and the second arm involved whose ileostomies closed after three months from the index surgery, statistical analysis was performed and compared in both arms, RESULT: The overall post-closure complications in our hospital was 23.7%, there was no significant difference between the overall complications rate for both early and late closure groups (26.8% and 22.7%) respectively (P = 0.499), The majority of the complications were intestinal obstruction, and superficial surgical site infection, there was no significant association between the interval to ileostomy reversal and the intestinal obstruction although it was higher in the late closure group, in the other hand the surgical site infection complication found to be significantly higher in the early closure group than the late closure group (15.4% Vs 5.1%) with (P = 0.002).

CONCLUSION

The duration between the creation of protective ileostomy and its reversal was not a significant independent predictor of post-closure complications rate.

A systematic review and meta-analysis of the safety and efficacy of fistula laser closure

BACKGROUND

Fistula laser closure (FiLaC) is a novel sphincter-saving technique for the treatment of fistula-in-ano. The aim of this study was to assess the safety and efficacy of the FiLaC procedure.

METHODS

Databases including PubMed/Medline, Scopus, Web of Science, and Embase were searched for articles assessing FiLaC. All studies including case series and comparative studies reporting the outcome of FiLaC in the treatment of fistula-in-ano were considered eligible. The main outcomes were healing rates of fistula laser closure, postoperative complications including incontinence, technical aspects of the procedure and failure of healing.

RESULTS

Seven studies were included. There were a total of 454 patients, 69.1% with a transsphincteric fistula-in-ano and 35% with recurrent disease. The median age of the patients was 43 years (range 18-83 years). The median operation time was 18.3 min (range 6-32 min). With a median follow-up of 23.7 months, the weighed mean rate of primary healing was 67.3% and the overall success when FiLaC was reused was 69.7%. The weighted mean rate of complications was 4%, all of them were minor complications and the weighted mean rate of continence affection was 1% in the form of minor soiling.

CONCLUSIONS

FiLaC may be considered an effective and safe sphincter-saving technique for the treatment of fistula-in-ano with an acceptable, low, complication rate. However, well-designed randomized control trials comparing FiLaC with other techniques are required to substantiate the promising outcomes reported in this review.

Oncologic safety and bowel function after ultralow anterior resection with or without intersphincteric resection for low lying rectal cancer: Comparative cross sectional study

BACKGROUND

Despite acceptable oncologic outcomes of sphincter preserving surgeries for low rectal cancer, bowel dysfunction occurs. This study aimed to compare the oncologic and functional bowel outcomes between ultralow anterior resection (ULAR) and intersphincteric resection (ISR) for low rectal cancer.

METHODS

One hundred sixty-four patients who underwent ULAR with or without ISR for low rectal cancer between December 2010 and May 2018 were included. The Wexner and Memorial Sloan Kettering Cancer Center (MSKCC) scores were used to evaluate the bowel function of patients. Overall survival (OS) and disease-free survival (DFS) were compared between patients.

RESULTS

The ISR group had higher incidence of major fecal incontinence than the ULAR group (75.9% vs 49.3%; P = .016). The median Wexner score decreased from 12 to 9 (P = .062) at 1-year follow-up. However, the frequency and urgency/soilage subscales of MSKCC score improved significantly in the ULAR group. ISR and follow-up interval less than 1-year significantly increased the major incontinence risk. The OS in the ULAR and ISR groups was 91.4% and 91.7%. Whereas the DFS in both groups was 79% and 79.2%, respectively.

CONCLUSION

ULAR and ISR are comparable in oncologic outcomes. Severe bowel dysfunctions and major incontinence were noted in ISR group. Careful selection of patients is mandatory.

Single-center Experience of 24 Cases of Tailgut Cyst

Purpose

Tailgut cysts are rare congenital or developmental lesions that arise from vestiges of the embryological hindgut. They are usually present in the presacral space. We report our single-center experience with managing tailgut cysts.

Methods

We conducted a retrospective analysis of 24 patients with tailgut cyst treated surgically at the Colorectal Surgery Department of Severance Hospital, Yonsei University, Seoul, South Korea, between 2007–2018.

Results

This study included 24 patients (18 females) with a median age of 51.5 years (range, 21–68 years). Ten cases were symptomatic and 14 were asymptomatic. Cysts were retrorectal in 21 patients. Cysts were below the coccyx level in 16 patients, opposite the coccyx in 6, and above the coccyx in 2. Cysts were supralevator in 5 patients, had a supra- and infralevator extension in 18 patients, and were infralevator in 1. Ten patients were managed using an anterior laparoscopic approach, 11 using a posterior approach, and 3 using a combined approach. Mean cyst size was 5.5 ± 2.7 cm. Postoperative complications were Clavien-Dindo (CD) classification grade II in 9 patients (37.5%) and CD grade III in 1 (4.2%). The posterior approach group showed the highest rate of complications (P = 0.021). Patients managed using a combined approach showed a larger cyst size (P < 0.001), longer operation times (P < 0.001), and a greater likelihood of tumor level above the coccyx (P = 0.002) compared to other approaches. The tumors of 2 male patients were malignant: 1 was a neuroendocrine tumor treated with radiotherapy, while the other was a closely followed adenocarcinoma. Median follow-up was 12 months (range, 1–66 months) with no recurrence.

