Intravitreal aflibercept 8 mg in neovascular age-related macular degeneration (PULSAR): 48-week results from a randomised, double-masked, non-inferiority, phase 3 trial

BACKGROUND

Intravitreal aflibercept 8 mg could improve treatment outcomes and provide sustained disease control in patients with neovascular age-related macular degeneration (nAMD), with extended dosing compared with aflibercept 2 mg.

METHODS

PULSAR is a phase 3, randomised, three-group, double-masked, non-inferiority, 96-week trial conducted across 223 sites worldwide. Adults with nAMD were randomised 1:1:1 to aflibercept 8 mg every 12 weeks (8q12), aflibercept 8 mg every 16 weeks (8q16), or aflibercept 2 mg every 8 weeks (2q8), following three initial monthly doses in all groups. From week 16, patients in the aflibercept 8 mg groups had their dosing interval shortened if pre-specified dose regimen modification criteria denoting disease activity were met. The primary endpoint was change from baseline in best-corrected visual acuity (BCVA) at week 48. All patients with at least one dose of study treatment were included in the efficacy and safety analyses. This trial is registered with ClinicalTrials.gov (NCT04423718) and is ongoing.

FINDINGS

Of 1011 patients randomised to aflibercept 8q12 (n=336), 8q16 (n=338), or 2q8 (n=337) between Aug 11, 2020, and July 30, 2021, 1009 patients received study treatment (aflibercept 8q12 n=335; aflibercept 8q16 n=338; and aflibercept 2q8 n=336). Aflibercept 8q12 and 8q16 showed non-inferior BCVA gains versus aflibercept 2q8 (mean BCVA change from baseline +6·7 [SD 12·6] and +6·2 [11·7] vs +7·6 [12·2] letters). The least squares mean differences between aflibercept 8q12 versus 2q8 and 8q16 versus 2q8, respectively, were -0·97 (95% CI -2·87 to 0·92) and -1·14 (-2·97 to 0·69) letters (non-inferiority margin at 4 letters). The incidence of ocular adverse events in the study eye was similar across groups (aflibercept 8q12 n=129 [39%]; aflibercept 8q16 n=127 [38%]; and aflibercept 2q8 n=130 [39%]).

INTERPRETATION

Aflibercept 8 mg showed efficacy and safety with extended dosing intervals, which has the potential to improve the management of patients with nAMD.

FUNDING

Bayer AG and Regeneron Pharmaceuticals.

Intravitreal aflibercept 8 mg in diabetic macular oedema (PHOTON): 48-week results from a randomised, double-masked, non-inferiority, phase 2/3 trial

BACKGROUND

A high-dose formulation of intravitreal aflibercept (8 mg) could improve treatment outcomes in diabetic macular oedema (DMO) by requiring fewer injections than the standard comparator, aflibercept 2 mg. We report efficacy and safety results of aflibercept 8 mg versus 2 mg in patients with DMO.

METHODS

PHOTON was a randomised, double-masked, non-inferiority, phase 2/3 trial performed at 138 hospitals and specialty retina clinics in seven countries. Eligible patients were adults aged 18 years or older with type 1 or 2 diabetes and centre-involved DMO. Patients were randomly assigned (1:2:1) to intravitreal aflibercept 2 mg every 8 weeks (2q8), aflibercept 8 mg every 12 weeks (8q12), or aflibercept 8 mg every 16 weeks (8q16), following initial monthly dosing. From week 16, dosing intervals for the aflibercept 8 mg groups were shortened if patients met prespecified dose regimen modification criteria denoting disease activity. The primary endpoint was change from baseline in best-corrected visual acuity (BCVA) at week 48 (non-inferiority margin of 4 letters). Efficacy and safety analyses included all randomly assigned patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov (NCT04429503).

FINDINGS

Between June 29, 2020, and June 28, 2021, 970 patients were screened for eligibility. After exclusions, 660 patients were enrolled and randomly assigned to receive aflibercept 8q12 (n=329), 8q16 (n=164), or 2q8 (n=167); two patients were randomly assigned in error and did not receive treatment. 658 (99·7%) patients were treated and included in the full analysis set and safety analysis set (8q12 n=328, 8q16 n=163, and 2q8 n=167). Mean patient age was 62·3 years (SD 10·4). 401 (61%) patients were male. 471 (72%) patients were White. Aflibercept 8q12 and 8q16 demonstrated non-inferior BCVA gains to aflibercept 2q8 (BCVA mean change from baseline 8·8 letters [SD 9·0] in the 8q12 group, 7·9 letters [8·4] in the 8q16 group, and 9·2 letters [9·0] in the 2q8 group). The difference in least squares means was -0·57 letters (95% CI -2·26 to 1·13, p value for non-inferiority <0·0001) between 8q12 and 2q8 and -1·44 letters (-3·27 to 0·39, p value for non-inferiority 0·0031) between aflibercept 8q16 and 2q8. Proportions of patients with ocular adverse events in the study eye were similar across groups (8q12 n=104 [32%], 8q16 n=48 [29%], and 2q8 n=46 [28%]).

INTERPRETATION

Aflibercept 8 mg demonstrated efficacy and safety with extended dosing intervals and could decrease treatment burden in patients with DMO.

FUNDING

Regeneron Pharmaceuticals and Bayer.

Effect of High-Dose Intravitreal Aflibercept, 8 mg, in Patients With Neovascular Age-Related Macular Degeneration: The Phase 2 CANDELA Randomized Clinical Trial

Importance

Aflibercept, 8 mg, may have greater therapeutic benefits compared with aflibercept, 2 mg, in patients with neovascular age-related macular degeneration (nAMD), including potentially improved outcomes and decreased treatment burden.

Objective

To assess safety and efficacy of aflibercept, 8 mg, in patients with nAMD.

Design, Setting, and Participants

The CANDELA trial was a phase 2, randomized, single-masked, open-label, 44-week clinical trial conducted in the US. Treatment-naive patients with active subfoveal choroidal neovascularization secondary to nAMD and a best-corrected visual acuity score of 78 to 24 letters (approximately 20/32 to 20/320) in the study eye were enrolled between November 2019 and November 2021.

Interventions

Eligible participants were randomized 1:1 to receive 3 monthly doses of 8 mg (70 μL) or 2 mg (50 μL) of aflibercept followed by doses at weeks 20 and 32.

Main Outcomes and Measures

Coprimary end points were the proportion of eyes without fluid (absence of intraretinal and subretinal fluid) in the central subfield at week 16 and safety.

Results

All 106 eligible eyes were randomized to receive aflibercept, 8 mg (n = 53), or aflibercept, 2 mg (n = 53). Overall, 66 participants (62.3%) were female. The proportion of eyes without fluid in the central subfield with 8-mg vs 2-mg aflibercept was 50.9% (n = 27) vs 34.0% (n = 18) (difference, 17.0 [95% CI, -1.6 to 35.5] percentage points; P = .08) at week 16 and 39.6% (n = 21) vs 28.3% (n = 15) (difference, 11.3 [95% CI, -6.6 to 29.2] percentage points; nominal P = .22) at week 44. At week 44, mean (SE) change in central retinal thickness was -159.4 (16.4) vs -137.2 (22.8) μm with 8 mg vs 2 mg of aflibercept, respectively (least squares mean difference, -9.5 [95% CI, -51.4 to 32.4]; nominal P = .65) and mean (SE) change in best-corrected visual acuity score was +7.9 (1.5) vs +5.1 (1.5) letters (least squares mean difference, +2.8 [95% CI, -1.4 to +7.0]; nominal P = .20). No differences in safety profiles between the groups were observed.

Conclusions and Relevance

Although aflibercept, 8 mg, did not achieve the primary efficacy end point at week 16 at the 2-sided significance level of 5%, the observed trends in anatomic and visual improvements over 44 weeks with aflibercept, 8 mg, indicate potential additional therapeutic benefit over aflibercept, 2 mg. No new safety signals were observed over 44 weeks. These findings support further evaluation of aflibercept, 8 mg, in pivotal trials of exudative retinal diseases including nAMD and diabetic macular edema.

Trial Registration

ClinicalTrials.gov Identifier: NCT04126317.

Intravitreal Nesvacumab (Anti-Angiopoietin-2) Plus Aflibercept in Neovascular AMD: Phase 2 ONYX Randomized Trial

Purpose:

To compare intravitreal nesvacumab (anti-angiopoietin-2) + aflibercept vs intravitreal aflibercept injection (IAI) in neovascular age-related macular degeneration (nAMD).

Methods:

Eyes were randomized (1:2:3) to nesvacumab 3 mg + aflibercept 2 mg (LD combo), nesvacumab 6 mg + aflibercept 2 mg (HD combo), or IAI 2 mg at baseline, week 4, and week 8. The LD combo was continued every 8 weeks (q8w). At week 12, the HD combo was re-randomized to q8w or every 12 weeks (q12w) and IAI was re-randomized to q8w, q12w, or HD combo q8w through week 32.

