[Research progress in stent associated respiratory tract infection]

Airway stents are commonly used to treat patients with central airway obstruction, but several complications have been identified, including mucus plugging, granulation tissue, stent migration, and infection. Stent associated respiratory tract infection (SARTI) has often been neglected by the practicing clinicians. Therefore, we reviewed the available current literatures on the diagnosis and management of stent associated respiratory tract infection.

[A survey on the practice of bronchoscopy in county-level hospitals of China]

Objective: To investigate the bronchoscopy resource allocation and technology application in county-level hospitals in China. Methods: A cross-sectional survey was conducted. In 2021, 12 provinces were sampled from all provinces in China according to the regional Gross Domestic Product (GDP) and the number of counties, in which a total of 291 county-level hospitals were randomly enrolled. Two county-level hospitals which carried out bronchoscopy technology in each province were randomly sampled to investigate the status of bronchoscopy resources, technical application, decontamination and anesthesia by using questionnaires. Independent sample t test or two related sample nonparametric test were used for comparison between groups. Spearman correlation analysis was used to explore the correlation. Bilateral P<0.05 was considered statistically significant. Results: According to the sampling results, it was estimated that in the county-level hospitals, the proportion of those performing bronchoscopy was 11.4% (9.9%, 13.8%), which was significantly correlated with the population in the province (r=0.64, P=0.025) and the regional GDP (r=0.65, P=0.025).The 24 county-level hospitals interviewed were equipped with (1.6±1.0) bronchoscopes on average, and the number of hospitals with electronic bronchoscopes and fiberoptic bronchoscopes was 22 (91.7%) and 6 (25.0%), respectively. Six (25.0%) hospitals performed bronchoscopy every working day. Twelve (50.0%) hospitals had relatively permanent physicians and nurses. All operating doctors had received special training. There was a significant increase in the number of bronchoscopy cases per hospital in 2020 compared to 2019 [140(70, 335) vs. 100(29, 254), P=0.001]. All hospitals used standard cleaning and sterilization workbenches, cleaning agents and disinfectants. Surface anesthesia was available in 24 hospitals, and bronchoscopy techniques under sedation and analgesia were performed in 10 (41.7%) hospitals. Atropine was still used to prevent airway secretions in 2 (8.3%) hospitals,although not recommended by guidelines. Conclusions: There was a large gap between the current status of bronchoscopy technology in county-level hospitals and the standards of the National Health Commission, together with regional disparities. Bronchoscopist training in the standardization and the decontamination work met the requirements. In some hospitals, the use of complementary medicines was not standardized or the sedatives were not given routinely according to the guidelines. We should promote the popularization and standardization of bronchoscopy technology, and strengthen the allocation of related resources in China's county hospitals.

A Case of Emphysematous Cystitis

Emphysematous cystitis (EC) is an uncommon but potentially life-threatening urinary tract infection. Diagnostic difficulty exists because of the variable presentations. We report the case of a 73-year-old woman who presented with diarrhoea and malaise, and emphysematous cystitis was revealed on the abdominal X-ray. As she was treated for EC, the diarrhoea and the radiographic abnormalities of EC also resolved. The evaluation and management of this complicated urinary tract infection are discussed.

[Effect of nicotinic acetylcholine receptor α7 subunit gene on liver inflammatory reaction in mice with nonalcoholic steatohepatitis and related mechanisms]

Objective: To investigate the effect of nicotinic acetylcholine receptor α7 (α7nAChR) subunit gene on liver inflammation in mice with nonalcoholic steatohepatitis (NASH) and related mechanisms. Methods: C57BL/6J mice and α7nAChR gene knockout mice were fed for 24 weeks to establish the NASH model, and the mice were sacrificed to isolate and culture the primary liver macrophages. After the treatment with nicotine and endotoxin, ELISA was used to measure the levels of the inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in supernatant; indirect immunofluorescence assay and Western blot were used to observe the effect on the NF-κB signaling pathway, and quantitative PCR was used to measure the mRNA expression of Toll-like receptor-4 (TLR-4) in macrophages. An analysis of variance was used for comparison of means between multiple groups. Results: The results of ELISA showed that compared with the endotoxin+nicotine group of C57 NASH mice, the endotoxin+nicotine group of gene knockout NASH mice had significantly higher levels of IL-6 and TNF-α in supernatant (IL-6: 1 599±65 pg/ml vs 1 465±45 pg/ml, P < 0.05; TNF-α: 1 567±66 pg/ml vs 1 433±50 pg/ml, P < 0.05). The results of Western blot showed that compared with the endotoxin+nicotine group of C57 NASH mice, the endotoxin+nicotine group of gene knockout NASH mice had significantly higher relative protein expression of phosphorylated NF-κB and TLR-4 (NF-κB: 69 425±600 vs 51 133±200, P < 0.05; TLR-4: 93 387±684 vs 64 198±630, P < 0.05). The results of indirect immunofluorescence assay showed that the endotoxin+nicotine group of gene knockout NASH mice had a significantly higher fluorescence intensity of NF-κB than the endotoxin+nicotine group of C57 NASH mice. The results of PCR showed that the endotoxin+nicotine group of gene knockout NASH mice had significantly higher relative mRNA expression of TLR-4 than the endotoxin+nicotine group of C57 NASH mice (4.13±0.13 vs 2.93±0.14, P < 0.05). Conclusion: The α7nAChR gene knockout can aggravate the degree of inflammatory reaction in NASH, and its mechanism may be related to the fact that the NF-κB signaling pathway cannot be inhibited, which aggravates inflammatory reaction.