Conclusion

Tailgut cysts are uncommon but can cause perineal or pelvic pain. Complete surgical excision via an appropriate approach according to tumor size, location, and correlation with adjacent pelvic floor muscles is the key treatment.

Outcome of laparoscopic ventral mesh rectopexy for full-thickness external rectal prolapse: a systematic review, meta-analysis, and meta-regression analysis of the predictors for recurrence

BACKGROUND

Laparoscopic ventral mesh rectopexy (LVMR) has proved effective in the treatment of internal and external rectal prolapse. The present meta-analysis aimed to determine the predictive factors of recurrence of full-thickness external rectal prolapse after LVMR.

METHODS

An organized, systematic search of electronic databases including PubMed/Medline, Embase, Scopus, and Cochran library was conducted in adherence to PRISMA guidelines. Studies that reported the outcome of LVMR in patients with full-thickness external rectal prolapse were included according to predefined criteria. A meta-regression analysis and sub-group meta-analyses were performed to recognize the patient and technical factors that were associated with higher recurrence rates.

RESULTS

Seventeen studies comprising 1242 patients of a median age of 60 years were included. The median operation time was 122.3 min. Conversion to open surgery was required in 22 (1.8%) patients. The weighted mean complication rate across the studies was 12.4% (95% CI 8.4-16.4) and the weighted mean rate of recurrence of full-thickness external rectal prolapse was 2.8% (95% CI 1.4-4.3). The median follow-up duration was 23 months. Male gender (SE = 0.018, p = 0.008) and length of the mesh (SE = - 0.007, p = 0.025) were significantly associated with full-thickness recurrence of rectal prolapse. The weighted mean rates of improvement in fecal incontinence and constipation after LVMR were 79.3% and 71%, respectively.

CONCLUSION

LVMR is an effective and safe option in treatment of full-thickness external rectal prolapse with low recurrence and complication rates. Male patients and length of the mesh may potentially have a significant impact on recurrence of rectal prolapse after LVMR.

Transanal hemorrhoidal dearterialization (THD) versus stapled hemorrhoidopexy (SH) in treatment of internal hemorrhoids: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Although conventional hemorrhoidectomy proved effective in treatment of hemorrhoidal disease, postoperative pain remains a vexing problem. Alternatives to conventional hemorrhoidectomy as transanal hemorrhoidal dearterialization (THD) and stapled hemorrhoidopexy (SH) were described. The present meta-analysis aimed to review the randomized trials that compared THD and SH to determine which technique is superior in terms of recurrence of hemorrhoids, complications, and postoperative pain.

METHODS

Electronic databases were searched for randomized trials that compared THD and SH for internal hemorrhoids. The PRISMA guidelines were followed when reporting this meta-analysis. The primary endpoint of the analysis was persistence or recurrence of hemorrhoidal disease. Secondary endpoints were postoperative pain, complications, readmission, return to work, and patients' satisfaction.

RESULTS

Six randomized trials including 554 patients (THD = 280; SH = 274) were included. The mean postoperative pain score of THD was significantly lower than SH (2.9 ± 1.5 versus 3.3 ± 1.6). 13.2% of patients experienced persistent or recurrent hemorrhoids after THD versus 6.9% after SH (OR = 1.93, 95%CI = 1.07-3.51, p = 0.029). Complications were recorded in 17.1% of patients who underwent THD and 23.3% of patients who underwent SH (OR = 0.68, 95%CI 0.43-1.05, p = 0.08). The average duration to return to work after THD was 7.3 ± 5.2 versus 7.7 ± 4.8 days after SH (p = 0.34). Grade IV hemorrhoids was significantly associated with persistence or recurrence of hemorrhoidal disease after both procedures.

CONCLUSION

THD had significantly higher persistence/recurrence rate compared to SH whereas complication and readmission rates, hospital stay, return to work, and patients' satisfaction were similar in both groups.

Systematic review of endoluminal vacuum-assisted therapy as salvage treatment for rectal anastomotic leakage

Background

Endoluminal vacuum-assisted therapy (EVT) has been introduced recently to treat colorectal anastomotic leakage. The aim of this study was to evaluate the safety and efficacy of EVT in the treatment of anastomotic leakage and rectal stump insufficiency after Hartmann's procedure.

Methods

A systematic search of MEDLINE, Scopus and Cochrane databases was performed using search terms related to EVT and anastomotic leakage or rectal stump insufficiency in line with the PRISMA checklist. Observational studies, RCTs and case series studies published to July 2017 were included. Primary outcomes of the review were the success of EVT, defined as complete or partial healing of the anastomotic defect and associated cavity, and the rate of stoma reversal after EVT. Secondary outcomes included the duration of treatment to complete healing, complications of treatment and the need for further intervention. A meta-analysis was conducted. The potential effect of clinical confounders on the failure of EVT was investigated using the random-effects meta-regression model.

