Amputation surgery associated with shortened survival in patients with localized extremity bone sarcoma

Background

This study assesses survival rates among patients with localized extremity bone sarcoma who have undergone amputation, pinpointing subpopulations that are disproportionately affected by amputation-related survival disparities.

Methods

Examination of data was conducted using the Surveillance, Epidemiology, and End Results (SEER) program, analyzing records of 3765 patients diagnosed with localized extremity bone sarcoma between 2000 and 2019. Of these, 857 received amputations (Amputation cohort), and 2908 underwent limb-sparing surgeries. Propensity score matching, considering demographic and clinical features, was utilized to ensure a fair comparison.

Results

Following propensity score matching, the study focused on 1714 cases. The Amputation cohort was observed to have significantly poorer survival rates (Cancer-Specific Survival [CSS]: Hazard Ratio [HR] = 1.28, 95% Confidence Interval [CI]: 1.05-1.55; Overall Survival [OS]: HR = 1.37, 95% CI: 1.15-1.63). Subsequent subgroup analysis indicated that individuals with tumors exceeding 8 cm in size or those located in the lower limbs were notably at a higher risk of shortened survival (for tumors >8 cm - CSS: HR = 1.32, 95% CI: 1.02-1.71; OS: HR = 1.39, 95% CI: 1.09-1.76; for lower limb tumors - CSS: HR = 1.25, 95% CI: 1.01-1.54; OS: HR = 1.33, 95% CI: 1.11-1.61).

Conclusions

Our findings demonstrate that patients diagnosed with localized extremity bone sarcoma undergoing amputation exhibit lower survival rates, especially in cases involving tumors of greater size or those situated in the lower limbs. In patient groups where amputation is inevitable, careful follow-up is required after surgical intervention.

Macrophage-derived extracellular vesicles trigger non-canonical pyroptosis in chondrocytes leading to cartilage catabolism in osteoarthritis

OBJECTIVES

The severity of osteoarthritis and cartilage degeneration are highly correlated with the development of synovitis, which is mediated by the activity of inflammatory macrophages. A better understanding of intercellular communication between inflammatory macrophages and chondrocytes should aid in the discovery of novel therapeutic targets. Here, we explored the pathological role of inflammatory macrophage extracellular vesicles in cartilage degeneration.

METHODS

Macrophages were stimulated by treatment with bacterial lipopolysaccharides to mimic the state of inflammatory macrophages and the resulting extracellular vesicles were harvested for chondrocyte stimulation in vitro and intraarticular injection in a mouse model. The stimulated chondrocytes were further subjected to RNA-seq analysis and other functional assays. The action of caspase-11 was disrupted in vitro using a specific siRNA or wedelolactone, and in experimental OA-murine models by the intraarticular injection of wedelolactone.

RESULTS

Stimulated chondrocytes exhibited a significant elevation in the expression of chondrocyte catabolic factors. Consistent with these results, RNA-seq analyses of stimulated chondrocytes indicated that upregulated genes are mainly categorized into apoptotic process and TNF-signaling pathway which suggests the induction of apoptotic process. Moreover, these chondrocytes exhibited a significant elevation in the expression of pyroptosis-related molecules that were correlated with the expression of chondrocyte catabolic factors. The disruption of caspase-11 significantly alleviated pyroptotic and catabolic processes in stimulated chondrocytes and the pathological changes in collagenase-and joint instability-induced OA models.

CONCLUSIONS

Our results provide a new insight into the pathological mechanisms of OA and suggest that non-canonical pyroptosis in chondrocytes represents an attractive therapeutic target for future treatment.

Heterogeneity of management practices surrounding operable gallbladder cancer - results of the OMEGA-S international HPB surgical survey

BACKGROUND

Gallbladder cancer (GBC) is an aggressive, uncommon malignancy, with variation in operative approaches adopted across centres and few large-scale studies to guide practice. We aimed to identify the extent of heterogeneity in GBC internationally to better inform the need for future multicentre studies.

METHODS

A 34-question online survey was disseminated to members of the European-African Hepatopancreatobiliary Association (EAHPBA), American Hepatopancreatobiliary Association (AHPBA) and Asia-Pacific Hepatopancreatobiliary Association (A-PHPBA) regarding practices around diagnostic workup, operative approach, utilization of neoadjuvant and adjuvant therapies and surveillance strategies.