[Features and advances of Morse taper connection in oral implant]

Dental implants have been widely accepted as a predictable and reliable tool for dental reconstruction with the development of the economy. The design of implant-abutment connections has influence on mechanical properties and biological characteristics of implants. There are two types of implant-abutment connections, the external and the internal connections. Morse taper connection is one of the internal connections and its conical shape creates significant friction via the high propensity of parallelism between the two structures within the joint space. Several studies showed that Morse taper connection performed well in terms of survival rate, stability, bacterial seal and marginal bone loss. Recently, clinical studies indicate implants combining Morse taper connection with platform switching are helpful in reducing marginal bone absorption. This review aims at analyzing the features and advantages of Morse taper connection.

Efficient biosynthesis of d-ribose using a novel co-feeding strategy in Bacillus subtilis without acid formation

Normally, low d-ribose production was identified as responsible for plenty of acid formation by Bacillus subtilis due to its carbon overflow. An approach of co-feeding glucose and sodium citrate is developed here and had been proved to be useful in d-ribose production. This strategy is critical because it affects the cell concentration, the productivity of d-ribose and, especially, the formation of by-products such as acetoin, lactate and acetate. d-ribose production was increased by 59·6% from 71·06 to 113·41 g l^-1 without acid formation by co-feeding 2·22 g l^-1  h^-1 glucose and 0·036 g l^-1  h^-1 sodium citrate to a 60 g l^-1 glucose reaction system. Actually, the cell density was also enhanced from 11·51 to 13·84 g l^-1 . These parameters revealed the importance of optimization and modelling of the d-ribose production process. Not only could zero acid formation was achieved over a wide range of co-feeding rate by reducing glycolytic flux drastically but also the cell density and d-ribose yield were elevated by increasing the hexose monophosphate pathway flux.

SIGNIFICANCE AND IMPACT OF THE STUDY

Bacillus subtilis usually produce d-ribose accompanied by plenty of organic acids when glucose is used as a carbon source, which is considered to be a consequence of mismatched glycolytic and tricarboxylic acid cycle capacities. This is the first study to provide high-efficiency biosynthesis of d-ribose without organic acid formation in B. subtilis, which would be lower than the cost of separation and purification. The strain transketolase-deficient B. subtilis CGMCC 3720 can be potentially applied to the production of d-ribose in industry.

Factors Affecting the Enhancement Patterns of Intrahepatic Cholangiocarcinoma (ICC) on Contrast-Enhanced Ultrasound (CEUS) and their Pathological Correlations in Patients with a Single Lesion

Purpose: To investigate the factors that influence the enhancement patterns of intrahepatic cholangiocarcinomas (ICC) on contrast-enhanced ultrasound (CEUS) and analyze the correlations between the enhancement patterns on CEUS and pathological findings. Materials and Methods: Ninety-six patients with 96 pathologically confirmed ICCs underwent CEUS. CEUS images were retrospectively evaluated for tumor enhancement patterns in the arterial, portal and late phases. The arterial enhancement patterns were correlated with clinicopathological factors. The possible influencing factors were correlated with pathologic findings. Results: Thirty-six patients with ICC demonstrated rim-like enhancement, and 60 exhibited non-rim-like enhancement in the arterial phase on CEUS. The incidence of non-rim-like-enhancing ICCs was higher in patients with cirrhosis and chronic viral hepatitis than patients with no chronic liver disease (p = 0.001). The sizes of the ICCs with homogeneous hyper-enhancement were significantly smaller than those with inhomogeneous hyper-enhancement (p = 0.007). Arterial non-rim-like-enhancing ICCs showed higher microvessel density (MVD) and arterial density (AD) and less fibrous stroma and necrosis than rim-like-enhancing ICCs. Arterial inhomogeneous-enhancing ICCs had lower MVD and AD and much more fibrous stroma and necrosis than homogeneous-enhancing ICCs. Conclusion: The enhancement pattern of ICCs in the arterial phase on CEUS was affected by a liver cirrhosis and chronic viral hepatitis and tumor size. The amount of MVD, AD, fibrous stroma and necrosis in ICC tumors may be responsible for the difference in the enhancement patterns.

[Nicotine alleviates the liver inflammation of non-alcoholic steatohepatitis induced by high-fat and high-fructose in mice]

OBJECTIVE

To investigate the anti-inflammation effects by activation of the cholinergic anti-inflammatory pathway and its mechanisms in non-alcoholic steatohepatitis (NASH) model mice.

METHODS

6-week-old male C57BL/6J (B6) mice were randomly divided into four groups: the first group was normal mice, injected with saline; the second group was normal mice, injected with nicotine; the third group was NASH model mice, injected with saline; the fourth group was NASH model mice, injected with nicotine. The experimental mice were fed with either standard chow (SC) or high-fat and high-fructose (HFHF) for 17 weeks to generate an NASH model mice. The mice received injection once daily for 3 weeks [nicotine dose, 400 μg/kg]. Then, their pathological characteristics and function of the liver were assessed. The expressions of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in serum were analyzed by enzyme linked immunosorbent assay (ELISA). The expressions of alpha 7 nicotinic acetylcholine receptors (α7nAChR), Toll-like receptors-4 (TLR-4) and nuclear factor κB of phosphory-lation (p-NF-κB) in Kupffer cells were determined by Western blot and immunofluorescence assays.

RESULTS

We successfully generated NASH model mice by imitating the high-fat and high-fructose dietary style of NASH patients. The results of our investigation demonstrated that nicotine could reduce significantly the levels of IL-6, and TNF-α in serum (P<0.05). The expression of p-NF-κB protein in the group which was NASH model mice injected with nicotine declined significantly as compared with the group which was NASH model mice injected with saline (P<0.05). And the expression of α7nAChR protein elevated significantly conversely (P<0.05).

CONCLUSION

Activation of the cholinergic anti-inflammatory pathway could inhibit the release of inflammatory factors as TNF-α and IL-6 in NASH model mice, and the mechanism for the inhibition of inflammatory was mediated by NF-κB pathway.