Results

Of 476 articles identified, 17 studies reporting on 276 patients were ultimately included. The weighted mean rate of success was 85·3 (95 per cent c.i. 80·1 to 90·5) per cent, with a median duration from inception of EVT to complete healing of 47 (range 40-105) days. The weighted mean rate of stoma reversal across the studies was 75·9 (64·6 to 87·2) per cent. Twenty-five patients (9·1 per cent) required additional interventions after EVT. Thirty-eight patients (13·8 per cent) developed complications. The weighted mean complication rate across the studies was 11·1 (6·0 to 16·2) per cent. Variables significantly associated with failure included preoperative radiotherapy, absence of diverting stoma, complications and male sex.

Conclusion

EVT is associated with a high rate of complete healing of anastomotic leakage and stoma reversal. It is an effective option in appropriately selected patients with anastomotic leakage.

Management of acute uncomplicated diverticulitis without antibiotics: a systematic review, meta-analysis, and meta-regression of predictors of treatment failure

BACKGROUND

Diverticulitis is a common complication of diverticular disease of the colon. While complicated diverticulitis often warrants intervention, acute uncomplicated diverticulitis (AUD) is usually managed conservatively. The aim of the present review was to evaluate the efficacy and safety of conservative treatment of AUD without antibiotics compared to standard antibiotic treatment.

METHODS

A systematic literature review in compliance with PRISMA guidelines was conducted. Electronic databases including PubMed/Medline, Scopus, Embase and Cochrane central register of controlled trials were searched. Studies that assessed efficacy and safety of treatment of AUD without antibiotics were included. Outcome parameters were rates of treatment failure, recurrence of diverticulitis, complications and mortality, readmission to hospital, and need for surgery.

RESULTS

Nine studies including 2565 patients were included to the review. Of these patients, 65.1% were treated conservatively without antibiotics. Treatment failure was observed in 5.1% of patients not-given-antibiotic treatment versus 3.4% of those given antibiotic treatment. Recurrent diverticulitis occurred in 9.3% of patients in the non-antibiotic group versus 12.1% of patients in the antibiotic group. On meta-analysis of the studies, there were no significant differences between non-antibiotic and antibiotic treatment groups regarding rates of treatment failure (OR = 1.5, p = 0.06), recurrence of diverticulitis (OR = 0.81, p = 0.2), complications (OR = 0.56, p = 0.25), readmission rates (OR = 0.97, p = 0.91), need for surgery (OR = 0.59, p = 0.28), and mortality (OR = 0.64, p = 0.47). The only variable that was significantly associated with treatment failure in the non-antibiotic treatment group was associated comorbidities (standard error (SE) = - 0.07, 95% CI - 0.117 - 0.032; p < 0.001).

CONCLUSIONS

Treatment of AUD without antibiotics is feasible, safe, and effective. Adding broad-spectrum antibiotics to the treatment regimen did not serve to decrease treatment failure, recurrence, complications, hospital readmissions, and need for surgery significantly compared to non-antibiotic treatment.

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

BACKGROUND

Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.

METHODS

This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.

FINDINGS

Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p<0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05-2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p<0·001).

INTERPRETATION

Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication.

FUNDING

DFID-MRC-Wellcome Trust Joint Global Health Trial Development Grant, National Institute of Health Research Global Health Research Unit Grant.

A Systematic review and meta-analysis of the efficacy and safety of video-assisted anal fistula treatment (VAAFT)

BACKGROUND

Video-assisted anal fistula treatment (VAAFT) is a novel, minimally invasive technique for the treatment of fistula-in-ano (FIA). This review aimed to search the literature for the outcome of VAAFT regarding the recurrence and complication rates of the technique.

METHODS

A systematic literature search was conducted in compliance with the PRISMA screening guidelines. PubMed/MEDLINE and Scopus were searched for articles reporting the outcomes of VAAFT procedure from inception through April 2017. The main outcomes were patients' characteristics, technical aspects, operation time, recurrence, and complication rates.

RESULTS

Eleven studies (n = 788 patients) were included. The mean age of the patients was 39.5 years. 66.5% of patients had high or complex FIA and 18.4% underwent previous fistula surgery. The internal opening of the fistula was detected in 85.7% of patients. The mean operation time was 42 ± 14.2 min. The weighed mean rate of detection of internal opening was 93.3%. Recurrence occurred in 112 (14.2%) patients after a median follow-up of 9 months. Recurrence rates varied according to method of closure of internal opening from 15.3% after using staplers, 17.7% after suturing, to 25% after advancement flap. The weighted mean recurrence rate across the studies was 17.7%. The weighted mean complication rate was 4.8%.

CONCLUSION

VAAFT may be considered an effective diagnostic tool and a safe method for the treatment of complex and high FIA attaining satisfactory outcome and acceptably low complications. Recurrence after VAAFT may be related to previous fistula surgery and the method of closure of the internal opening.