RESULTS

Two hundred and three surgeons responded from 51 countries. High liver resection volume units (>50 resections/year) organised HPB multidisciplinary team discussion of GBCs more commonly than those with low volumes (p < 0.0001). Management practices exhibited areas of heterogeneity, particularly around operative extent. Contrary to consensus guidelines, anatomical liver resections were favoured over non-anatomical resections for T3 tumours and above, lymphadenectomy extent was lower than recommended, and a minority of respondents still routinely excised the common bile duct or port sites.

CONCLUSION

Our findings suggest some similarities in the management of GBC internationally, but also specific areas of practice which differed from published guidelines. Transcontinental collaborative studies on GBC are necessary to establish evidence-based practice to minimise variation and optimise outcomes.

Low-Grade Inflammation in the Pathogenesis of Osteoarthritis: Cellular and Molecular Mechanisms and Strategies for Future Therapeutic Intervention

Osteoarthritis (OA) is a musculoskeletal disease characterized by cartilage degeneration and stiffness, with chronic pain in the affected joint. It has been proposed that OA progression is associated with the development of low-grade inflammation (LGI) in the joint. In support of this principle, LGI is now recognized as the major contributor to the pathogenesis of obesity, aging, and metabolic syndromes, which have been documented as among the most significant risk factors for developing OA. These discoveries have led to a new definition of the disease, and OA has recently been recognized as a low-grade inflammatory disease of the joint. Damage-associated molecular patterns (DAMPs)/alarmin molecules, the major cellular components that facilitate the interplay between cells in the cartilage and synovium, activate various molecular pathways involved in the initiation and maintenance of LGI in the joint, which, in turn, drives OA progression. A better understanding of the pathological mechanisms initiated by LGI in the joint represents a decisive step toward discovering therapeutic strategies for the treatment of OA. Recent findings and discoveries regarding the involvement of LGI mediated by DAMPs in OA pathogenesis are discussed. Modulating communication between cells in the joint to decrease inflammation represents an attractive approach for the treatment of OA.

Determination of optimal concentration of vitamin E in polyethylene liners for producing minimal biological response to prosthetic wear debris

The introduction of vitamin E-blended ultra-high molecular weight polyethylene (VE-UHMWPE) for use in prosthetic components of hip implants has resulted in the production of implants that have excellent mechanical properties and substantially less adverse cellular responses. Given the importance of a biological response to wear in the survival of a prosthesis, we generated wear debris from UHMWPE that had been prepared with different concentrations of vitamin E of 0.1, 0.3, 0.5, and 1% and evaluated their biological reaction in vitro and in vivo. All types of VE-UHMWPE debris promoted a significantly lower expression of Tnf-α in murine peritoneal macrophages than that induced by conventional UHMWPE debris. However, levels of Tnf-α were not significantly different among the macrophages that were stimulated with VE-UHMWPE wear at the concentrations tested. The ability of wear debris to induce inflammatory osteolysis was assessed in a mouse calvarial osteolysis model. The expressions of Tnf-α, Il-6, and Rankl in granulomatous tissue formed around the wear debris were significantly reduced in mice that had been implanted with 0.3%VE-UHMWPE debris as compared to the corresponding values for mice that had been implanted with UHMWPE debris. Consistent with this finding, 0.3%VE-UHMWPE debris showed the lowest osteolytic activity, as evidenced by the reduced bone resorption area, the degree of infiltration of inflammatory cells and the TRAP staining area. Our results suggested that a 0.3% vitamin E concentration is the most appropriate concentration for use in prosthetic components with a reduced adverse cellular response for prolonging the life-span of the implant.

Rheumatoid Arthritis is a Risk Factor for Refracture in Patients with Fragility Fractures

OBJECTIVES

To determine whether patients with rheumatoid arthritis (RA) who have had fragility fractures are at an increased risk of refractures.

METHODS

Patients with fragility fractures who were treated surgically at ten hospitals from 2008 to 2017 and who underwent follow-up for more than 24 months were either categorized into a group comprising patients with RA or a group comprising patients without RA (controls). The groups were matched 1:1 by propensity score matching. Accordingly, 240 matched participants were included in this study. The primary outcome was the refracture rate in patients with RA as compared to in the controls. Multivariable analyses were also conducted on patients with RA to evaluate the odds ratios (ORs) for the refracture rates.