Results:

The study comprised 365 eyes. At week 12, the mean best-corrected visual acuity (BCVA) gains from baseline were similar in the LD combo group, HD combo group, and IAI group (5.2 letters, 5.6 letters, and 5.4 letters, respectively); the mean central subfield thickness (CST) reductions were similar (182.2 µm, 200.0 µm, and 178.6 µm, respectively). The mean changes in BCVA and CST through week 36 were similar across groups. At week 12, complete retinal fluid resolution was observed in 49.1% (LD combo), 50.8% (HD combo), and 43.6% (IAI) of eyes; the proportions with a CST of 300 μm or less were similar across groups. Numerical trends at week 32 toward complete retinal fluid resolution with combination treatment were not maintained at week 36. Serious ocular adverse events were infrequent and comparable across groups.

Conclusions:

In nAMD, nesvacumab + aflibercept showed no additional BCVA or CST benefit over IAI monotherapy.

Intravitreal Combined Aflibercept + Anti-Platelet-Derived Growth Factor Receptor β for Neovascular Age-Related Macular Degeneration: Results of the Phase 2 CAPELLA Trial

PURPOSE

To compare the efficacy and safety of intravitreal aflibercept + anti-platelet-derived growth factor receptor β (PDGFRβ) combination with intravitreal aflibercept injection (IAI) monotherapy in patients with treatment-naïve neovascular age-related macular degeneration (nAMD).

DESIGN

Phase 2, randomized, double-masked study.

PARTICIPANTS

A total of 505 patients (eyes) with nAMD.

METHODS

Patients were randomized 1:2:2 to low-dose combination intravitreal anti-PDGFRβ 1 mg and aflibercept 2 mg (LD combo), high-dose combination intravitreal anti-PDGFRβ 3 mg and aflibercept 2 mg (HD combo), or IAI alone every 4 weeks through week 12. At week 12, patients in the HD combo and IAI groups were re-randomized to continue as assigned or switch to HD combo → IAI or IAI → HD combo and dosed every 4 weeks through week 28. During weeks 28 to 52, patients received treatment as needed per prespecified criteria. This report presents efficacy through week 28 and safety through week 52.

MAIN OUTCOME MEASURES

Mean best-corrected visual acuity (BCVA) change from baseline at week 12 (primary end point).

RESULTS

At week 12, mean BCVA gains from baseline were 5.8, 5.8, and 7.5 letters with LD combo, HD combo, and IAI, respectively (P = 0.21 for LD combo and P = 0.10 for HD combo vs. IAI). The corresponding proportions of eyes that gained ≥15 letters were 12%, 19%, and 22%, respectively. Mean reductions in central retinal thickness from baseline were 126.1, 127.1, and 126.9 μm, respectively. Proportions of eyes with complete resolution of fluid from baseline were 35%, 24%, and 42%, respectively. Vision and anatomic outcomes at week 28 were consistent with the week 12 results. Through week 52, the incidence of intraocular inflammation was 1.0%, 7.5%, 2.1%, 2.1%, and 0%, respectively. The incidence of Anti-Platelet Trialists' Collaboration-defined arterial thromboembolic events was 1.9%, 0.9%, 1.1%, 2.1%, and 1.9%, respectively.

CONCLUSIONS

Intravitreal aflibercept + anti-PDGFRβ did not improve BCVA over IAI alone. Anatomic outcomes evaluating complete fluid resolution favored IAI. Adverse events were consistent with the reported IAI safety profile, except for a higher frequency of intraocular inflammation in the HD combo group.

Long-term Safety and Visual Outcome of Intravitreal Aflibercept in Neovascular Age-Related Macular Degeneration: VIEW 1 Extension Study

PURPOSE

To assess the long-term safety and vision change in patients who received intravitreal aflibercept injection (IAI) for neovascular age-related macular degeneration in an extension study after completing VIEW 1 trial.

DESIGN

Prospective, open-label, multicenter, extension study.

PARTICIPANTS

Three hundred twenty-three patients.

METHODS

In VIEW 1, 1217 patients were randomized to receive fixed dosing of 0.5 mg IAI every 4 weeks (0.5q4), 2 mg IAI every 4 weeks (2q4), 2 mg IAI every 8 weeks after 3 initial monthly dosing (2q8), or 0.5 mg ranibizumab every 4 weeks (Rq4) from baseline through week 52, followed by modified quarterly injections of the same dose of anti-vascular endothelial growth factor agent from weeks 52 to 96. After completing VIEW 1 at week 96, patients (n = 323) enrolled in an extension study and received 2 mg IAI on a modified quarterly injection schedule followed by at least an every 8-week dosing through week 212.

MAIN OUTCOME MEASURES

Long-term safety and vision change in patients followed for a median duration of 116 weeks in the extension study (total follow-up time of 212 weeks from the VIEW 1 baseline).

RESULTS

Patients enrolled in the extension study gained a mean of 10.2 letters from the VIEW 1 baseline at week 96. These patients largely maintained vision over the extension study with a mean gain of 7.1 letters from the VIEW 1 baseline to week 212. The proportion of patients who lost ≥15 letters from the VIEW 1 extension baseline was 8.2% at week 212. Mean number of injections was 12.9 (range, 1-41) in the extension study. The most common serious ocular adverse event was endophthalmitis (0.9%). The overall incidence of Antiplatelet Trialists' Collaboration-defined arterial thromboembolic events was 6.2%.

CONCLUSIONS

Vision gains achieved with anti-vascular endothelial growth factor therapy in VIEW 1 were largely maintained by continued treatment with IAI 2 mg in the extension study. Anti-vascular endothelial growth factor injections (including 4 years of IAI 2 mg) were well-tolerated with no new safety signals compared with the known profile of IAI.

Intravitreal Aflibercept for Macular Edema Following Branch Retinal Vein Occlusion: 52-Week Results of the VIBRANT Study

PURPOSE

To determine week 52 efficacy and safety outcomes in eyes with macular edema after branch retinal vein occlusion (BRVO) treated with 2 mg intravitreal aflibercept injection (IAI) compared with grid laser.

DESIGN

VIBRANT was a double-masked, randomized, phase 3 trial.

PARTICIPANTS

Eyes randomized and treated in VIBRANT were followed to week 52.

METHODS

In the IAI group, eyes received IAI every 4 weeks through week 24 and IAI every 8 weeks through week 48 with rescue grid laser if needed at week 36. In the grid laser group, all eyes received grid laser at baseline and, if prespecified rescue criteria were met, 1 additional laser from week 12 to 20 and IAI every 8 weeks after 3 monthly doses from week 24 onward (the laser/IAI group).

MAIN OUTCOME MEASURES

The primary outcome measure was percentage of eyes with improvement from baseline best-corrected visual acuity (BCVA) letter score ≥15 at week 24. All outcome measures at week 52 were exploratory, and P values are considered nominal.

RESULTS

The percentage of eyes with improvement from baseline letter score ≥15 in the IAI and laser/IAI groups was 52.7% versus 26.7% (P = 0.0003) at week 24 and 57.1% versus 41.1% (P = 0.0296) at week 52. The corresponding mean change from baseline BCVA letter score was 17.0 versus 6.9 (P < 0.0001) at week 24 and 17.1 versus 12.2 (P = 0.0035) at week 52. The mean reduction from baseline central retinal thickness was 280.5 μm versus 128.0 μm (P < 0.0001) at week 24 and 283.9 μm versus 249.3 μm (P = 0.0218) at week 52. In the IAI group, 10.6% of eyes received rescue laser at week 36, and in the laser/IAI group, 80.7% received rescue IAI from week 24 to week 48. Traumatic cataract in 1 eye (1.1%) in the IAI group was the only ocular serious adverse event.

CONCLUSIONS

After 6 monthly IAI, injections every 8 weeks maintained control of macular edema and visual benefits through week 52. In the laser group, rescue IAI given from week 24 onward resulted in substantial visual improvements at week 52.

Intravitreal aflibercept for macular edema following branch retinal vein occlusion: the 24-week results of the VIBRANT study

PURPOSE

To compare the efficacy and safety of intravitreal aflibercept injection (IAI) with macular grid laser photocoagulation for the treatment of macular edema after branch retinal vein occlusion (BRVO).

DESIGN

The VIBRANT study was a double-masked, active-controlled, randomized, phase III trial.

PARTICIPANTS

Treatment-naïve eyes with macular edema after BRVO were included in the study if the occlusion occurred within 12 months and best-corrected visual acuity (BCVA) was between ≤73 and ≥24 Early Treatment Diabetic Retinopathy Study (ETDRS) letters (20/40-20/320 Snellen equivalent).

METHODS

Eyes (1 eye per patient) received either IAI 2 mg every 4 weeks (n=91) from baseline to week 20 or grid laser (n=92) at baseline with a single grid laser rescue treatment, if needed, from weeks 12 through 20.

MAIN OUTCOME MEASURES

The primary outcome measure was the proportion of eyes that gained ≥15 ETDRS letters from baseline BCVA at week 24. Secondary end points included mean change from baseline BCVA and central retinal thickness (CRT) at week 24.