Perineal resectional procedures for the treatment of complete rectal prolapse: A systematic review of the literature

BACKGROUND AND AIM

Several procedures for the treatment of complete rectal prolapse (CRP) exist. These procedures are performed via the abdominal or perineal approach. Perineal procedures for rectal prolapse involve either resection or suspension and fixation of the rectum. The present review aimed to assess the outcomes of the perineal resectional procedures including Altemeier procedure (AP), Delorme procedure (DP), and perineal stapled prolapse resection (PSR) in the treatment of CRP.

PATIENTS AND METHODS

A systematic search of the current literature for the outcomes of perineal resectional procedures for CRP was conducted. Databases queried included PubMed/MEDLINE, SCOPUS, and Cochrane library. The main outcomes of the review were the rates of recurrence of CRP, improvement in bowel function, and complications.

RESULTS

Thirty-nine studies involving 2647 (2390 females) patients were included in the review. The mean age of patients was 69.1 years. Recurrence of CRP occurred in 16.6% of patients. The median incidences of recurrence were 11.4% for AP, 14.4% for DP, and 13.9% for PSR. Improvement in fecal incontinence occurred in 61.4% of patients after AP, 69% after DP, and 23.5% after PSR. Complications occurred in 13.2% of patients. The median complication rates after AP, DP and PSR were 11.1%, 8.7%, and 11.7%, respectively.

CONCLUSION

Perineal resectional procedures were followed by a relatively high incidence of recurrence, yet an acceptably low complication rate. Definitive conclusions on the superiority of any procedure cannot be reached due to the significant heterogeneity of the studies.

91-Year-Old Allograft: Oldest Surviving Donor Heart Still Going: A Case Report

For patients with end-stage heart failure, heart transplantation remains one of the most successful therapies with excellent long-term survival rates. However, over the past few decades, there has been a worsening supply/demand mismatch given the rising epidemic of heart failure and the relatively fixed availability of donor hearts. In this case report, we describe the case of a 30-year-old woman who underwent transplantation with a 68-year-old donor heart and who has survived for 23 years without any major cardiac problems. To our knowledge, this patient has one of the oldest surviving donor hearts (91-year-old heart). Review of the latest guidelines and recent studies have demonstrated a gradual expansion of donor criteria to meet this critical shortage of donor organs.

Outcomes following repair of incarcerated and strangulated ventral hernias with or without synthetic mesh

Background

The use of synthetic mesh for ventral hernia repair under contaminated conditions is a controversial issue due to the considerable risk of surgical site infection (SSI). This study aimed to review the outcomes of repair of incarcerated and strangulated ventral hernias with or without synthetic mesh in compliance with established clinical guidelines regarding the incidence of SSI and hernia recurrence.

Methods

The records of patients with complicated ventral hernias who were treated with or without synthetic mesh repair were reviewed. Variables collected included the characteristics of patients and of ventral hernias, type of repair, and incidence of SSI and recurrence.

Results

One hundred twenty-two patients (56 males) of a mean age of 56 years were included. Fifty-two (42.6%) and 70 (57.4%) patients presented with incarcerated and strangulated ventral hernias, respectively. Sixty-six (54%) patients were treated with on-lay mesh repair, and 56 (46%) were managed with suture repair. Twenty-one patients required bowel resection. SSI was detected in eight (6.5%) patients. There was no significant difference between both groups regarding the incidence of SSI (7.5% for mesh group vs 5.3% for suture group). Recurrence occurred in seven patients. Median follow-up period was 24 months. The suture repair group had a significantly higher incidence of recurrence than the mesh group. Diabetes mellitus, previous recurrence, and intestinal resection were significant predictors for SSI.

Conclusion

Following established guidelines, synthetic mesh repair of incarcerated and strangulated ventral hernias attained lower recurrence rate, comparable incidence of SSI, and higher rate of seroma formation than suture repair.

Trial registration

Research Registry, researchregistry1891

Sensitivity and specificity of indocyanine green near-infrared fluorescence imaging in detection of metastatic lymph nodes in colorectal cancer: Systematic review and meta-analysis

This review aimed to determine the overall sensitivity and specificity of indocyanine green (ICG) near-infrared (NIR) fluorescence in sentinel lymph node (SLN) detection in Colorectal cancer (CRC). A systematic search in electronic databases was conducted. Twelve studies including 248 patients were reviewed. The median sensitivity, specificity, and accuracy rates were 73.7, 100, and 75.7. The pooled sensitivity and specificity rates were 71% and 84.6%. In conclusion, ICG-NIR fluorescence is a promising technique for detecting SLNs in CRC.