Palliative surgical intervention in metastatic colorectal carcinoma: a prospective analysis of quality of life

AIM

Quality of life (QOL) was assessed after palliative surgery for incurable metastatic colorectal cancer (CRC).

METHOD

Newly diagnosed patients with incurable metastatic CRC who were offered elective palliative surgical intervention were included. The European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-CR29 questionnaire was used for the assessment of QOL at baseline and at 3 and 6 months after surgery. Generalized estimating equations were used to estimate the mean change in the QOL score from baseline.

RESULTS

Twenty-four patients formed the study group. Sixteen underwent resection of the primary tumour and eight had a proximal diversion or bypass. The Global Health (GH) score and Social Functioning (SF) score improved at 3 and 6 months after intervention respectively (GH +11, P = 0.021; SF +15, P = 0.005). Mean anxiety scores were markedly improved from the baseline of 51 to 71 (P = 0.004, 3 months) and 76 (P = 0.002, 6 months). Weight concerns also improved significantly when compared with baseline (3 months, +20, P < 0.001; 6 months, +14, P = 0.012). Symptoms of diarrhoea (3 months, --17, P = 0.007; 6 months,--16, P = 0.008) and nausea (--8, P = 0.032) improved.

CONCLUSION

In patients with incurable metastatic CRC, surgery improved QOL.

A scoring model for predicting survival following primary tumour resection in stage IV colorectal cancer patients with unresectable metastasis

BACKGROUND

Stage IV colorectal cancer patients with unresectable metastasis who undergo elective primary tumour resection experience heterogeneous post-operative survival. We aimed to develop a scoring model for predicting post-operative survival using pre-operative variables to identify patients who are least likely to experience extended survival following the procedure.

METHODS

Survival data were collected from stage IV colorectal cancer patients who had undergone elective primary tumour resection between January 1999 and December 2007. Coefficients of significant covariates from the multivariate Cox regression model were used to compute individual survival scores to classify patients into three prognostic groups. A survival function was derived for each group via Kaplan-Meier estimation. Internal validation was performed.

RESULTS

Advanced age (hazard ratio, HR 1.43 (1.16-1.78)); poorly differentiated tumour (HR 2.72 (1.49-5.04)); metastasis to liver (HR 1.76 (1.33-2.33)), lung (HR 1.37 (1.10-1.71)) and bone (HR 2.08 ((1.16-3.71)); carcinomatosis (HR 1.68 (1.30-2.16)); hypoalbuminaemia (HR 1.30 (1.04-1.61) and elevated carcinoembryonic antigen levels (HR 1.89 (1.49-2.39)) significantly shorten post-operative survival. The scoring model separated patients into three prognostic groups with distinct median survival lengths of 4.8, 12.4 and 18.6 months (p < 0.0001). Internal validation revealed a concordance probability estimate of 0.65 and a time-dependent area under receiver operating curve of 0.75 at 6 months. Temporal split-sample validation implied good local generalizability to future patient populations (p < 0.0001).

CONCLUSION

Predicting survival following elective primary tumour resection using pre-operative variables has been demonstrated with the scoring model developed. Model-based survival prognostication can support clinical decisions on elective primary tumour resection eligibility.

Tracheotomy: an alternative for tracheobronchial foreign body removal

A 6 years old girl accidentally aspirated a plastic whistle while playing. Computed Tomography of thorax showed foreign body at carina level. Rigid bronchoscope under general anesthesia was attempted but unable to extract the whistle through vocal cord. Tracheostomy was later performed and foreign body was removed.

Successful resuscitation after out-of-hospital cardiac arrest

A 66-year-old woman presented to the emergency department after a witnessed cardiac arrest, having had compression-only cardiopulmonary resuscitation initiated by her son on the backseat of his car. She was resuscitated in the emergency department for 1 hour before the return of spontaneous circulation. She then underwent primary percutaneous coronary intervention and therapeutic hypothermia. She was discharged without significant neurological deficit. This case illustrates better survival and neurological outcome can be achieved by prompt implementation of a 'chain of survival' interventions and therapeutic hypothermia.

Reversal of Hartmann's procedure: experience in an Asian population

INTRODUCTION

With improvements in surgical techniques, instrumentation and perioperative care, Hartmann's procedure is now less frequently performed. Restoration of intestinal continuity after Hartmann's procedure has traditionally been viewed to be technically demanding and associated with significant morbidity and mortality. This is a study of outcomes after the reversal of Hartmann's procedure in an Asian population.

METHODS

A prospectively collected database showed that 255 patients had undergone Hartmann's procedure from October 1989 to October 2005. Patients who subsequently underwent Hartmann's reversal were identified and their records reviewed retrospectively.

RESULTS

Hartmann's reversal was attempted in 49 patients. The most common indication for Hartmann's procedure was colorectal carcinoma (49.0%). The median interval between resection and reversal was 23 weeks. Reversal was successful in 46 (93.9%) patients, with 79.6% experiencing no intraoperative complications. Failure of reversal was significantly associated with prior radiotherapy to the pelvis (p-value = 0.007). Anastomotic leak rates and re-bleeding rates were both 0.0%. 79.6% of patients made an uneventful recovery with no postoperative complications. There was no significant increase in the complication rate in older patients or patients with higher American Society of Anesthesiologists status. The overall incidence of 30-day morbidity and mortality was 20.4% and 0.0%, respectively.

CONCLUSION

In our population, Hartmann's procedure is more commonly performed for colorectal cancer rather than for diverticular disease, resulting in lower rates of stoma reversal. Hartmann's reversal could be performed with acceptable morbidity and minimal mortality, although prior radiotherapy and shorter rectal stump may pose challenges during reversal surgery.