RESULTS

The proportion of eyes that gained ≥15 ETDRS letters from baseline at week 24 was 52.7% in the IAI group compared with 26.7% in the laser group (P=0.0003). The mean improvement from baseline BCVA at week 24 was 17.0 ETDRS letters in the IAI group and 6.9 ETDRS letters in the laser group (P<0.0001). The mean reduction in CRT from baseline at week 24 was 280.5 μm in the IAI group and 128.0 μm in the laser group (P<0.0001). Traumatic cataract in an IAI patient was the only ocular serious adverse event (SAE) that occurred. There were no cases of intraocular inflammation or endophthalmitis. The incidence of nonocular SAEs was 8.8% in the IAI group and 9.8% in the laser group. One Anti-Platelet Trialists' Collaboration-defined event of nonfatal stroke (1.1%) and 1 death (1.1%) due to pneumonia occurred during the 24 weeks of the study, both in patients in the laser group.

CONCLUSIONS

Monthly IAI provided significantly greater visual benefit and reduction in CRT at 24 weeks than grid laser photocoagulation in eyes with macular edema after BRVO.

Seroepidemiology of Middle East respiratory syndrome (MERS) coronavirus in Saudi Arabia (1993) and Australia (2014) and characterisation of assay specificity

The pseudoparticle virus neutralisation test (ppNT) and a conventional microneutralisation (MN) assay are specific for detecting antibodies to Middle East respiratory syndrome coronavirus (MERS-CoV) when used in seroepidemiological studies in animals. Genetically diverse MERS-CoV appear antigenically similar in MN tests. We confirm that MERS-CoV was circulating in dromedaries in Saudi Arabia in 1993. Preliminary data suggest that feral Australian dromedaries may be free of MERS-CoV but larger confirmatory studies are needed.

Plasma Epstein-Barr viral DNA load at midpoint of radiotherapy course predicts outcome in advanced-stage nasopharyngeal carcinoma

BACKGROUND

To test the hypothesis that prognostication of treatment outcome is feasible by biomarker response at midcourse of chemoradiotherapy (CRT)/radiotherapy (RT), with respect to the plasma load of Epstein-Barr viral (EBV) DNA in nasopharyngeal carcinoma (NPC).

PATIENTS AND METHODS

One hundred seven patients with stage IIB-IV NPC were prospectively studied. Plasma EBV DNA load was measured by quantitative PCR before therapy (pre-DNA), at completion of 4 weeks of CRT/RT (mid-DNA), and within 3 months of completion of therapy (post-DNA). The end points are post-DNA load, a recognized surrogate of survival, and clinical outcome.

RESULTS

Ninety-three percent of patients had detectable EBV DNA before therapy (median load = 972 copies/ml). EBV DNA became undetectable in 55 (51%) patients at the end of week 4 of therapy. Detectable mid-DNA was associated with worse clinical outcome (median follow-up time, 6.2 years), for distant failure [hazard ratio (HR) 12.02, 95% confidence interval (CI) 2.78-51.93; P < 0.0001], progression-free survival (PFS; HR 4.05, 95% CI 1.89-8.67, P < 0.0001), and overall survival (OS; HR 3.29, 95% CI 1.37-7.90, P = 0.0077). Seventy-four percent of all failures were associated with detectable mid-DNA, whereas 34% of all failures were associated with detectable post-DNA. Stratification by tumor stage (IIB, III, IV) has no significant prognostic effect.

CONCLUSIONS

Unfavorable EBV DNA response at midcourse of RT/CRT is an adverse prognosticator for treatment outcome, is linked to majority of all failures, and discriminates outcome better than tumor stage. The data could provide a basis for trial design that addresses alteration of therapy intensity during the latter phase of CRT, and adjuvant therapy. Validation studies are awaited.

Study of wrist posture, loading and repetitive motion as risk factors for developing carpal tunnel syndrome

Occupational risk factors of carpal tunnel syndrome (CTS) are popular current research targets, with main emphasis put on wrist posture and dynamics. In this study, we do not intend to pinpoint individual occupations, but aim to identify high risk wrist postures and actions which may occur across various occupations. It is hoped that prevention can thus be instituted in a general population by directing at the particular causative wrist actions rather than exclusively targeting isolated occupations. We performed a case-control study with 166 cases and 111 controls recruited from different hospitals in Hong Kong in 2004. All cases and controls completed the survey on their general health condition, smoking status, wrist posture and motion as well as psychosocial status at the time of diagnosis of CTS. Frequent flexion OR = 4.436 (95% CI: 1.833-10.734), frequent extension OR = 2.691 (95% CI: 1.106-6.547) of the wrist were found to be associated with CTS. Frequent sustained forceful motion of the wrist OR = 2.588 (95% CI: 1.144-5.851) was also found to be associated with CTS. Neutral wrist position and repetitive wrist motion were not associated with CTS. Adjustment was made for age, sex, BMI, smoking and psychosocial stress. Our study confirms that frequent flexion, extension and sustained force of the wrist increase the risk of developing CTS.

Previous abdominal operations do not affect the outcomes of laparoscopic colorectal surgery

BACKGROUND

Previous abdominal surgery has been regarded as a relative contraindication for laparoscopic surgery. However, studies on laparoscopic cholecystectomy have showed that the presence of prior abdominal procedures does not affect the outcomes of surgery. This study aimed to investigate the impact of previous abdominal surgery on laparoscopic colorectal surgery.

METHODS

This study enrolled 295 consecutive patients who underwent laparoscopic colorectal surgery from May 2000 to May 2003. The patients were divided into two groups: those with previous abdominal surgery (n = 84) and those without a prior operation (n = 211). The outcomes of surgery for the two groups were compared with respect to the duration of surgery, blood loss, conversion rate, time to return of bowel function, resumption of diet, complications, and the hospital stay.

RESULTS

The study included 158 men and 137 women. The median age of the patients was 70 years (range, 33-91 years). Significantly more female patients and patients with benign diseases had prior abdominal surgery. Conversion was required for 17.8% of the patients with and 11.4% of the patients without previous surgery (p = 0.181). There were no differences in the operating time or blood loss between the two groups. The time to bowel movement and resumption of diet were similar in the two groups. The median hospital stay was 7 days for both groups. Of the 39 conversions, 28.2% were necessitated mainly by the presence of adhesions. In the patients who underwent conversion because of adhesions (n = 11), nine had prior surgery and two did not (p = 0.001).

CONCLUSIONS

The presence of prior surgery does not affect the operating time or blood loss of patients undergoing laparoscopic colorectal surgery. The conversion rate is not increased for patients with prior surgery. The postoperative outcomes in terms of ileus, complication rate, and hospital stay are not worse for patients with prior surgery. Previous abdominal surgery should not be considered as a contraindication for laparoscopic colorectal surgery.

Abdominoperineal resection is associated with poor oncological outcome

BACKGROUND

The aim of this study was to compare the operative results and oncological outcomes of patients who had mid or distal rectal cancer treated by abdominoperineal resection (APR) with those treated without sphincter ablation (non-APR).

METHODS

Five hundred and four consecutive patients (308 men and 196 women) with rectal cancer within 12 cm from the anal verge underwent radical resection with curative intent. Sharp mesorectal dissection was used. Operative results and long-term outcomes were compared between those treated by APR and those by non-APR.

RESULTS

Sixty-nine patients had APR and 435 patients were treated with radical resection without perineal resection (anterior resection, 419; Hartmann's operation, 16). The overall operative mortality and morbidity rates were 1.6 and 31.0 per cent respectively. Age, sex, duration of surgery, blood loss, duration of hospital stay, operative mortality and overall morbidity were similar in the two groups. Local recurrence was more frequent after curative APR than after non-APR (23 versus 10.2 per cent at 5 years; P = 0.010). Five-year cancer-specific survival rates after APR and non-APR were 60 and 74.0 per cent respectively (P = 0.006). APR was an independent factor for poor cancer-specific survival in multivariate analysis.

CONCLUSION

Although postoperative mortality and morbidity rates were similar in patients with or without sphincter ablation, local control and survival were worse in those treated by APR.

Early outcomes of 100 patients with laparoscopic resection for rectal neoplasm

BACKGROUND

Laparoscopic resection has been shown to be a feasible option in patients with colorectal diseases. However, there have been only a few studies on laparoscopic resection for rectal neoplasm. This report aimed to evaluate the early outcomes of patients treated by laparoscopic rectal resection for neoplasm.

METHODS

From May 2000 to April 2003, 100 patients underwent laparoscopic resection for rectal neoplasm with mesorectal excision. Data on the patients' demographics, operative details, and outcomes were collected prospectively. In those with successful laparoscopic resection, comparison was made between patients with predominantly intracorporeal surgery (ICS) and those with anterior resection performed with extracorporeal rectal transection and anastomosis following intracorporeal bowel mobilization and vessel ligation (IECS).