Predictive Factors for Small Intestinal and Colonic Anastomotic Leak: a Multivariate Analysis

Anastomotic leak (AL) is a serious complication of intestinal surgery with various predisposing factors. This study aims to assess several risk factors associated with AL after small intestinal and colonic anastomoses through a multivariate analysis. Two hundred twenty-four patients (126 males) with intestinal anastomosis of a median age of 44 years were reviewed. Independent factors associated with AL were male gender (OR = 2.59, P = 0.02), chronic liver disease (CLD) (OR = 8.03, P < 0.0001), more than one associated comorbidity (OR = 5.34, P = 0.017), anastomosis conducted as emergency (OR = 2.73, P = 0.012), colonic anastomosis (OR = 2.51, P = 0.017), preoperative leukocytosis (OR = 2.57, P = 0.015), and intraoperative blood transfusion (OR = 2.25, P = 0.037). Predicative factors significantly associated with AL were male gender, CLD, multiple comorbidities, emergent anastomoses, colonic anastomoses, preoperative leukocytosis, and intraoperative blood transfusion.

Outcomes of Renal Transplantation in HIV-1 Associated Nephropathy

Introduction

Several studies have demonstrated that renal transplantation in HIV positive patients is both safe and effective. However, none of these studies have specifically examined outcomes in patients with HIV-associated nephropathy (HIVAN).

Methods

Medical records of all HIV-infected patients who underwent kidney transplantation at Johns Hopkins Hospital between September 2006 and January 2014 were reviewed. Data was collected to examine baseline characteristics and outcomes of transplant recipients with HIVAN defined pathologically as collapsing focal segmental glomerulosclerosis (FSGS) with tubulo-interstitial disease.

Results and Discussion

During the study period, a total of 16 patients with HIV infection underwent renal transplantation. Of those, 11 patients were identified to have biopsy-proven HIVAN as the primary cause of their end stage renal disease (ESRD) and were included in this study. They were predominantly African American males with a mean age of 47.6 years. Seven (64%) patients developed delayed graft function (DGF), and 6 (54%) patients required post-operative dialysis within one week of transplant. Graft survival rates at 1 and 3 years were 100% and 81%, respectively. Acute rejection rates at 1 and 3 years were 18% and 27%, respectively. During a mean follow up of 3.4 years, one patient died.

Conclusions

Acute rejection rates in HIVAN patients in this study are higher than reported in the general ESRD population, which is similar to findings from prior studies of patients with HIV infection and ESRD of various causes. The high rejection rates appear to have no impact on short or intermediate term graft survival.

Poly(dimethylsiloxane) coatings for controlled drug release--polymer modifications

Modifications of endhydroxylated poly(dimethylsiloxane) (PDMS) formulations were studied for their ability to be applied onto tablet cores in a spray-coating process and to control drug release in zero-order fashion. Modifications of the crosslinker from the most commonly used tetraethylorthosilicate (TEOS) to the trifunctional 3-(2,3-epoxypropoxy)propyltrimethoxysilane (SIG) and a 1:1 mixture of the two were undertaken. Addition of methylpolysiloxane-copolymers were studied. Lactose, microcrystalline cellulose (MCC) and polyethylene glycol 8000 (PEG) were the channeling agents applied. The effects on dispersion properties were characterized by particle size distribution and viscosity. Mechanical properties of resulting free films were studied to determine applicability in a pan-coating process. Release of hydrochlorothiazide (marker drug) was studied from tablets coated in a lab-size conventional coating pan. All dispersions were found suitable for a spray-coating process. Preparation of free films showed that copolymer addition was not possible due to great decline in mechanical properties. Tablets coated with formulations containing PEG were most suitable to control drug release, at only 5% coating weight. Constant release rates could be achieved for formulations with up to 25% PEG; higher amounts resulted in a non-linear release pattern. Upon adding 50% PEG, a drug release of 63% over 24 h could be achieved.

Influence of methacrylic acid and hydroxypropylmethyl cellulose on the tablet properties and in vitro release of dextromethorphan hydrobromide

The release of dextromethorphan hydrobromide from matrices containing hydroxypropylmethyl cellulose (HPMC K100LV) and methacrylic acid copolymer (Eudragit L100-55) has been evaluated at different ratios of the polymers. The physicochemical properties (including weight, thickness, crushing strengh, friability and disintegration time) were also determined at 1000, 2000 and 4000 p compression forces. No significant differences in weight uniformity and thickness values were observed between the different formulations. The crushing strength of the tablets increased with increasing compression force and it reached a constant level at 4000 p. The formulations containing only HPMC K100LV resulted in an extended release pattern, however, Eudragit L100-55 alone could not effectively prolong the drug release. A combination of HPMC K100LV and Eudragit L100-55 in a 1:1 ratio at the 40% level provided an almost similar drug release profile than the marketed product.

Effect of drug proportion and mixing time on the content uniformity of a low dose drug in a high shear mixer

The purpose of this study was to investigate the effect of reducing drug proportion and mixing time on the content uniformity of a low dose drug. Buspirone hydrochloride was used as a model drug and was mixed with other ingredients in two different concentrations (0.5% w/w and 5% w/w) in a T. K. Fielder high shear mixer at a high impeller speed (522 rpm) and a high chopper speed (3600 rpm) up to 32 min. Samples were withdrawn from nine locations in the mixer at specific time points using a side-sampling thief probe. The final blends at 32 min were compressed using an instrumented tablet press. Tablets were sampled at the beginning, middle, and end of the compression run. The statistical results indicated that the drug proportion had a significant effect on the content uniformity of the powder blend and the corresponding tablets. For this study, the optimum time to mix the 0.5% w/w formulation was after 8 min while it was only 1 min for the 5% w/w formulation. The RSD of buspirone hydrochloride contents of tablets decreased as the compression run was toward its end. Uniformly mixed blends produced tablets that met the USP XXIV content uniformity requirements.