Twenty years of familial adenomatosis polyposis syndromes in the Singapore Polyposis Registry: an analysis of outcomes

INTRODUCTION

The Singapore Polyposis Registry (SPR) was established in 1989 at the Singapore General Hospital. This initiative was aimed at providing a central registry service to facilitate identification, surveillance and management of families and individuals at high risk of colorectal cancer. The aim of the present study was to provide a comprehensive review of all patients with familial adenomatous polyposis (FAP) syndrome in the SPR.

METHODS

All patients diagnosed with FAP in 1989-2009 were analysed. Data was extracted from a prospectively collected database.

RESULTS

122 patients from 88 families were analysed. The median age of this cohort was 29 (range 10-68) years. 97 percent of the cases were FAP and 3 percent were attenuated FAP. 92 patients tested positive for adenomatous polyposis coli gene. 42 percent of patients were diagnosed with colorectal cancer, of which 78 percent were diagnosed at an advanced stage. 73 percent of patients underwent restorative proctocolectomy and 21 percent had total colectomy. The median age at operation was 30 years. At median follow-up of 98 months, ten-year overall survival was 75.6 percent (95 percent confidence interval 67.0-84.2) and the median age at death was 40 years. For cancer cases, the overall recurrence was 13.5 percent. Recurrence and disease-free survival were not significant for the type of surgery performed (p-value is 0.486).

CONCLUSION

The SPR plays an important and integral part in counselling patients and families with FAP. Improved surveillance programmes may be required to detect the development of cancers in these patients at an earlier stage.

418 cases of laparoscopic colorectal resections: a single-institution experience and literature review

INTRODUCTION

Evidence from randomised controlled trials has shown that laparoscopic colon and rectal cancer resection not only confers short-term benefits but also does not differ considerably in terms of its long-term oncological outcomes, as compared with open surgery.

METHODS

All laparoscopic colon and rectal resections performed between January 2005 and December 2007 were included. Patient records were reviewed from a prospective database and the relevant clinical data was obtained, with a subgroup analysis of cancer procedures performed.

RESULTS

418 patients (247 male), median age 63 years (range 24 to 88), underwent laparoscopic resection of the colon and rectum. The median Body Mass Index (BMI) was 22.5 (range 13.5 to 39.3). The majority of the procedures were performed for malignant disease (81.3 percent) and the most common procedure was anterior resection (79.4 percent). The median duration of surgery was 135 minutes (range 65 to 330), with conversions to open surgery in 44 patients (10.5 percent). Complications occurred in 78 patients (18.7 percent), including anastomotic leaks in five (1.20 percent). The median length of hospital stay was five days (range 3 to 90) and the median follow-up was 19 months (range 1 to 46). In the 340 patients with malignant disease, the median number of lymph nodes harvested was 13 (range 5 to 48), and at the latest review, 230 patients (67.6 percent) were disease-free, with locoregional recurrence in 2.9 percent and systemic recurrence in 10 percent.

CONCLUSION

To date, this is the largest series of laparoscopic colorectal resections reported locally, and our results show that it is safe, feasible and produces favourable results.

Radiation proctitis: a decade's experience

INTRODUCTION

Pelvic radiotherapy is an essential component of potentially curative therapy for many pelvic malignancies; however, the rectum consequently often sustains collateral injury.

METHODS

The researchers retrieved patient data that was prospectively gathered over a ten-year period between January 1995 and December 2004. The relevant details, including gender, age, pelvic pathology for which radiotherapy was administered, the presenting symptoms, the interval between radiotherapy and the onset of symptoms, the mode of diagnosis, treatments received, length of hospital stay and duration of follow-up, were analysed.

RESULTS

During the period under review, 77 patients were admitted for the treatment of radiation proctitis, with a median follow-up period of 14 (range 1-61) months. There were 23 male and 54 female patients, with a median age of 63.9 (range 37-89) years. The most common underlying cancers were gynaecological (63.6 percent), prostate (18.2 percent) and colorectal (15.6 percent) cancer. The most common presenting symptom was bleeding per rectum (89.6 percent), with a change in bowel habits a distant second (10.4 percent). The median latent period between the completion of radiotherapy and the onset of symptoms was 24 (range 3-68) months. The majority of the patients (72.5 percent) received non-surgical treatment, most commonly using topical 4 percent formalin solution to arrest the bleeding, with more than half the patients requiring repeat treatments. 14 (18.2 percent) patients required colorectal resections for intractable bleeding, intestinal obstruction or intra-abdominal sepsis.

CONCLUSION

Radiation proctitis can be a therapeutic challenge, even in the most experienced hands. The majority of patients who present with per rectal bleeding can be treated using topical modalities, while surgery may offer the only chance of relief from life-threatening symptoms.

Meta-analysis of defunctioning stomas in low anterior resection for rectal cancer

BACKGROUND

A defunctioning stoma is frequently created to minimize the impact of any subsequent anastomotic leak after a low rectal anastomosis. This review evaluates the need for routine stoma formation.

METHODS

A meta-analysis was performed of randomized controlled trials (RCTs) and non-randomized studies with an interventional group evaluating the need for a defunctioning stoma after low anterior resection for rectal cancer. Primary outcomes analysed included clinical anastomotic leak rate, reoperation rate and mortality related to leak.

RESULTS

Four RCTs and 21 non-randomized studies, with 11,429 patients in total, were analysed. Meta-analysis of the RCTs showed a lower clinical anastomotic leak rate (risk ratio (RR) 0.39 (95 per cent c.i. 0.23 to 0.66); P < 0.001) and a lower reoperation rate (RR 0.29 (0.16 to 0.53); P < 0.001) in the stoma group. Meta-analysis of the non-randomized studies showed a lower clinical anastomotic leak rate (RR 0.74 (0.67 to 0.83); P < 0.001), lower reoperation rate (RR 0.28 (0.23 to 0.35); P < 0.001) and lower mortality rate (RR 0.42 (0.28 to 0.61); P < 0.001) in the stoma group.