RESULTS

Sixty-six men and 34 women (median age, 69 years; range, 40-85) were included. Operations included 91 anterior resections, eight abdominoperineal resections, and one Hartmann's procedure. Conversion was required in 15 patients and no conversion was needed in patients treated by laparoscopic abdominoperineal resection. One patient died 30 days after surgery because of liver failure. Postoperative complications occurred in 31 patients. Among them, three had anastomotic leakage and all of them could be treated conservatively. Reoperation was required in one patient with intestinal obstruction. Patients with conversion were found to have significantly more blood loss, longer time to resume diet, a longer hospital stay, and a higher morbidity rate when compared to those with successful laparoscopic surgery. Among those with successful laparoscopic procedures, no difference was observed between patients with ICS (n = 57) and those with IECS (n = 28), except that a shorter incision and less blood loss were found in patients in the former group.

CONCLUSIONS

Laparoscopic rectal resection with mesorectal dissection is feasible. The operating mortality and reoperation rates were low. Conversion was associated with an increased morbidity rate, leading to a longer hospital stay. Laparoscopically assisted anterior resection with rectal transection by a transverse stapler through the abdominal incision produced similar results when compared to a procedure that was predominantly intracorporeally performed.

Comparison of stenting with emergency surgery as palliative treatment for obstructing primary left-sided colorectal cancer

BACKGROUND

Self-expanding metallic stents provide an alternative to surgery as definitive palliation in patients with obstructing colorectal cancer. This study aimed to compare the outcome of patients with obstruction due to primary left-sided colorectal cancer treated by palliative stenting with outcome in patients who had undergone surgery.

METHODS

Patients with incurable obstructing primary colorectal cancer distal to the splenic flexure treated with emergency surgery (n = 31) or placement of a metallic stent (n = 30) from November 1997 to June 2002 were included. Data on the mortality, morbidity, necessity of intensive care and hospital stay for the two groups were compared. The subsequent outcomes, including the incidence of stoma creation and survival, were also analysed.

RESULTS

The two groups were similar in terms of age, sex distribution and presence of co-morbidity. Insertion of metallic stents was successful in 29 of 30 patients. Hospital death occurred in four and eight patients in the study and control groups respectively (P = 0.335). Fewer patients with placement of a stent required intensive care (1 versus 11; P = 0.001) and the median hospital stay was shorter in patients with stenting (4 versus 8 days; P = 0.008). A stoma was subsequently created in four patients with stenting, whereas 15 patients who had emergency operation required a stoma (P = 0.005). The difference in median survival between the two groups was not statistically significant (107 versus 119 days; P = 0.088).

CONCLUSION

Self-expanding metallic stents are effective in the palliation of obstructing colorectal cancer. Placement of stents is associated with a shorter hospital stay, less likelihood of intensive care and a lower incidence of stoma creation, when compared with emergency surgery. Thus insertion of a metallic stent should be considered in patients with incurable obstructing colorectal cancer.

A sensitive guaiac faecal occult blood test is less useful than an immunochemical test for colorectal cancer screening in a Chinese population

BACKGROUND

Colorectal cancer screening by guaiac faecal occult blood test has been shown to reduce the incidence and mortality of colorectal cancer in Western populations. The optimal faecal occult blood test, whether guaiac or immunochemical, for colorectal cancer screening in the Chinese population remains to be defined.

AIM

To compare the performance characteristics of a sensitive guaiac-based faecal occult blood test (Hemoccult SENSA) and an immunochemical faecal occult blood test (FlexSure OBT) in a Chinese population referred for colonoscopy.

METHODS

One hundred and thirty-five consecutive patients who were referred for colonoscopy and who met the study inclusion criteria took samples for the two faecal occult blood tests simultaneously from three successive stool specimens, with no dietary restrictions. All tests were developed and interpreted by a single experienced technician who was blind to the clinical diagnosis. The sensitivity, specificity and positive predictive value for the detection of colorectal adenomas and cancers were estimated for the two tests.

RESULTS

The sensitivity, specificity and positive predictive value for the detection of significant colorectal neoplasia (adenomas > or = 1.0 cm and cancers) were 91%, 70% and 18% for Hemoccult SENSA and 82%, 94% and 47% for FlexSure OBT. The specificity and positive predictive value were significantly higher for FlexSure OBT than for Hemoccult SENSA (P < 0.001 and P = 0.016, respectively). Combining the positive results from both faecal occult blood tests did not improve the accuracy.

CONCLUSION

The positive predictive value of the immunochemical faecal occult blood test for the detection of significant colorectal neoplasia was 29% better than that of the sensitive guaiac-based test. This may relate to the Chinese diet and requires further study. The poor specificity of the sensitive guaiac-based test, without dietary restriction, makes it less useful for colorectal cancer screening in a Chinese population.

The value of flexible sigmoidoscopy for patients with bright red rectal bleeding

OBJECTIVE

To review the diagnostic yield of flexible sigmoidoscopy in patients presenting with bright red rectal bleeding.

DESIGN

Retrospective study.

SETTING

University teaching hospital, Hong Kong.

SUBJECTS AND METHODS

Patients who underwent flexible sigmoidoscopy between January 1995 and April 1996 for investigation of bright red rectal bleeding were recruited. The extent of the endoscopic examination, complications, and endoscopic findings were recorded.

RESULTS

A total of 1052 patients were included in the study. The mean length of endoscopic examination was 55 cm. There were no complications attributed to the procedure. Thirteen (1.2%) patients aged from 41 to 87 years were found to have malignant tumours that were not palpable on digital examination. All the tumours were moderately differentiated adenocarcinoma. Two patients had synchronous liver metastasis at presentation. Adenomatous polyps were detected in 81 (7.7%) patients, of whom 76 were older than 40 years. The majority of polyps were tubular adenomas associated with mild or moderate dysplasia. Other endoscopic findings included hyperplastic and juvenile polyps, proctocolitis, diverticulosis, irradiation colitis, ischaemic colitis, rectal ulcers, and infective colitis. The overall diagnostic yield was 21.1%. No mucosal lesion was detected by flexible sigmoidoscopy in 78.9% of patients in whom the rectal bleeding was due to either haemorrhoids or anal fissure.

CONCLUSIONS

Cancer was detected in 1.2% and adenomatous polyps in 7.7% of patients with bright red rectal bleeding using flexible sigmoidoscopy. All cancers and 94% of adenomatous polyps were detected in patients older than 40 years. Flexible sigmoidoscopy appears to be a valuable initial investigation for bright red rectal bleeding in patients older than 40 years.

Ambulatory stapled haemorrhoidectomy: a safe and feasible surgical technique

OBJECTIVE

To compare outcomes following stapled haemorrhoidectomy as an in-patient versus day-surgery procedure.

DESIGN

Prospective non-randomised study.

SETTING

University affiliated hospitals, Hong Kong.

SUBJECTS AND METHODS

Forty-eight consecutive patients who underwent stapled haemorrhoidectomy were included in the study. Twenty-four patients had the procedure in an ambulatory setting and the other 24 were treated as in-patients. The symptoms, operative details, postoperative complications, length of hospital stay, pain scores, analgesic requirements, and patient satisfaction scores were collected. Comparison was made between those patients undergoing ambulatory surgery and those treated as in-patients.

RESULTS

There were 25 women and 23 men in the study. The mean age was 46.6 years (standard deviation, 12.1 years). The mean operating time was 29.3 minutes (standard deviation, 9.9 minutes). An incomplete 'doughnut' after stapling was found in one patient. There were no other adverse intra-operative events or complications. Postoperative morbidities occurred in eight patients but none required further surgery. One patient in the day-surgery group could not be discharged because of urinary retention and three required re-admission to hospital because of secondary haemorrhage (n=1) or fever (n=2). There were no differences in the postoperative complications, pain scores, analgesic requirements, and patient satisfaction scores between the two groups. The total mean hospital stay was significantly shorter for those undergoing day-surgery stapled haemorrhoidectomy (0.46 versus 1.9 days, P<0.01). The mean follow-up period was 4.6 months (standard deviation, 4.0 months). All patients reported symptomatic improvement during this time and there was no incidence of faecal incontinence. One patient had a soft stricture, one had a fissure, and two had residual skin tags. All of these problems were conservatively managed, without the need for further surgical procedures.

CONCLUSIONS

Stapled haemorrhoidectomy is a safe and effective operation for haemorrhoids. It is a feasible procedure to perform as day-surgery. The hospital stay can be significantly shortened, thus reducing the costs associated with in-patient care.

Radiation stricture of rectosigmoid treated with self-expanding metallic stent

Radiation stricture of the rectosigmoid with obstruction is a difficult clinical problem, and surgery is associated with high mortality and morbidity. We report a case involving radiation stricture of the rectosigmoid in an 80-year-old woman who presented with acute colonic obstruction. A self-expanding metallic stent was successfully inserted, and the obstruction was relieved. The stent remained patent for 4 months without any complications until the patient died of sepsis resulting from pneumonia and bedsores. The literature on the use of a metallic stent to manage a benign colon condition was reviewed.