A comparative multidose pharmacokinetic study of buspirone extended-release tablets with a reference immediate-release product

Buspirone is disclosed in U.S. Patent No. 3,717,634 as a pharmaceutically active compound that has been found to be effective for the treatment of anxiety disorders and depression. In this randomized, two-treatment, two-period, multidose crossover study, the pharmacokinetics of a once-daily extended-release (ER)formulation of buspirone was compared with that of an immediate-release (IR) formulation of commercially available buspirone. A total of 30 mg of the ER formulation was administered to 36 healthy volunteers once daily for 7 days, and 15 mg of the IR formulation was administered twice daily for 7 days. Pharmacokinetic profiles of buspirone and its metabolite, 1-pyrimidinylpiperazine (1-PP), were obtained at steady state. The bioavailability of buspirone from the ER formulation was more than three times higher than that from the IR formulation at steady state, and that of 1-PP was about 25% less. The mean steady-state Cmax of buspirone from the ER formulation was 46% higher than that from the IR formulation (p < 0.05), and that for 1-PP was lower by 29% (p < 0.05). The mean apparent half-life of buspirone from the ER formulation (9.04 hours) was considerably longer than that observed for the IR formulation (3.06 hours). The median 1-PP/buspirone AUC ratio was much higher for the IR formulation at steady state (24.4) than for the ER formulation (6.44). There were no significant differences in average pharmacokinetic metrics observed in men and women. Based on these observations of the potential benefits of once-daily dosing with the ER product in terms of prolonged buspirone plasma concentrations, a significant increase in the ratio of buspirone to 1-PP concentration with a lower intersubject variation could be achieved that should provide an improvement in the desired therapeutic effects of buspirone.

Effect of anionic polymers on the release of propranolol hydrochloride from matrix tablets

Anionic polymers, namely Eudragit S, Eudragit L 100-55, and sodium carboxymethylcellulose, were incorporated into hydroxypropylmethylcellulose (HPMC K100M) to modify the drug release from HPMC matrices. The effects of changing the ratio of HPMC to anionic polymers were examined in water and in media with different pH. The dissolution profiles were compared according to release rates. The interaction between propranolol hydrochloride and anionic polymers was confirmed using the UV difference spectra method. The drug release was controlled with the type of anionic polymer and the interaction between propranolol hydrochloride and anionic polymers. The HPMC-anionic polymer ratio also influenced the drug release. The matrix containing HPMC-Eudragit L 100-55 (1:1 ratio) produced pH-independent extended-release tablets in water, 0.1 N HCl, and pH 6.8 phosphate buffer.

Pharmacokinetics of buspirone extended-release tablets: a single-dose study

The objective of this study is to evaluate the absorption of buspirone and its biotransformation to 1-(2-pyrimidinyl) piperazine (1-PP) from two different extended-release (ER) formulations of buspirone HCl tablets (12-hour and 24-hour in vitro release) and from a commercially available immediate-release (IR) tablet. A single dose of the 30 mg ER tablets was compared with two doses of the 15 mg IR tablet administered 12 hours apart. Eighteen healthy male subjects participated in this randomized, open-label, three-treatment crossover study. Blood samples were obtained at 22 time points from predose (0 hour) until 36 hours postdose, and plasma concentration of buspirone and 1-PP was determined by LC/tandem mass spectrometry method. The pharmacokinetic parameters AUC0-t, AUC0-infinity, Cmax, tmax, Ke, and t1/2 were calculated and statistically analyzed. The results indicated extended release of buspirone from the two test products in vivo with a 70% to 90% greater bioavailability in comparison with the IR formulation. The bioavailability of 1-PP from ER formulations appears to be equal to that from the IR formulation. Both buspirone ER tablets successfully delivered bioavailable buspirone with a reduction in peak drug and metabolite plasma levels, prolonged buspirone plasma concentrations, and decreased ratio of 1-PP to buspirone concentration with less intersubject variation when evaluated as a single-dose study in healthy human subjects.