RESULTS

Patients with RA were significantly associated with increased rates of refractures during the first 24 months (OR: 2.714, 95% confidence interval [95% CI]: 1.015-7.255; P = 0.040). Multivariable analyses revealed a significant association between increased refracture rates and long-term RA (OR: 6.308, 95% CI: 1.195-33.292; P=0.030).

CONCLUSIONS

Patients with RA who have experienced fragility fractures are at an increased risk of refractures. Long-term RA is a substantial risk factor for refractures.

Cardiotrophin Like Cytokine Factor 1 (CLCF1) alleviates bone loss in osteoporosis mouse models by suppressing osteoclast differentiation through activating interferon signaling and repressing the nuclear factor-κB signaling pathway

A growing body of evidence suggests that immune factors that regulate osteoclast differentiation and bone resorption might be promising therapeutic agents for the treatment of osteoporosis. The expression of CLCF1, an immune cell-derived molecule, has been reported to be reduced in patients with postmenopausal osteoporosis. This suggests that it may be involved in bone remodeling. Thus, we explored the functional role of CLCF1 in osteoclastogenesis and bone loss associated with osteoporosis. Surprisingly, the administration of recombinant CLCF1 repressed excessive bone loss in ovariectomized mice and prevented RANKL-induced bone loss in calvarial mouse model. Likewise, the addition of recombinant CLCF1 to RANKL-stimulated monocytes resulted in a significant suppression in the number of differentiated osteoclasts with small resorption areas being observed on dentine slices in vitro. At the same dosage, CLCF1 did not exhibit any detectable negative effects on the differentiation of osteoblasts. Mechanistically, the inhibition of osteoclast differentiation by the CLCF1 treatment appears to be related to the activation of interferon signaling (IFN) and the suppression of the NF-κB signaling pathway. Interestingly, the expression of the main components of IFN-signaling namely, STAT1 and IRF1, was detected in macrophages as early as 1 h after stimulation with CLCF1. Consistent with these results, the blockade of STAT1 in macrophages abolished the inhibitory effect of CLCF1 on osteoclast differentiation in vitro. These collective findings point to a novel immunoregulatory function of CLCF1 in bone remodeling and highlight it as a potentially useful therapeutic agent for the treatment of osteoporosis.

Targeting thymidine phosphorylase as a potential therapy for bone loss associated with periprosthetic osteolysis

Macrophages are generally thought to play a key role in the pathogenesis of aseptic loosening through initiating periprosthetic inflammation and pathological bone resorption. The aim of this study was to identify macrophage-derived factors that promote osteoclast differentiation and periprosthetic bone destruction. To achieve this, we examined the effects of 12 macrophage-derived factors that were identified by RNA-seq analysis of stimulated macrophages on osteoclast differentiation. Surprisingly, thymidine phosphorylase (TYMP) was found to trigger significant number of osteoclasts that exhibited resorbing activities on dentine slices. Functionally, TYMP knockdown reduced the number of osteoclasts in macrophages that had been stimulated with polyethylene debris. TYMP were detected in serum and synovial tissues of patients that had been diagnosed with aseptic loosening. Moreover, the administration of TYMP onto calvariae of mice induced pathological bone resorption that was accompanied by an excessive infiltration of inflammatory cells and osteoclasts. The RNA-seq for TYMP-induced-osteoclasts was then performed in an effort to understand action mode of TYMP. TYMP stimulation appeared to activate the tyrosine kinase FYN signaling associated with osteoclast formation. Oral administration of saracatinib, a FYN kinase inhibitor, significantly suppressed formation of bone osteolytic lesions in a polyethylene debris-induced osteolysis model. Our findings highlight a novel molecular target for therapeutic intervention in periprosthetic osteolysis.