Strategies in the management of mid and distal rectal cancer with total mesorectal excision

In the last two decades, dramatic improvement in outcome has been made in the management of rectal cancer. This has been brought about mainly by advancements in surgical technique for radical resection. With the recognition of the importance of the circumferential margin and presence of spread in the lymphovascular tissues in the mesorectum, total mesorectal excision is now commonly recognized as the optimal surgical technique for cancer of the mid and distal rectum. Not only have local control and disease-specific survival improved with the practice of total mesorectal excision, but various bodily functions have also been preserved following surgery for rectal cancer. New issues have arisen with the practice of total mesorectal excision and the strategies for management of rectal cancer require re-evaluation. In this article, the rationale and the outcomes of total mesorectal excision are reviewed. Issues such as the high anastomotic leakage rate following sphincter-preserving surgery, the poor results of abdominoperineal resection, the role of adjuvant therapy and bowel function disturbances will be addressed. Lastly, the status of the laparoscopic approach to rectal cancer with the principle of total mesorectal excision are discussed.

Randomized clinical trial comparing loop ileostomy and loop transverse colostomy for faecal diversion following total mesorectal excision

BACKGROUND

The aim of this study was to compare loop ileostomy and loop transverse colostomy as the preferred mode of faecal diversion following low anterior resection with total mesorectal excision for rectal cancer.

METHODS

Patients who required proximal diversion after low anterior resection with total mesorectal excision were randomized to have either a loop ileostomy or a loop transverse colostomy. Postoperative morbidity, stoma-related problems and morbidity following closure were compared.

RESULTS

From April 1999 to November 2000, 42 patients had a loop ileostomy and 38 had a loop transverse colostomy constructed following low anterior resection. Postoperative intestinal obstruction and prolonged ileus occurred more commonly in patients with an ileostomy (P = 0.037). There was no difference in time to resumption of diet, length of hospital stay following stoma closure and incidence of stoma-related complications after discharge from hospital. A total of seven patients had intestinal obstruction from the time of stoma creation to stoma closure (six following ileostomy and one following colostomy; P = 0.01).

CONCLUSION

Intestinal obstruction and ileus are more common after loop ileostomy than loop colostomy. Loop transverse colostomy should be recommended as the preferred method of proximal faecal diversion.

Analysis of risk factors for local delivery of low- and intermediate-dose adenovirus gene transfer vectors to individuals with a spectrum of comorbid conditions

In this study we analyze the adverse events and abnormal laboratory parameters following local administration of low (<10(9) particle units) and intermediate (10(9)-10(11) particle units) single and repetitive doses (140 total) of E1(-)E3(-) adenovirus (Ad) gene transfer vectors administered to the respiratory epithelium, solid tumors, skin, myocardium, and skeletal muscle in eight gene transfer trials since April 1993. In the accompanying paper by Harvey et al., (Hum. Gene Ther. 2002; 13:15-63), we conclude that for the total group, no deaths were attributable to the Ad vectors per se, and the incidence of major adverse events likely caused by an Ad vector was 0.7%. The present study analyzes the trials as a group to evaluate risk factors for the adverse events, abnormal values among laboratory parameters, and known deaths. Ten putative risk factors were assessed, including "patient-related" (age, sex, comorbid index and pretherapy anti-Ad antibodies), "vector-related" (dose, route, transgene, and number of vector administrations), and "trial-related" (trial in which the individual was enrolled, and whether surgery was part of the trial). While assessment of each factor individually suggested several possible associations with adverse events, abnormal laboratory parameters, or deaths, multivariate analysis identified only age, comorbid index, and surgery (comorbid index for death; age and surgery for non-death adverse events) as variables significantly associated with increased risk for a major (severity scale 3-4 of 4) adverse event for individuals enrolled in these gene transfer trials. Importantly, multivariate analysis suggested that vector-related parameters, including dose, route, transgene, or number of vector administrations at the doses and routes evaluated in these studies, do not appear to be significant risk factors for a major adverse event. With the caveat that these are phase I, uncontrolled trials, we conclude that (1) there is no definitive risk factor that will clearly predict a major adverse outcome resulting from local administration of low and intermediate doses of Ad gene transfer vectors; and (2) major adverse events in these gene transfer trials are associated primarily with the study population and/or trial procedures, not the Ad vectors themselves. This assessment is consistent with the concept that local administration of low and intermediate doses of Ad gene transfer vectors appears to be well tolerated.

Safety of local delivery of low- and intermediate-dose adenovirus gene transfer vectors to individuals with a spectrum of morbid conditions

To help define the safety profile of the use of adenovirus (Ad) gene transfer vectors in humans, this report summarizes our experience since April 1993 of the local administration of E1(-)/E3(-) Ad vectors to humans using low (<10(9) particle units) or intermediate (10(9)-10(11) particle units) doses. Included in the study are 90 individuals and 12 controls, with diverse comorbid conditions, including cystic fibrosis, colon cancer metastatic to liver, severe coronary artery disease, and peripheral vascular disease, as well as normals. These individuals received 140 different administrations of vector, with up to seven administrations to a single individual. The vectors used include three different transgenes (human cystic fibrosis transmembrane conductance regulator cDNA, E. coli cytosine deaminase gene, and the human vascular endothelial growth factor 121 cDNA) administered by six different routes (nasal epithelium, bronchial epithelium, percutaneous to solid tumor, intradermal, epicardial injection of the myocardium, and skeletal muscle). The total population was followed for 130.4 patient-years. The study assesses adverse events, common laboratory tests, and long-term follow-up, including incidence of death or development of malignancy. The total group incidence of major adverse events linked to an Ad vector was 0.7%. There were no deaths attributable to the Ad vectors per se, and the incidence of malignancy was within that expected for the population. Overall, the observations are consistent with the concept that local administration of low and intermediate doses of Ad vectors appears to be well tolerated.

Impact of total mesorectal excision on the results of surgery of distal rectal cancer

BACKGROUND

This study reviewed the results of surgery for distal rectal cancer (tumours within 6 cm of the anal verge) following the introduction of total mesorectal excision for rectal cancer in one institution.

METHODS

Two hundred and five patients who had undergone surgical resection of rectal cancer within 6 cm of the anal verge were included. The demographic, operative and follow-up data were collected prospectively. Comparisons were made between patients who had different surgical procedures.

RESULTS

Abdominoperineal resection (APR) was performed in 27.8 per cent of patients, falling from 36.0 per cent in the first 3 years to 20.0 per cent in the last 3 years of the study. The overall operative mortality rate was 1.5 per cent and the morbidity rate 30.2 per cent. With a mean follow-up of 36 months, local recurrence occurred in 28 of the 185 patients who had curative resection. The 5-year actuarial local recurrence rates for double-stapled anastomosis, peranal coloanal anastomosis and APR were 11.2, 34.6 and 23.5 per cent respectively. The local recurrence rate was significantly lower for double-stapled low anterior resection than for the other types of operation. The overall 5-year survival rate in patients with low anterior resection and APR was 69.1 and 51.1 per cent respectively (P = 0.12).

CONCLUSION

With the practice of total mesorectal excision, APR was necessary in only 27.8 per cent of patients with rectal cancer within 6 cm of the anal verge. The local recurrence rate was much lower in patients with double-stapled low anterior resection than in those treated with APR or peranal anastomosis.

Clinical protocol. An open-label, phase I, single administration, dose-escalation study of ADGVPEDF.11D (ADPEDF) in neovascular age-related macular degeneration (AMD)