CONCLUSION

A defunctioning stoma decreases clinical anastomotic leak rate and reoperation rate. It is recommended after low anterior resection for rectal cancer.

Colorectal cancer mass screening event utilising quantitative faecal occult blood test

INTRODUCTION

Colorectal cancer (CRC) is a leading cause of morbidity and mortality with human and financial costs. Screening by faecal occult blood test (FOBT) has proven to be effective in decreasing mortality from CRC in both randomised trials and case-control studies. We report on the results of a CRC screening event using quantitative FOBT (QFOBT) held in Singapore.

METHODS

The mass screening event was held over two days, and participants 40 years or older without prior screening performed in the preceding year were eligible. Those with significant symptoms or medical comorbidities were excluded. Stool sampling was done with two issued immunochemical QFOBT kits, and participants with positive stool samples with equal or greater than 100 ng haemoglobin/ml sample solution in any two samples were advised to have a colonoscopy screening conducted.

RESULTS

A total of 1,048 participants took part in the screening event. 222 (21 percent) of the participants claimed to have some abdominal symptoms prior to screening. 49 participants (26 males, 23 females) tested positive for QFOBT and 47 were evaluated. 10 (21 percent) had polyps and one case of colorectal cancer was detected. Seven of these cases had significant neoplasia (lesions 1 cm or larger) and were treated. Two patients required surgery.

CONCLUSION

Our study demonstrates wide variation in the attitudes of participants who turned up for screening. In addition, the number of significant colorectal neoplasia patients (14 percent) in those with positive QFOBT provides further evidence of the importance of screening with a potential reduction in CRC mortality. Continuous education of the public in events such as this, is essential to improving attitudes towards screening.

Two Cases of Chickenpox Complicating Pregnancy and an Update on Management

Susceptible pregnant women with chickenpox exposure are uncommon but are medical emergency conditions. Chickenpox infection in the first trimester is associated with the congenital varicella syndrome and in the third trimester is associated with fatal complications and the neonatal varicella syndrome. In this article, two cases and the management of chickenpox during pregnancy are discussed.

A 6-year review of surgical morbidity and oncological outcome after high anterior resection for colorectal malignancy with and without splenic flexure mobilization

OBJECTIVE

High anterior resection (HAR) for colorectal cancer is traditionally performed with routine mobilization of the splenic flexure. This is a retrospective review of mortality and morbidity following HAR in which the splenic flexure has been preserved.

METHOD

From a prospective database, all patients who had undergone elective HAR for colorectal cancer between 1999 and 2005 were identified. Morbidity, mortality, pathology and survival data for patients having HAR with and without splenic flexure mobilization were analysed.

RESULTS

A total of 707 patients were identified. Five hundred and thirty-one had HAR with preservation of the splenic flexure. In these patients outcome was: anastomotic leak (0.4%), wound infection (3.6%), anastomotic stricture (0.4%) and 30-day mortality (0.9%). No statistical significant difference was found for postoperative morbidity (P = 0.1926), 30-day mortality (P =0.3285), lymph node harvest (P = 0.2127) or survival (P = 0.1457) compared with patients in whom the splenic flexure was mobilized. Longitudinal resection margins were greater following HAR with splenic flexure mobilization (P < 0.0001).

CONCLUSION

No morbidity, oncological or survival disadvantage in performing splenic flexure preserving HAR was found.

Meta-analysis of randomized clinical trials comparing drainage alone vs primary sphincter-cutting procedures for anorectal abscess-fistula

BACKGROUND AND AIM

Concurrent definitive treatment of underlying fistulas from infected anal glands at the time when the anorectal abscesses are drained is controversial as this is associated with a higher incidence of faecal incontinence, failure and recurrence. This meta-analysis was conducted to determine the merits of drainage alone vs primary sphincter-cutting procedures (which includes fistulotomy and fistulectomy) for anorectal abscess-fistula.

METHODS

Medline, Embase and Cochrane Central Register of Controlled Trials database searches identified all randomized controlled trials using the keywords: anorectal abscess, anal sepsis, drainage, fistulotomy, fistulectomy or surgery from 1966 to 2004. The outcome variables analysed were recurrence, faecal continence and wound-healing times.

RESULTS

Five trials were considered suitable for the meta-analysis, with a total of 405 patients. Sphincter-cutting procedures for anorectal abscesses resulted in 83% reduction in recurrence rate [relative risk (RR) 0.17, 95% confidence interval (CI) 0.09-0.32, p<0.001]. However, there was a tendency to a higher risk of faecal incontinence to flatus and soiling when primary sphincter-cutting procedure was performed (RR 2.46, 95% CI 0.75-8.06, p=0.140).

CONCLUSION

There is no conclusive evidence if simple drainage or sphincter-cutting procedure is better in the treatment of anorectal abscess-fistula.

PPH03 stapled hemorrhoidopexy: our experience

BACKGROUND

Stapled hemorrhoidopexy is an established treatment for hemorrhoidal disease. We evaluated our experience with stapled hemorrhoidopexy using the new Procedure for Prolapse and Hemorrhoids (PPH03) Proximate HCS hemorrhoidal circular stapler (Ethicon Endo-Surgery).

METHODS

We retrospectively reviewed clinical data for 238 patients who had undergone stapled hemorrhoidopexy in our department over a 2-month period. Patients were followed-up for a median of 3.5 weeks (range, 1-11 weeks) and were analyzed for complications and resolution of symptoms.