Flightless I is a catabolic factor of chondrocytes that promotes hypertrophy and cartilage degeneration in osteoarthritis

Synovial macrophages that are activated by cartilage fragments initiate synovitis, a condition that promotes hypertrophic changes in chondrocytes leading to cartilage degeneration in OA. In this study, we analyzed the molecular response of chondrocytes under condition of this type of stimulation to identify a molecular therapeutic target. Stimulated macrophages promoted hypertrophic changes in chondrocytes resulting in production of matrix-degrading enzymes of cartilage. Among the top-upregulated genes, FliI was found to be released from activated chondrocytes and exerted autocrine/paracrine effects on chondrocytes leading to an increase in expression of catabolic and hypertrophic factors. Silencing FliI in stimulated cells significantly reduced expression of catabolic and hypertrophic factors in cocultured chondrocytes. Our further results demonstrated that the FliI-TLR4-ERK1/2 axis is involved in the hypertrophic signaling of chondrocytes and catabolism of cartilage. Our findings provide a new insight into the pathogenesis of OA and identify a potentially new molecular target for diagnostics and therapeutics.

•

Activated macrophages promote the secretion of FliI from chondrocytes

•

FliI acts as a DAMP-triggering molecule in cartilage

•

FliI promotes chondrocyte hypertrophy and cartilage catabolism

•

FliI represents attractive target for therapeutic intervention

Recommended core outcome instruments for health-related quality of life, long-term control and itch intensity in atopic eczema trials: results of the HOME VII consensus meeting

Background

The Harmonising Outcome Measures for Eczema (HOME) initiative has established a core outcome set of domains for atopic eczema (AE) clinical trials. Previous consensus meetings have agreed on preferred instruments for clinician‐reported signs (Eczema Area and Severity Index, EASI) and patient‐reported symptoms (Patient‐Oriented Eczema Measure, POEM). This paper reports consensus decisions from the HOME VII meeting.

Objectives

To complete the core outcome set for AE by agreeing on core outcome instruments for the domains of quality of life (QoL), long‐term control and itch intensity.

Methods

A face‐to‐face consensus meeting was held in Tokyo, Japan (8–10 April 2019) including 75 participants (49 healthcare professionals/methodologists, 14 patients, 12 industry representatives) from 16 countries. Consensus decisions were made by presentations of evidence, followed by whole and small group discussions and anonymous voting using predefined consensus rules.

Results

It was agreed by consensus that QoL should be measured using the Dermatology Life Quality Index (DLQI) for adults, the Children’s Dermatology Life Quality Index (CDLQI) for children and the Infant’s Dermatology Quality of Life Index (IDQoL) for infants. For long‐term control, the Recap of Atopic Eczema (RECAP) instrument or the Atopic Dermatitis Control Test (ADCT) should be used. Consensus was not reached over the frequency of data collection for long‐term control. The peak itch numerical rating scale (NRS)‐11 past 24 h was recommended as an additional instrument for the symptom domain in trials of older children and adults. Agreement was reached that all core outcome instruments should be captured at baseline and at the time of primary outcome assessment as a minimum.

Conclusions

For now, the core outcome set for clinical trials in AE is complete. The specified domains and instruments should be used in all new clinical trials and systematic reviews of eczema treatments.

What is already known about this topic?

Core outcomes sets improve the design and reporting of clinical trials, reduce selective outcome reporting bias and facilitate meta‐analysis of results in systematic reviews.

The HOME core outcome set for eczema recommends the inclusion of four core domains in all atopic eczema trials: clinician‐reported signs, patient‐reported symptoms, health‐related quality of life (HrQoL) and long‐term control.

Clinician‐reported signs should be captured using the Eczema Area and Severity Index (EASI) and patient‐reported symptoms using the Patient‐Oriented Eczema Measure (POEM).

What does this study add?

The HOME core outcome set is now complete and recommended core outcome instruments have been agreed on for all four domains.

Core outcome instruments for HrQoL: Dermatology Life Quality Index (DLQI) for adults, Children’s Dermatology Life Quality Index (CDLQI) for children and Infant’s Dermatology Quality of Life Index (IDQoL) for infants.

Core outcome instruments for long‐term control: either the Recap of Atopic Eczema (RECAP) or the Atopic Dermatitis Control Test (ADCT).

In addition, itch intensity should be measured using the peak NRS‐11 past 24 h for trials including older children and adults.

What are the clinical implications of this work?

If all future trials of eczema treatments include the HOME core outcome instruments, then trial results will be more readily incorporated into meta‐analyses in systematic reviews and clinical care will be informed by the best available evidence.

Linked Comment: D.F. Murrell and C.F. Paul. Br J Dermatol 2021; 185:13–14.