Age-Related Macular Degeneration (AMD) is, together with Diabetic Retinopathy, the most common cause of vision loss among adults in the U.S. and other developed countries. In the U.S., at least 1.7 million people have impaired vision due to AMD. Every year, more than 165,000 people contract AMD and 16,000 go blind from it, predominantly from a rapidly progressing form of the disease called "wet" AMD. Wet AMD is characterized by serious or hemorrhagic detachment of the retinal pigment epithelium and choroidal neovascularization. The macula has the highest concentration of photoreceptors facilitating central vision and permitting high-resolution visual acuity. The damage caused by the leakage and fibrovascular scarring in wet AMD leads to profound loss of central vision and severe loss of visual acuity (usually 20/200 or worse). People with wet AMD have several limitations, including inability to read, inability to recognize faces or drive, and the disease often leads to blindness. The onset of severe visual changes in wet AMD can occur suddenly. More than 400,000 Americans are currently affected by this form of the disease, and the incidence is rising rapidly with the aging of the population. Therefore, the serious consequences of this disease along with the limited treatment options and their effectiveness make this a very good candidate for a gene transfer treatment approach. The investigational agent, Ad(GV)PEDF.11D, is an E1-, partial E3-, E4- deleted replication-deficient, adenovirus serotype 5, gene transfer vector. The transgene in this vector is the cDNA for human pigment epithelium-derived factor (PEDF). PEDF is one of the most potent known antiangiogenic proteins found in humans. While Ad(GV)PEDF.11D is able to transduce many somatic cell types, the natural barrier to other tissues created by the retina limits the ability of Ad(GV)PEDF.11D to affect tissues other than in the eye. Intravitreal administration of Ad(GV)PEDF.11D provides a convenient means of delivering PEDF to the relevant cells within the eye likely to result in a more prolonged duration of effect versus administration of the PEDF protein alone. In three murine disease models (the laser-induced choroidal neovascularization model, the VEGF transgenic model, and the retinopathy of prematurity model) significant inhibition of neovascularization (up to 85%) was demonstrated with doses of Ad(GV)PEDF vectors ranging from 1 x 10(8) to 1 x 10(9) pu. In toxicology studies performed in Cynomolgus monkeys, a dose-related inflammatory response was observed. A dose of 1 x 10(8) pu caused no adverse effects, while the inflammatory response observed at 1 x 10(9) pu was minimal and fully reversible. The observed inflammatory response at doses of 1 x 10(10) and 5 x 10(10) pu were increasingly severe. The proposed clinical trial is an open-label, dose-escalation, phase I study to investigate the safety, tolerability and potential activity of intravitreal injection of Ad(GV)PEDF.11D in patients with wet AMD. Ad(GV)PEDF.11D will be injected once via intravitreal injection into the eye with the most advanced AMD based on visual acuity. Subjects will be age 50 or over and have severe wet AMD in at least one eye defined by a best-corrected vision of 20/200 or worse. The primary objectives of this investigation are: (1) to assess the safety, tolerability and feasibility of intravitreal injection of Ad(GV)PEDF.11D in patients with severe, neovascular AMD, (2) to identify the maximum tolerated dose (MTD) of Ad(GV)PEDF.11D, and (3) to get some indication of potential activity of Ad(GV)PEDF.11D.

Emergency surgery for colonic diverticulitis: differences between right-sided and left-sided lesions

BACKGROUND AND AIMS

Right-sided diverticulitis is rare in Western societies but is not uncommon in Asian countries. Many of the patients are operated with the presumptive diagnosis of appendicitis. This study compared the results of emergency surgery for patients with right-sided and left-sided diverticulitis.

PATIENTS AND METHODS

Demographic data, type of operation, and surgical outcome were recorded in 60 patients who had undergone emergency surgery for colonic diverticulitis (37 right-sided, 23 left-sided).

RESULTS

Patients with right-sided disease were significantly younger (mean age 41.9 vs. 74.2), and there was a tendency to male predominance (78.4% vs. 56.5%). All patients with right-sided disease had localized peritonitis while 74% of patients with perforated left-sided diverticulitis had generalized faecal or purulent peritonitis. Mortality rates for right-sided disease and left-sided disease were 0% and 13%, respectively, and morbidity was 14.2% and 61%, respectively. Longer hospital stay was also found in patients with left-sided diverticulitis.

CONCLUSIONS

There are major differences in the demographics, presentation, type of operation and outcome of patients who had emergency surgery for colonic diverticulitis, with emergency operation for left-sided diverticulitis being associated with higher mortality and morbidity.

Radiation recall with oxaliplatin: report of a case and a review of the literature

Oxaliplatin is a new platinum derivative that has significant activity in patients with metastatic colorectal carcinoma. Some of these patients may have been previously treated with radiotherapy. The interaction of radiotherapy with oxaliplatin needs to be further studied. We report a patient with advanced colonic carcinoma who was treated with concomitant chemoirradiation with oxaliplatin and developed a peculiar dermnatitis in the irradiated field after being exposed to subsequent chemotherapy with oxaliplatin.

Emergency surgery for obstructing colorectal cancers: a comparison between right-sided and left-sided lesions

BACKGROUND

Fifteen to twenty percent of patients with primary colorectal cancers present with intestinal obstruction. Traditionally, different approaches have been used in the management of right-sided and left-sided colonic obstruction. Recently, single-stage resection with primary anastomosis in left colonic obstruction has been shown to have good results. The objective of this study was to compare the operative results of patients who had emergency operations for right-sided and left-sided obstructions from primary colorectal cancers.

STUDY DESIGN

This is a retrospective study including 243 patients who underwent emergency operations for obstructing colorectal cancers from 1989 to 1997. Primary resection of the tumor-bearing segment followed by primary anastomosis was attempted when the conditions were feasible. The operative results of patients with right-sided tumors were compared with those of patients with left-sided tumors.

RESULTS

One hundred seven patients had obstruction at or proximal to the splenic flexure (right-sided lesions), and 136 had lesions distal to the splenic flexure (left-sided lesions). The primary resection rate was 91.8%. Of the 223 patients with primary resection, primary anastomosis was possible in 197 patients. Among the 101 primary anastomoses in patients with left-sided obstruction, segmental resection with on-table lavage was performed in 75 patients and subtotal colectomy was performed in 26. The overall operative mortality rate was 9.4%, although that of the patients with primary resection and anastomosis was 8.1%. The anastomotic leakage rate for those with primary resection and anastomosis was 6.1%. There were no differences in the mortality or leakage rates between patients with right-sided and left-sided lesions (mortality: 7.3% versus 8.9%, p = 0.79; leakage: 5.2% versus 6.9%, p = 0.77). Colocolonic anastomosis did not show a significant difference in leakage rate when compared with ileocolonic anastomosis (6.1% versus 6.0%, p = 1.0).

CONCLUSIONS

This study showed that primary resection and anastomosis for left-sided malignant obstruction, either by segmental resection with on-table lavage or subtotal colectomy, was not more hazardous than primary anastomosis for right-sided obstruction. The single-stage procedure should be the objective for the treatment of patients with obstructing colorectal cancers, except when patients are hemodynamically unstable during surgery or when the condition of the bowel is not optimal for primary anastomosis.

Self-expanding metallic stent in the treatment of colonic obstruction caused by advanced malignancies

INTRODUCTION

The treatment of malignant obstruction of the left colon or rectum usually requires emergency surgery on poor-risk patients, and the creation of a stoma is usually inevitable. With the use of self-expanding metallic stents, the prompt relief of large-bowel obstruction without surgery has become possible. This report describes our results in the use of self-expanding metallic stents in the treatment of left-sided colonic obstruction resulting from advanced malignancies.

METHODS

From November 1997 to March 1999, insertion of self-expanding metallic stents was attempted in 24 patients with acute left-sided colonic obstruction caused by primary or recurrent malignancies. All the procedures were performed by colorectal surgeons. The guidewire was inserted through the channel of the endoscope, and its position was confirmed with fluoroscopy. Uncovered Wallstent esophageal endoprostheses were used in all except the first case. The insertion and deployment of the stents were under both endoscopic and fluoroscopic guidance.

RESULTS

There were 24 patients (15 males) with a mean age of 63.6 (range, 36-98) years. Thirteen patients had primary colorectal cancer and 11 had recurrent cancers (colorectal cancer, 5; gastric cancer, 5; other, 1). In the treatment of primary colorectal cancer, seven procedures were palliative, and no subsequent surgery was planned because of extensive liver metastasis or poor medical risk. The other six patients underwent elective resection after mechanical bowel preparation. There was no mortality related to the procedure. Stenting was successful in the relief of obstruction in 23 patients. Perforation of the colon occurred in one patient, and an emergency Hartmann's operation was performed. Migration of the stents occurred in three patients. Only 3 of the 18 patients in the palliation group required the subsequent creation of stomas.

CONCLUSION

The use of the self-expanding metallic stents can achieve rapid and effective nonsurgical means to relieve left-sided colonic obstruction. It provides good palliation for unresectable advanced tumors that cause colonic obstruction. It may also have a role in the temporary relief of obstruction so that subsequent colonic resection can be performed under elective conditions.

Resection of local recurrence of rectal cancer: results

Locally recurrent rectal cancer is a difficult clinical problem, and surgical resection can be done only in selected patients. The aims of this study were to evaluate the results of resecting the local recurrence of rectal cancer and to analyze factors that might predict curative re-resection and those that affect survival. Forty-seven patients who underwent resection for locally recurrent rectal cancer formed the basis of the study. Twenty-four were curative in nature, and the others were palliative. There was no operative mortality, and the complication rate was 38%. The median survival of the whole group was 16.5 months. The ability to perform curative resection was found to be the only independent factor associated with improved survival. Female gender is a significant factor associated with curative resection of local recurrence. In patients with curative reresection, local control is up to 87%. It was concluded that resection of local recurrent rectal cancer can achieve good local control and can improve survival in selected patients. The ability to perform curative resection is associated with survival benefit, and female gender is associated with the increased possibility of carrying out curative resection.

Risk factors for anastomotic leakage after low anterior resection with total mesorectal excision

BACKGROUND

This study aims to analyze the risk factors for anastomotic leakage after low anterior resection with the technique of total mesorectal excision (TME).

METHODS

From September 1993 to November 1998, 196 patients with rectal cancer from 3 to 12 cm from the anal verge were treated with low anterior resection with TME. The data were entered in a prospective manner, and the factors that might affect anastomotic leakage were analyzed.