The effects of packaging on the stability of a moisture sensitive compound

Packages that provided stability (less than a 10% loss in potency) of a moisture sensitive compound (PGE-7762928) in tablet form at accelerated conditions for 6 months were identified. The equilibrium moisture content of the tablets at 25 degrees C/60%RH, 30 degrees C/60%RH and 40 degrees C/75%RH were 2.3,2.4, and 2.9%, respectively. The tablet equilibrium moisture content, degradation rate of unpackaged product, and the moisture barrier properties of the packages were used to predict the stability of the packaged product. The physical and chemical stability (HPLC assay) of the products were measured after 2,4,6,8,12, and 24 weeks at ICH conditions. The Containers-Permeation(1) of polyvinyl chloride blisters, cyclic olefin blisters, aclar blisters, cold-form aluminum blisters was 0.259, 0.040, 0.008 and 0.001 mg per blister per day, respectively. At 6 months at 40 degrees C/75%RH, the percent active was 84% in polyvinyl chloride blisters, 91% in cyclic olefin blisters, 97% in aclar blisters, 100% in cold-form aluminum blisters and 99% in an high density polyethylene bottle with a foil induction seal. The stability results for the packaged product were fairly consistent with the predictions based on the moisture sensitivity of the product and the moisture barrier properties of the respective package. To gain a better prediction, the flux value determined by the Containers-Permeation procedure was adjusted for the internal moisture concentration of the blister.

Application of multiple response optimization technique to extended release formulations design

The purpose of the present study was to apply response surface methodology and multiple response optimization utilizing superimposed contour diagrams to design extended release formulations with a preplanned release profile. Bumetanide solution was layered on sugar pellets followed by coating with various coating formulations according to a central composite statistical design using a Glatt GPCG 1 Wurster Fluid Bed. The coated pellets were tested for their release profiles and the percent of drug released after 1, 4 and 8 h were used to describe and optimize the release process. Statistical models describing the percent bumetanide released after 1, 4 and 8 h were developed and the corresponding contour diagrams were superimposed to predict the coating formulation parameters expected to produce target release profile. The pellets coated with the designed coating formulation were tested for their release profiles in comparison to the target profile. According to the model-independent approach using similarity factor (F2), the dissolution profile of the designed formulation and the expected target profile were found to be similar. It was concluded that response surface methodology and multiple response optimization could be successfully used to design and optimize extended release formulations with desired preplanned release profile.

SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF NEW 4H-PYRANO [3,2-h]QUINOLINES AND FUSED DERIVATIVES

The starting materials, 2-amino-3-cyano-4-(3,4,5-trimethoxyphenyl)-4H-pyran0[3,2-hlquinoline 1 and ethyl-2-amino-4-(3,4,5-trimethoxyphenyl)-4H-pyrano [3,2-hlquinolin-3-carboxylate 2 were synthesised from 8-hydroxyquinoline and a-cyano-3,4,5-trimethoxycinnamonitrileand/or ethyl-a-cyano-3,4,5-trimethoxy-cinnamatre respectively. In order to construct a third heterocyclic ring 1 and 2were condensed with ethyl bromoacetate, formarnide, carbon disulfide to afford pyrrolo-, pyrimido- and thiazinopyranoquinolines 3-6respectively. The S-alkylated products 7 and 8 were obtained by the effect of chloroacetonitrile and/or ethyl chloroacetate on thiazinopyranoquinoline derivative 6. The attempt of cyanomethylation of the amino functional group of 1 to yield 10 with chloroacetonitrile in AcOHIAcONa failed and instead, pyridopyranoquinoline derivative 9 was obtained which is visualized to occur via cyclization of the initially formed acetylarnino derivative by nucleophilic attack on the cyano group. Acetylation of 1 and 2 with acetic anhydride afforded the mono- and di-acetyl derivatives 11a and 11b respectively. A plausible explanation to form the mono-derivative with 1 and the di-derivative with 2 is the higher deactivating effect of the cyano function over that of the carboxyethyl group. Furoylation of 1 and 2 was achieved by furoyl chloride to give 12a and 12b respectively. The structural features of pyranoquinoline 2 were inferred from its microanalysis and spectral data such as IR,1H-NMR and MS as well as its chemical reactions, as a bifunctional compound with carbon nucleophiles namely, phenyl isothiocyanate and nitrogen nucleophilic species namely, p-toluidine, benzylamine, aniline and hydrazine hydrate to give pyrimidopyranoquinoline derivative 13, carboxamides 14a-c and carboxyhydrazide 15 respectively. When the hydrazide 15 was treated with carbon disulfide inpresence of KOH, it afforded the potassium salt 16 which was submitted to react with hydrazine hydrate at room temperature to give 17. The hydrazido group of 15was utilized to construct heterocyclic moieties attached to postion-3 of the pyranoquinoline structure. Thus, the reaction of the carboxyhydrazide15 with phenyl isothiocyanate, acetylacetone, and benzoylacetone resulted in the formation of 18, 19a and 19b respectively. Ethyl carbazate as a typical mesophile reacted with 2 to afford a fused tetracyclic product triazepinopyranoquinoline 20 via cyclization of the initially formed hydrazide. Among sixteen compounds screened against E. coli and S. aureus respectively,compounds 2 and 14c show a high order of antibacterial activity against both bacteria. 12b is strongly potent against Staphylococcus aureus.

A severe genotype with favourable outcome in very long chain acyl-CoA dehydrogenase deficiency

A patient with very long chain acyl-CoA dehydrogenase (VLCAD) deficiency is reported. He had a severe neonatal presentation and cardiomyopathy. He was found to be homozygous for a severe mutation with no residual enzyme activity. Tandem mass spectrometry on dried blood spots revealed increased long chain acylcarnitines. VLCAD enzyme activity was severely decreased to 2% of control levels. Dietary management consisted of skimmed milk supplemented with medium chain triglycerides and L-carnitine. Outcome was good and there was no acute recurrence.