Recommended core outcome instruments for health-related quality of life, long-term control and itch intensity in atopic eczema trials: results of the HOME VII consensus meeting

BACKGROUND

The Harmonising Outcome Measures for Eczema (HOME) initiative has established a core outcome set of domains for atopic eczema clinical trials. Previous consensus meetings have agreed upon preferred instruments for clinician-reported signs (Eczema Area and Severity Index - EASI) and patient-reported symptoms (Patient-Oriented Eczema Measure - POEM). This paper reports consensus decisions from the HOME VII meeting.

OBJECTIVE

To complete the core outcome set for atopic eczema by agreeing upon core outcome instruments for the domains of quality of life, long-term control and itch intensity.

METHODS

Face-to-face consensus meeting held in Tokyo, Japan (8th to 10th April, 2019) including 74 participants (47 healthcare professionals/methodologists, 14 patients, 13 industry representatives), from 16 countries. Consensus decisions were made by presentations of evidence, followed by whole and small group discussions and anonymous voting using pre-defined consensus rules.

RESULTS

It was agreed by consensus that quality of life should be measured using the Dermatology Life Quality Index (DLQI) for adults, the Children's Dermatology Life Quality Index (CDLQI) for children, and the Infant's Dermatology Quality of Life Index (IDQoL) for infants. For long-term control, the Recap of Atopic Eczema (RECAP) instrument or the Atopic Dermatitis Control Test (ADCT) should be used. Consensus was not reached over the frequency of data collection for long-term control. The peak itch numerical rating scale(NRS)-11 past 24 hours was recommended as an additional instrument for the symptom domain in trials of older children and adults. Agreement was reached that all core outcome instruments should be captured at baseline and at the time of primary outcome assessment as a minimum.

CONCLUSIONS

For now, the core outcome set for clinical trials in atopic eczema is complete. The specified domains and instruments should be used in all new clinical trials and systematic reviews of eczema treatments.

Blockade of XCL1/Lymphotactin Ameliorates Severity of Periprosthetic Osteolysis Triggered by Polyethylene-Particles

Periprosthetic osteolysis induced by orthopedic implant-wear particles continues to be the leading cause of arthroplasty failure in majority of patients. Release of the wear debris results in a chronic local inflammatory response typified by the recruitment of immune cells, including macrophages. The cellular mediators derived from activated macrophages favor the osteoclast-bone resorbing activity resulting in bone loss at the site of implant and loosening of the prosthetic components. Emerging evidence suggests that chemokines and their receptors are involved in the progression of periprosthetic osteolysis associated with aseptic implant loosening. In the current study, we investigated the potential role of chemokine C-motif-ligand-1 (XCL1) in the pathogenesis of inflammatory osteolysis induced by wear particles. Expressions of XCL1 and its receptor XCR1 were evident in synovial fluids and tissues surrounding hip-implants of patients undergoing revision total hip arthroplasty. Furthermore, murine calvarial osteolysis model induced by ultra-high molecular weight polyethylene (UHMWPE) particles was used to study the role of XCL1 in the development of inflammatory osteolysis. Mice received single injection of recombinant XCL1 onto the calvariae after implantation of particles exhibited significantly greater osteolytic lesions than the control mice. In contrast, blockade of XCL1 by neutralizing antibody significantly reduced bone erosion and the number of bone-resorbing mature osteoclasts induced by UHMWPE particles. In consistence with the results, transplantation of XCL1-soaked sponge onto calvariae caused osteolytic lesions coincident with excessive infiltration of inflammatory cells and osteoclasts. These results suggested that XCL1 might be involved in the development of periprosthetic osteolysis through promoting infiltration of inflammatory cells and bone resorbing-osteoclasts. Our further results demonstrated that supplementing recombinant XCL1 to cultured human monocytes stimulated with the receptor activator of nuclear factor kappa-B ligand (RANKL) promoted osteoclastogenesis and the osteoclast-bone resorbing activity. Moreover, recombinant XCL1 promoted the expression of inflammatory and osteoclastogenic factors, including IL-6, IL-8, and RANKL in human differentiated osteoblasts. Together, these results suggested the potential role of XCL1 in the pathogenesis of periprosthetic osteolysis and aseptic loosening. Our data broaden knowledge of the pathogenesis of aseptic prosthesis loosening and highlight a novel molecular target for therapeutic intervention.