RESULTS

The hemorrhoids treated were third- and fourth-degree, as well as second degree (after failure of other therapies). Mean duration of surgery was 12.7 minutes (range, 5-20 minutes) and the majority of patients was treated with an ambulatory procedure. Most patients were discharged within 6 hours after surgery. On follow-up, 3.7% of patients had minor complaints after surgery. Technically, the new PPH03 stapler device has a quickclose knob, which allows rapid opening and closing. The closed staple height of 0.75 mm increases staple line compression on tissue and key blood vessels, hence minimizing bleeding. Prior to this, stapled hemorrhoidopexy was done using the PPH01 device.

CONCLUSIONS

Stapled hemorrhoidopexy using the new PPH03 stapler is a safe, short and effective procedure in the management of hemorrhoids. It can be done in the ambulatory setting and patients have few postoperative complications.

False positive F-18 fluorodeoxyglucose combined PET/CT scans from suture granuloma and chronic inflammation: report of two cases and review of literature

INTRODUCTION

F-18 fluorodeoxyglucose (FDG) combined positron emission tomography (PET)/ computed tomography (CT) imaging is often used in the surveillance of recurrent colorectal cancers after curative resections. We report 2 patients where FDG combined PET/CT imaging produced false positive results due to chronic inflammation and suture granuloma.

CLINICAL PICTURE

Case 1 is a patient with a curative anterior resection done 10 months ago. Serial surveillance carcinoembryonic antigen (CEA) showed a marginal elevation. A solitary "hot spot" on combined PET/CT imaging was seen at the level of the previously resected inferior mesenteric vein. Case 2 is a patient with a positive solitary lesion on combined PET/CT imaging 16 months after a curative right hemicolectomy for colorectal cancer. The serum CEA was within normal limits.

TREATMENT

Both patients had undergone exploratory laparotomy with complete resection of the solitary lesions.

OUTCOME

The histology of Case 1 was reported as a suture granuloma while the histology of Case 2 was reported as an inflammatory nodule related to the previous suture pedicle, both with no malignant tissues identified.

CONCLUSIONS

False positives on combined PET/CT imaging may result from inflammatory granulomas months after surgery.

High-sensitivity and specificity of laser-induced autofluorescence spectra for detection of colorectal cancer with an artificial neural network

An artificial neural network (ANN) has been used in various clinical research for the prediction and classification of data in cancer disease. Previous research in this direction focused on the correlation between various input parameters such as age, antigen, and size of tumor growth. Recently, laser-induced autofluorescence (LIAF) techniques have been shown to be a useful noninvasive early diagnostic tool for various cancer diseases. We report on a successful application of ANN to in vitro LIAF spectra. We show that classification of tumor samples with ANN can be done with high sensitivity, specificity, and accuracy. Thus a combination of LIAF techniques and ANN can provide a robust method for clinical diagnosis.

Which colorectal cancers are missed by double contrast barium enema?

BACKGROUND

The relative merits of either barium enema or colonoscopy for investigating lower gastrointestinal tract symptoms is still unclear. We studied the value of double contrast barium enema (DCBE) as the initial evaluation modality. We reviewed our 10-year experience of double contrast enemas as read by consultant radiologists. The study also aimed to identify which lesions are usually missed.

PATIENTS AND METHODS

We reviewed clinical data for all patients who underwent DCBE within the 6 months prior to surgical resection of colorectal cancer between April 1989 and April 1999. Patient demographics and tumour characteristics were analysed for their effects on the likelihood of the lesions being missed at DCBE.

RESULTS

There were 706 patients included in the study, 54.2% were male and the mean age was 63.7 years (SEM=0.5 years). The site along the colon and rectum of tumours missed by DCBE corresponded with the frequency of tumour occurrence at each site. The overall rate of missed lesions was 4.1% (29 of 706 patients); these patients were found on subsequent endoscopy to harbour cancer. Tumours less than 3 cm in length and with lesser extent of circumferential involvement were more likely missed at DCBE (p=0.05 and p=0.01, respectively). Age, sex, and tumour grade and stage were not significant predictors of the likelihood of missed lesions. Of the 29 patients with missed lesions, 77.2% had a serum concentration of carcinoembryonic antigen (CEA) above the normal range (3.5 microg/l). The mean follow-up was 65.3 months (SEM=1.8 months). The overall survival for this series was 60.1%. The inaccuracy of the initial DCBE was not found to cause statistically significant differences in the stage of the tumour at diagnosis nor the overall survival of the patients in our series.

CONCLUSIONS

Smaller cancers without circumferential involvement may be missed when DCBE is performed to evaluate lower gastrointestinal symptoms. Further evaluation by colonoscopy must be recommended when symptoms persist, especially in the context of a raised CEA level.

Minilaparotomy left iliac fossa skin crease incision vs. midline incision for left-sided colorectal cancer

BACKGROUND

Midline laparotomies offer excellent exposure but are associated with increased postoperative pain and longer recovery. A minilaparotomy resection of leftsided colorectal cancers was studied as an alternative approach.

PATIENTS AND METHODS

We performed a case-control retrospective review of 280 randomly selected patients (140 midline incisions; 140 left skin crease incisions) who underwent elective, curative resection of left-sided colorectal cancers.

RESULTS

Patients in both groups were of comparable age and sex. The left skin crease incision was shorter (median length, 13.5 cm) than the midline incision (median length, 20.0 cm). Median operation time was less in the left skin crease group (75 min) than in the midline incision group (105 min). Similar types of operations were performed, including left hemicolectomies, sigmoid colectomies, anterior resections and ultra-low anterior resections. Adequacy of resection was confirmed by histological analysis, with no involvement of margins. The median numbers of lymph nodes removed were comparable: 10 for the skin crease incision group and 12 for the midline incision group. Postoperative parameters for the skin crease incision group showed that feeding, ambulation, narcotic use and hospital stay were significantly better than the parameters in the midline group. Complications of intestinal obstruction were also reduced in the skin crease incision group.