Predicting dissolution via hydrodynamics: salicylic acid tablets in flow through cell dissolution

A model was established for the dissolution of non-disintegrating salicylic acid tablets as a function of hydrodynamic conditions in the Flow Through Cell system (USP Apparatus 4). The approach was to model the dissolution rate of the material as a function of the Reynold's number, the dimensionless engineering term that describes the degree of turbulence. The dissolution rate of USP calibrator salicylic acid tablets was measured as a function of tablet size, orientation within the cell, dissolution media flow rate, and cell size. All of these variables were found to have an effect on dissolution rate, consistent with theory. An equation to predict this dissolution was established as: N(SH)=-21.1+12.6xN(RE)(0.5), R(2)=0.99; 10<N(re)<292.

Liquid chromatographic method for the analysis of buspirone HCl and its potential impurities

An accurate, reproducible, and sensitive method for the determination of buspirone HCl and its potential impurities is developed and validated. The validated liquid chromaography method is conducted to meet the Food and Drug Administration/ International Conference on Harmonization requirements for the analysis of buspirone HCI in the presence of its impurities. Five buspirone HCI potential impurities, including 1-(2-pyrimidinyl)-piperazine (I), propargyl chloride (II), 3,3'-tetramethylene glutarimide (III), propargyl glutarimide (IV), and the Mannich base-condensate of I-IV fumarate (V), are separated using a microBondapack C18 column by gradient elution with a flow rate 2.0 mL/min. The initial mobile phase composition is 90:10 (v/v) 10mM KH2PO4 (pH 6.1)-acetonitrile. After a 1-min initial hold, a linear gradient is performed in 26 min to 35:65 (v/v) 10mM KH2PO4 (pH 6.1)-acetonitrile. The samples are detected at 210 and 240 nm using a photo-diode array detector. The linear range of detection for buspirone HCI was between 1.25 ng/microL and 500 ng/microL, with a limit of quantification of 1.25 ng/microL. The linearity, range, peak purity, selectivity, system performance parameters, precision, accuracy, and robustness for all of the impurities were also shown to have acceptable values.

Stability-indicating high-performance liquid chromatographic assay of buspirone HCl

The United States Pharmacopoeia high-performance liquid chromatographic (HPLC) assay method of buspirone is not able to discriminate buspirone from its degradation products. The purpose of this work is to develop a sensitive, selective, and validated stability-indicating HPLC assay for the analysis of a buspirone hydrochloride in a bulk drug. Buspirone HCI and its potential impurities and degradation products are analyzed on an Ultrasphere C18 column heated to 40 degrees C using a gradient program that contains monobasic potassium phosphate buffer solution (pH 6.9) and acetonitrile-methanol mixture (13:17) of 35% for 5 minutes, then increased to 54% in 5.5 minutes. The samples are monitored using a photo-diode array detector and integrated at 244 and 210 nm. The stress testing of buspirone HCI shows that buspirone acid hydrochloride is the major degradation product. The developed method shows a separation of buspirone degradation product and its potential impurities in one run. The stability of buspirone HCI is studied under accelerated conditions in order to provide a rapid indication of differences that might result from a change in the manufacturing process or source of the sample. The forced degradation conditions include the effect of heat, moisture, light, acid-base hydrolysis, sonication, and oxidation. The compatibility of buspirone HCI with some pharmaceutical excipients is studied under stress conditions. The linear range of buspirone HCI is between 5 and 200 ng/microL with a limit of quantitation of 2.5 ng/microL. The intraassay percentage deviation is not more than 0.38%, and the day-to-day variation was not more than 0.80%. The selectivity, repeatability, linearity, range, accuracy, sample solution stability, ruggedness, and robustness show acceptable values.

Modeling of a roller-compaction process using neural networks and genetic algorithms

In this study, roller-compaction of acetaminophene was studied to model the effect of binder type (hydroxypropyl methyl cellulose (HPMC), polyethylene glycol (PEG), Carbopol), binder concentration (5, 10 and 20%), number of roller-compaction passes (one or two), and extragranular microcrystalline cellulose addition on the properties of compressed tablets. Forty-two batches resulted from the experimental design. The artificial neural network methodology (ANN) along with genetic algorithms were used for data analysis and optimization. ANN and genetic models provided R2 values between 0.3593 and 0.9991 for measured responses. When a set of validation experiments was analyzed, genetic algorithm predictions of tablet characteristics were much better than the ANN. Optimization based on genetic algorithm showed that using HPMC at 20%, with two roller-compaction passes would produce mechanically acceptable acetaminophene tablets. PEG and carbopol would also produce acceptable tablets perhaps more suitable for sustained release applications. Using PEG as a binder had the additional advantage of not requiring an external lubricant during tablet manufacturing.