RESULTS

The mean level of anastomosis was 3.6 cm from the anal verge (range 1 to 5 cm). The leakage rate was 10.2%. Female gender (P = 0.01; 95% confidence interval [CI] 1.3 to 14.3; odds ratio 4.3) and presence of a diversion stoma (P = 0.01; 95% CI 1.4 to 14.2; odds ratio 4.5) were independent significant factors for lower anastomotic leakage. The absence of a stoma was associated with significantly increased leakage in male (P = 0.001) but not in female (P = 0.51) patients.

CONCLUSIONS

With low anastomosis after low anterior resection with TME, diversion stoma construction should be performed routinely in men. In women, the need for diversion can be more selective.

Total pelvic exenteration for locally advanced rectal cancer

BACKGROUND

Since its first description in 1948, total pelvic exenteration has been a surgical option for the treatment of locally advanced rectal cancer in selected patients. During these 50 years, it has remained a formidable procedure with high mortality and substantial morbidity. This report describes the results of total pelvic exenteration for rectal cancer in terms of post-operative mortality, morbidity, and longterm survival in patients with locally advanced primary and recurrent rectal cancer.

STUDY DESIGN

A study of the patient records revealed that 24 patients underwent total pelvic exenteration as the treatment for locally advanced primary or recurrent cancer of the rectum from 1983 to 1998. The charts of the patients were reviewed, and morbidity and mortality were documented. The survival of the patients was also analyzed.

RESULTS

Fifteen patients had primary tumor and 9 had locally recurrent cancer. The mean age was 62 years old. There were no postoperative deaths, and the complication rate was 54%. In the treatment of primary tumor, bowel continuity was possible in 60% of the patients. Previous radiation or operation for recurrent disease was not associated with increased morbidity. The overall 5-year survival was 44%. The 5-year survival of patients with primary cancer was 64% and was significantly better than the rate for those with recurrent disease. Only one patient with recurrent disease survived more than 24 months.

CONCLUSIONS

Total pelvic exenteration now can be performed with low mortality rates, but the morbidity remains high. In the treatment of primary rectal cancer, good survival (64%) can be achieved, but results are dismal for the treatment of recurrent disease. We suggest better selection of patients for this procedure, especially as a treatment for recurrent rectal cancer.

Inflammatory cecal masses in patients presenting with appendicitis

An unexpected inflammatory cecal mass of uncertain etiology encountered during surgery for presumed appendicitis poses a dilemma to the surgeon when deciding the appropriate operative management. A retrospective study was performed to review the pathology and surgical management of this condition. Among 3224 patients who had emergency surgery for a diagnosis of acute appendicitis between January 1990 and December 1997, a group of 52 patients (1.6%) underwent either ileocecal resection or right hemicolectomy for an inflammatory cecal mass of uncertain etiology. The final pathologic diagnosis was cecal diverticulitis in 26 patients (50%), appendiceal phlegmon or abscess in 21 patients (40%), cecal carcinoma in 3 patients (6%), tuberculosis in 1 patient (2%) and schistosomiasis in another patient (2%). Altogether 34 patients underwent ileocecal resection, and 18 patients underwent right hemicolectomy, including the 3 patients with cecal carcinoma. Ileocecal resection was associated with a shorter mean operative time (144 vs. 201 minutes; p < 0.001), a lower morbidity rate (3% vs. 22%; p = 0.043), and a shortened mean postoperative hospital stay (6.8 vs. 11.2 days; p = 0. 011) than right hemicolectomy. There was no mortality in either group. In conclusion, most inflammatory cecal masses are due to benign pathologies and could be managed safely and sufficiently with ileocecal resection. Careful intraoperative assessment including examination of the resected specimen is essential to exclude malignancy, which would require right hemicolectomy.

Prospective evaluation of selective defunctioning stoma for low anterior resection with total mesorectal excision

Low anterior resection with total mesorectal excision for rectal carcinoma is associated with a high anastomotic leakage rate, and the effectiveness of a defunctioning stoma in preventing anastomotic leakage remains controversial. In this study a policy of selective defunctioning stoma for stapled colorectal anastomosis after low anterior resection with total mesorectal excision in 148 consecutive patients was evaluated prospectively. A defunctioning stoma was performed in 61 patients (41%) considered at high risk of anastomotic leakage. Clinical leakage occurred in 2 patients (3.3%) with a stoma and 11 patients (12.6%) without a stoma (p = 0.047). Among those without a stoma, the leakage rate among male patients (20.9%) was significantly higher than that for female patients (4. 5%) (p = 0.022). Leakage subsided with conservative treatment in the two patients with a stoma, but seven patients without a stoma developed peritonitis requiring laparotomy. No deaths resulted from leakage, and there was one hospital death (0.6%) in the whole group. Median hospital stay was similar with and without a stoma (13.0 vs. 12.0 days) (p = 0.290). Closure of the stoma was associated with no mortality, a morbidity rate of 8.7%, and a median hospital stay of 6. 0 days. In conclusion, a defunctioning stoma is effective in preventing clinical anastomotic leakage after low anterior resection with total mesorectal excision. The relatively high incidence of leakage in the low risk group indicates the difficulty of predicting anastomotic leakage and hence the need for more liberal use of a defunctioning stoma especially in male patients.

Triple rubber band ligation for hemorrhoids: prospective, randomized trial of use of local anesthetic injection

PURPOSE

Rubber band ligation is a common office procedure for hemorrhoids. Triple rubber band ligation in a single session has been shown to be a safe and economical way of treating hemorrhoids. However, postligation discomfort after triple rubber band ligation is not uncommon. The aim of this study was to evaluate the effectiveness of local anesthetic injection to the banded hemorrhoidal tissue in reducing postligation discomfort.

METHODS

Patients attending an outpatient clinic for symptomatic hemorrhoids suitable for triple rubber band ligation were randomly assigned to two groups. In the treatment group rubber band ligation was performed at three columns of hemorrhoids, and 1 to 2 ml of 2 percent lignocaine was injected into the banded hemorrhoidal tissue. In the control group triple rubber band ligation was performed in a similar manner, but local anesthetic was not given. Patients were followed up by telephone at the second week and in the clinic after six weeks.

RESULTS

From April to August 1996, 101 patients entered the trial and were treated with triple rubber band ligation. Sixty-two patients were randomly assigned to the local anesthetic injection group and 39 to the control group. Overall good to excellent results occurred in 89 percent of patients, and there was no difference between the two groups. Postligation pain occurred in 26 and 20 percent of patients in the treatment and control groups, respectively (P > 0.05). Postligation tenesmus occurred in 32 and 41 percent of patients in the treatment and control groups, respectively (P > 0.05). No patients suffered from septic complications or bleeding that required transfusion.

CONCLUSION

Triple rubber band ligation in a single session is a safe, economical, and effective way of treating symptomatic hemorrhoids. Postligation pain and tenesmus occurred in 24 and 37 percent, respectively. Discomfort was usually tolerable. Local anesthetic injection to the banded hemorrhoidal tissue did not help to reduce postligation discomfort.

Emergency resection and primary anastomosis for left-sided obstructing colorectal carcinoma in the elderly

BACKGROUND

Emergency colorectal surgery in the elderly has been associated with a high mortality rate. Although the current trend for the management of obstructing left-sided colorectal carcinoma favours primary resection and anastomosis, the safety and benefits of this approach in the elderly have not been studied.

METHODS

Some 57 elderly (aged more than 70 years) and 59 younger patients underwent emergency resection of an acutely obstructing left-sided colorectal carcinoma. Postoperative results in the two groups were compared.

RESULTS

The primary resection rate was 95 per cent in the elderly and 89 per cent in younger patients (P = 0.70), with a primary anastomosis rate of 84 per cent and 78 per cent respectively (P = 0.64). Elderly patients had a significantly higher incidence of premorbid risk factors and postoperative cardiorespiratory complications but no increase in surgical complications. Anastomotic leaks occurred in 6 per cent of the elderly and 4 per cent of younger patients (P = 0.65), and the hospital mortality rate was 9 and 5 per cent respectively (P = 0.48).

CONCLUSION

Emergency resection and primary anastomosis for left-sided obstructing colorectal carcinoma can be performed with favourable outcome in the elderly and should be the treatment of choice in most elderly patients.

Identification of lactams as in vitro metabolites of piperidine-type phenothiazine antipsychotic drugs

The metabolism of the piperidine-type phenothiazine antipsychotic agents thioridazine, mesoridazine and sulforidazine was studied in vitro with 10,000 g liver supernatants obtained from rats and dogs. After incubations at 37 degrees C for different time intervals, the incubates were extracted with dichloromethane and the isolated compounds analyzed by HPLC, direct probe MS and on-line HPLC-MS. Five lactam metabolites of these three drugs were unequivocally identified in the rat in vitro system, but none was found in dog preparations; at least one lactam metabolite was identified for each drug in the rat. The lactams of thioridazine and thioridazine ring sulfoxide were characterized as metabolites of thioridazine for the first time in any system. The other three lactam metabolites, namely the lactams of mesoridazine, sulforidazine and mesoridazine ring sulfoxide, were found in vitro for the first time, although they have been previously reported as in vivo metabolites of these drugs. The results indicate that rat would be a more suitable animal model than dog for further studies on the formation of lactam metabolites of these drugs.