CONCLUSIONS

The limited left skin crease incision provides adequate margins of clearance in colorectal cancers when compared to the midline incision, but has advantages of shorter operation time, earlier feeding and ambulation, and earlier discharge from hospital.

Distance and angular dependence of intensity ratios in laser-induced autofluorescence techniques

Laser-induced autofluorescence techniques have the potential to be used for the detection of preinvasive human cancer cells. For colorectal and gastrointestinal cancer cells, the light is introduced in vivo through endoscopic means and the probe tip is brought gently into contact with the tissue under investigation. However, it is often assumed that there is no distance or angular dependence in the intensity of the light collected from the probes. We performed an in vitro experiment in which we showed that there was indeed no angular dependence provided the angle of inclination of the probe to normal incidence is small. However, we find substantial fluctuation in the intensities of peaks for changing distances. These fluctuations can be eliminated by considering the ratio of the intensities from two spectral lines.

Chemoprevention of colorectal cancer--experimental approach and clinical applications

INTRODUCTION

The holy grail of cancer treatment is prevention. Chemoprevention is the use of specific agents to prevent, inhibit or reverse the process of cancer formation before malignancy. This review aims to explore the clinical approaches to investigation for chemoprevention and to discuss the more promising agents that have proceeded on to clinical trials.

METHODS

A Medline search was done using the words colorectal cancer, chemoprevention, models, surrogate markers and prevention clinical trials.

RESULTS

Research into chemopreventive agents is highly dependent on an effective model in which studies may be performed and from which results may be extrapolated into the human or clinical setting. As carcinogenesis is a prolonged biological event, intermediate surrogate markers that will reliably predict future cancer risk are usually studied. Various models are used with varying impact. Among some of the more recent agents being explored, the COX-2 inhibitors are emerging as strong potential agents. However, there are significant side-effects that need to be overcome first before routine use may be considered.

CONCLUSIONS

Although there is presently no agent available for the safe, widespread use for the chemoprevention of colorectal cancer, research into this area is rapidly progressing and may in the future change the paradigm of cancer treatment.

Prospective randomized study of bacteraemia in diathermy and stapled haemorrhoidectomy

BACKGROUND

The incidence and consequences of bacteraemia associated with diathermy and stapled haemorrhoidectomy have not been studied previously.

METHODS

Two hundred and five healthy patients randomized to stapled haemorrhoidectomy or diathermy haemorrhoidectomy had perioperative blood cultures taken. The clinical sequelae of bacteraemia and complications of surgery were assessed prospectively.

RESULTS

Six patients were excluded for protocol violations. Eleven (11 per cent) of 101 patients with stapled and five (5 per cent) of 98 who had diathermy haemorrhoidectomy had positive blood cultures for organisms after haemorrhoidectomy, predominantly anaerobes commonly found within the bacterial flora of the anorectum (P = 0.19). Transient postoperative pyrexia in several patients did not correlate with detected bacteraemia and settled spontaneously without treatment. There were no serious complications from either operative technique, and no clinical consequences from proven bacteraemia.

CONCLUSION

Transient bacteraemia may complicate surgical haemorrhoidectomy but has no serious clinical consequences for healthy adults.

A novel indicator for surveillance colonoscopy following colorectal cancer resection

INTRODUCTION

Current surveillance for recurrent intraluminal or metachronous colorectal cancer following resection is largely undertaken by colonoscopic examination of the remaining colon. The burden on colonoscopic services is high and the procedure is expensive. Immunological faecal occult blood testing (FOBT) is a sensitive and specific test for detecting colorectal cancer, and may fine tune the need for timely surveillance colonoscopy.

METHODS

Consecutive patients due for surveillance colonoscopy following colonic resection for cancer were prospectively studied. Each patient had a single faecal sample obtained at per rectal examination on a gloved examining finger. This was subjected to immunological FOBT in the clinic, and patients were categorized as FOBT positive or negative, according to the result. Colonoscopy as well as ultrasound or CT of the liver were performed within eight weeks of FOBT.

RESULTS

Six hundred and eleven patients had both FOBT and colonoscopy. Fifty-nine (13.6%) were categorized as FOBT-positive. Of these, nine had biopsy-proven recurrent or metachronous cancer, 12 patients had one, or more adenomatous polyps, one patient had radiation proctitis and two patients had pan-colonic mucositis following chemotherapy. In the remaining 552 FOBT-negative patients, no cancers were found. Thirty-eight patients had polyps that were removed. The sensitivity and specificity for detecting cancer by immunological FOBT was 100% sensitivity for detecting adenomatous polyps was 24% but specificity was 93%.

CONCLUSION

The immunological faecal occult blood test provides sensitive detection of metachronous and recurrent cancer in postoperative surveillance. Routine application may be used to reduce the frequency of colonoscopic surveillance, as a negative FOBT may be taken as a sign that colonoscopy may be deferred safely.

Optical orientation and femtosecond relaxation of spin-polarized holes in GaAs

Optical orientation of spin-polarized heavy and light holes followed by relaxation to other valence subband states has been observed unambiguously in undoped bulk GaAs in spite of the extremely short spin relaxation time. The measured relaxation time for the heavy holes is 110 fs +/-10%. The results are relevant for applications such as interpretation of spin-polarized transport in semiconductors as well as the assessment of feasibility of hole-based spin-transport devices which relies on precise knowledge of the hole-spin relaxation time.

Prospective, randomized trial comparing sigmoid vs. descending colonic J-pouch after total rectal excision

PURPOSE

The aim of this study was to compare the bowel function of sigmoid vs. descending colonic J-pouches after ultralow anterior resection for rectal cancer.

METHODS

A prospective, randomized trial was conducted from March 1998 to September 1999. Ninety-two consecutive patients undergoing ultralow anterior resection for cancers arising from 3 to 10 cm from the anal verge were recruited. Forty-eight patients were males; the mean ages (standard error of the mean) for patients with sigmoid and descending colon pouches, respectively, were 65.2 (3.1) years and 62.3 (3.1) years. A total of 46 patients were randomly assigned to each group. Two patients from each group were excluded; abdominoperineal resection was performed for two patients in the sigmoid pouch group and one patient in the descending pouch group. One patient in the descending pouch group had a transanal resection of a benign polyp. Dukes staging and use of postoperative chemoradiotherapy were statistically similar in both groups. All patients underwent a standardized ultralow anterior resection. A defunctioning loop ileostomy was used routinely. Anorectal physiology and bowel function questionnaires were performed at six weeks after ileostomy closure and again at 6 and 12 months after surgery.

RESULTS

Median follow-up was 12 (range, 7 to 25) and 12 (range, 6 to 25) months, respectively, for sigmoid and descending pouch groups. Median tumor and anastomotic heights, time to ileostomy closure, operative time, and postoperative stay were statistically similar in both groups. There were no significant differences in stool frequency, incontinence, urgency, use of pads and antidiarrheals, sensation of incomplete evacuation, and anorectal physiology results between groups (P > 0.05).

CONCLUSION

Pouches made from sigmoid or descending colon give similar bowel function after ultralow anterior resection for rectal cancers.

Prospective randomised trial comparing ayurvedic cutting seton and fistulotomy for low fistula-in-ano

The aim of this study was to evaluate the role of ayurvedic setons in the treatment of low fistula-in-ano. One hundred and eight patients were randomised into either conventional fistulotomy (F) or ayurvedic cutting seton insertion (C). Endpoints investigated included time to wound healing and complications of surgery. Post-operative pain scores were measured daily using a visual analog scale. Anal function was compared using a continence score. Pre- and postoperative manometry and ultrasound were also performed. After exclusions, there were 54 patients in group F and 46 in group C. There were no differences in age, sex or follow-up duration between the two groups. Healing time was similar between the groups. Group C reported more pain following operation and on the first 2-4 postoperative days, but both groups experienced the same amount of pain subsequently. In conclusion, chemical seton was more painful than conventional fistulotomy in the first few days following surgery. However, there was no difference in time to wound healing, complications or functional outcome.

A prospective randomised study of drains in infra-peritoneal rectal anastomoses

Although increasing evidence suggests that prophylactic drainage after intra-peritoneal colorectal anastomoses is unnecessary, drains for infra-peritoneal rectal anastomoses, where the leak rate is higher, are widely employed still. The aim of this study was to assess the effect of prophylactic drainage after anastomosis below the peritoneal reflection. All patients attending one specialist unit over an 8-month period for elective rectal cancer resection with an infra-peritoneal anastomosis were randomised to drainage or no drainage. The incidence of anastomotic leak and complications specific to the drain as well as other complications were compared. Fifty-nine patients were analysed (31 with drain). Twenty-five of the drained and 16 of the no-drain patients had a defunctioning stoma (p=ns). The groups were comparable for demographic data, operation and anastomotic height from the anal verge. There were three leaks (10%) in the drain group and five leaks (18%) in the no-drain group (p=ns). There were 2 (7%) patients in each group with a clinical leak. There were no specific drain complications and the incidence of other complications was similar in both groups. In conclusion, this study supports the contention that there is no difference in morbidity with or without the use of a drain for infra-peritoneal anastomoses.

Mutation-tolerant protein identification by mass spectrometry

Database search in tandem mass spectrometry is a powerful tool for protein identification. High-throughput spectral acquisition raises the problem of dealing with genetic variation and peptide modifications within a population of related proteins. A method that cross-correlates and clusters related spectra in large collections of uncharacterized spectra (i.e., from normal and diseased individuals) would be very valuable in functional proteomics. This problem is far from being simple since very similar peptides may have very different spectra. We introduce a new notion of spectral similarity that allows one to identify related spectra even if the corresponding peptides have multiple modifications/mutations. Based on this notion, we developed a new algorithm for mutation-tolerant database search as well as a method for cross-correlating related uncharacterized spectra.

Randomized clinical trial of the effect of open versus laparoscopically assisted colectomy on systemic immunity in patients with colorectal cancer

BACKGROUND

Laparoscopic surgery is believed to produce an attenuated metabolic stress response and to have a less dampening effect on the immune response than open surgery. To date, the effect has not been studied in a randomized clinical trial of colorectal cancer.

METHODS

The study was a two-armed randomized prospective trial conducted in parallel with the UK Medical Research Council's Conventional versus Laparoscopic-Assisted Surgery in Colorectal Cancer (CLASICC) trial comparing laparoscopically assisted colorectal surgery for left-sided tumours with conventional open surgery. Systemic immunity was assessed by determining the T- and B-cell counts, the CD4 : CD8 ratio, the natural killer cell counts, the immunoglobulin (Ig) G, IgM and IgA levels, and C3 and C4 levels. The white cell phagocytic activity (nitroblue tetrazolium test) was studied before operation and on the third postoperative day.

RESULTS

A total of 236 patients were randomized in the immune study between 11 March 1997 and 14 August 1999; 161 had complete preoperative and postoperative assays for the analysis of results. There was no difference in mean response between the two surgical groups for each of the immune parameters studied. The unadjusted difference for the primary endpoint, T-cell count, 3 days after operation was - 1.6 per cent (95 per cent confidence interval - 5.0 to 1.8 per cent).

CONCLUSION

There is no difference in the systemic immune response in patients having laparoscopically assisted colectomy compared with those undergoing conventional open surgery for colorectal cancer.