Acute diverticulitis of the right colon

BACKGROUND

Acute diverticulitis of the right colon is a rare condition with a higher incidence in Oriental populations than in Occidental populations.

PATIENTS AND METHODS

A retrospective review was conducted between 1982 and 1993 on 22 surgically treated Chinese patients (14 men, 8 women; mean age 47 years) with documented right colon diverticulitis.

RESULTS

Most patients presented with right lower quadrant pain and local peritoneal signs. Acute appendicitis was the preoperative diagnosis in 82% (18/22) of the patients. Only one diagnosis subsequently proved correct. The pathology was easily recognized in 4 patients during surgery, while examination of the resected specimen confirmed the intraoperative suspicion in 13 patients. The right colon was resected and an ileocolonic anastomosis performed in 21 patients; the remaining patient underwent diverticulectomy and drainage of a pericolic abscess. There was no postoperative mortality, and 4 patients developed wound infection.

CONCLUSIONS

Our results showed that acute diverticulitis of the right colon was encountered once in 180 cases of acute appendicitis. Local resection or colectomy with primary anastomosis without bowel preparation is the procedure of choice.

Bleeding angiodysplasia of the gastrointestinal tract

Bleeding angiodysplasia of the gastrointestinal tract poses frustrating challenges to clinicians because these minute vascular lesions are difficult to diagnose pre-operatively and to locate intra-operatively. During the past 12 years, 24 patients were treated for histopathologically confirmed bleeding angiodysplasia of the gastrointestinal tract. Pre-operative investigations and intra-operative localization followed a fixed protocol for patients with gastrointestinal bleeding of obscure origin. The median follow-up of these 24 patients was 51 months and the results of treatment for 22 patients were excellent. Two patients had recurrent bleeding but investigations failed to determine the bleeding source.

Obscure bleeding in the gastrointestinal tract originating in the small intestine

In the past 12 years, we operated upon 49 patients with bleeding lesions of the small intestine. After endoscopic examination and barium studies of the upper and lower gastrointestinal tract excluded esophagogastroduodenal and lesions of the colon and rectum, preoperative examinations consisted of technetium-99m pertechnetate scan, technetium-99m labeled erythrocyte scan, barium studies of the small intestine and selective visceral angiogram. In one patient, diagnostic laparotomy had to be done before any procedure because of severe bleeding and angiosarcoma of the ileum. The results of gross examination at operation revealed bleeding lesions in 40 patients. Special intraoperative localization procedures consisting of methylene blue injection through superselectively prepositioned angiographic catheter was done on eight patients, and intraoperative enteroscopy was done on 17 patients. These two procedures were complementary, having their own indications and limitations. Our regimen of preoperative and intraoperative localization procedures was effective in the management of bleeding small intestinal lesions.

Operative choledochoscopy in patients with acute cholangitis: a prospective, randomized study

A prospective, randomized evaluation of operative choledochoscopy was carried out during emergency surgery in patients with acute cholangitis or acute suppurative cholangitis when conservative management had failed. After common bile duct exploration, 79 patients were randomized to have choledochoscopy and 78 patients to the control group. Laboratory and clinical parameters showed that choledochoscopy did not increase the incidence of septicaemia, acute pancreatitis, persistent cholangitis, postoperative wound sepsis, intraperitoneal sepsis and hospital mortality. The incidence of retained common bile duct stones detected by T tube cholangiography performed in the second postoperative week was significantly reduced (P less than 0.01) after choledochoscopy. Choledochoscopy detected stones missed by conventional common bile duct exploration in ten patients. It is concluded that choledochoscopy is a safe and effective technique in patients with acute cholangitis and acute suppurative cholangitis.

Systemic antibiotic regimens for acute cholecystitis treated by early cholecystectomy

A total of 203 patients were randomized into a prospective trial to compare short (SC) versus long courses (LC) of systemic antibiotic for acute cholecystitis treated by early cholecystectomy. The initial pre-operative management was the same and all patients received 2 g of cefamandole intravenously just before operation. Two further doses of cefamandole 500 mg were given 6 and 12 h later for patients on SC while the antibiotic was continued at 500 mg at 6 h intervals for 7 days for patients on LC. Seven patients developed wound infection on SC compared with five patients with wound infection and an additional patient with a subphrenic abscess on LC (P greater than 0.05). Thrombophlebitis related to intravenous antibiotic injections was more common in patients on LC (P less than 0.05). Also, patients on LC had to stay statistically longer in hospital in order to complete the course of antibiotic (P less than 0.05). We therefore recommend a SC to be used, as it is more cost-effective and causes fewer complications.

Leucocyte count and neutrophil percentage in appendicectomy for suspected appendicitis

The total leucocyte count (TLC) and neutrophil percentage (NP) were studied prospectively in 1032 patients who underwent appendicectomy for suspected acute appendicitis. On histopathological study of the resected appendices, 97 patients had normal appendices, and 935 patients had acutely inflamed, gangrenous or perforated appendicitis. Statistically more patients with appendicitis had either raised TLC or raised NP compared with patients with normal appendices (P less than 0.001), and also compared with 357 patients who were admitted with right lower quadrant abdominal pain but were not subjected to operation (P less than 0.001). The sensitivity and specificity of raised TLC in diagnosing appendicitis for patients who underwent appendicectomy were 81.4% and 77.3%, respectively. Sensitivity increased when either raised TLC or raised NP were used, but specificity decreased. In contrast, sensitivity decreased when both raised TLC and raised NP were used together, but specificity increased. Raised TLC, preferably combined with raised NP, is a useful diagnostic aid in acute appendicitis. The TLC and NP, however, should only be interpreted in the light of physical findings in patients with suspected appendicitis because these blood tests have false positive and false negative results.

Repeat selective visceral angiography in patients with gastrointestinal bleeding of obscure origin

In the past 9 years, we have operated on 56 patients with gastrointestinal bleeding of obscure origin. Selective visceral angiography demonstrated the bleeding lesions in 24 of the 30 patients who underwent this investigation. Six of these 24 patients, however, had a negative angiogram initially and the lesions were only demonstrated on a repeat angiogram. The negative initial angiograms were due to: (1) slow bleeding from lesions in two patients; (2) a small bleeding tumour that caused only intermittent jejunojejunal intussusception in one patient; (3) technical fault in one patient; and (4) spasm of the bleeding vascular lesions and their feeding arteries in two patients. We advocate repeat angiography the following day in all patients in whom profuse bleeding continues, and during the next intestinal bleeding in those whose bleeding stops after the initial negative angiography. In patients who have repeated episodes of massive bleeding, and in whom full investigations fail to reveal the bleeding source, repeat angiography carried out 4 weeks after the bleeding has stopped can sometimes demonstrate the vascular lesions.

Predictive value of surveillance skin and hub cultures in central venous catheters sepsis

In a prospective study of septic complications of central venous catheters used for total parenteral nutrition, daily surveillance catheter hub cultures and twice weekly skin cultures at the catheter entry site were evaluated for their predictive value for catheter sepsis, i.e. bacteraemia with an identical species as that recovered from the catheter tip, or catheters which grew greater than or equal to 15 cfus by a semiquantitative method and/or greater than or equal to 10(3) cfus by a quantitative method. Of 142 catheters studied, 29 were identified to have catheter sepsis. For these the sensitivity of the surveillance hub culture was 34.5% and the sensitivity of the skin culture was 37.9%. When either the hub or the skin culture result was considered as an indication of catheter sepsis, the sensitivity increased to 79.3%. The positive and negative predictive value of the combined result was 44.2% and 93.3% respectively. This study suggests that simultaneous hub and skin cultures are required for a satisfactory surveillance.

Prophylactic antibiotics in elective colorectal surgery

A randomized prospective study was conducted on 194 patients who underwent elective colorectal surgery for carcinoma. All patients received the same mechanical bowel preparation. In addition, patients in group A received oral neomycin and erythromycin base; patients in group B received systemic metronidazole and gentamicin, while patients in group C received both oral and systemic antibiotics. Postoperative septic complications related to colorectal surgery occurred in 27.4 per cent, 11.9 per cent and 12.3 per cent respectively in groups A, B and C (chi 2 = 7; P less than 0.05). The incidence of sepsis in groups B and C was almost identical. Patients who received oral antibiotics alone (group A) had significantly higher risks of postoperative sepsis when compared with patients in either group B or group C (P less than 0.05). As there is no additional advantage of combining oral and systemic antibiotics, we recommend systemic metronidazole and gentamicin to be used with mechanical bowel preparation in elective colorectal surgery.