Transcriptional profiling of murine macrophages stimulated with cartilage fragments revealed a strategy for treatment of progressive osteoarthritis

Accumulating evidence suggests that synovitis is associated with osteoarthritic process. Macrophages play principal role in development of synovitis. Our earlier study suggests that interaction between cartilage fragments and macrophages exacerbates osteoarthritic process. However, molecular mechanisms by which cartilage fragments trigger cellular responses remain to be investigated. Therefore, the current study aims at analyzing molecular response of macrophages to cartilage fragments. To this end, we analyzed the transcriptional profiling of murine macrophages exposed to cartilage fragments by RNA sequencing. A total 153 genes were differentially upregulated, and 105 genes were down-regulated in response to cartilage fragments. Bioinformatic analysis revealed that the most significantly enriched terms of the upregulated genes included scavenger receptor activity, integrin binding activity, TNF signaling, and toll-like receptor signaling. To further confirm our results, immunohistochemical staining was performed to detected regulated molecules in synovial tissues of OA patients. In consistence with RNA-seq results, MARCO, TLR2 and ITGα5 were mainly detected in the intima lining layer of synovial tissues. Moreover, blockade of TLR2 or ITGα5 but not Marco using specific antibody significantly reduced production of TNF-α in stimulated macrophages by cartilage fragments. Our data suggested that blocking TLR2 or ITGα5 might be promising therapeutic strategy for treating progressive osteoarthritis.

Benign hilar bile duct strictures resected as perihilar cholangiocarcinoma

BACKGROUND

Differentiation between perihilar cholangiocarcinoma (PHCC) and benign strictures is frequently difficult. The aim of this study was to investigate the incidence and long-term outcome of patients with tumours resected because of suspicion of PHCC, which ultimately turned out to be benign (malignancy masquerade).

METHODS

Patients who underwent surgical resection with a diagnosis of PHCC between 2001 and 2016 were reviewed retrospectively.

RESULTS

Among 707 consecutive patients, 685 had PHCC and the remaining 22 (3·1 per cent) had benign biliary stricture. All patients with benign disease underwent major hepatectomy, with no deaths. Preoperative histological assessment using bile duct biopsy or aspiration cytology had a high specificity (90 per cent), low sensitivity (62 per cent) and unsatisfactory accuracy (63 per cent). Despite the increasing use of histological assessment, the incidence of benign strictures resected did not decrease over time, being 0·9 per cent in 2001-2004, 4·0 per cent in 2005-2008, 3·8 per cent in 2009-2012 and 2·9 per cent in 2013-2016. The final pathology of benign strictures included IgG4-related sclerosing cholangitis (9 patients), hepatolithiasis (4), granulomatous cholangitis (3), non-specific chronic cholangitis (3), benign strictures after cholecystectomy (2), and a benign stricture possibly caused by parasitic infection (1). The 10-year overall survival rate for the 22 patients with benign stricture was 87 per cent, without recurrence of biliary stricture.

CONCLUSION

The incidence of benign strictures resected as PHCC as a proportion of all resections was relatively low, at 3·1 per cent. Currently, unnecessary surgery for suspected PHCC is unavoidable.

Clinical value of additional resection of a margin-positive distal bile duct in perihilar cholangiocarcinoma

Background

Little is known about the effect of additional resection for a frozen-section-positive distal bile duct margin (DM) in perihilar cholangiocarcinoma.

Methods

Patients who underwent surgical resection for perihilar cholangiocarcinoma between 2001 and 2015 were analysed retrospectively, focusing on the DM.

Results

Of 558 consecutive patients who underwent frozen-section examination for a DM, 74 (13·3 per cent) had a frozen-section-positive DM with invasive cancer or carcinoma in situ. Eventually, 53 patients underwent additional resection (bile duct resection in 44 and pancreatoduodenectomy in 9), whereas the remaining 21 patients did not. Ultimately, R0 resection was achieved in 30 of the 53 patients (57 per cent). No patient who underwent additional resection died from surgical complications. The 44 patients with additional bile duct resection had a 5-year overall survival rate of 31 per cent. Overall survival of the nine patients who had pancreatoduodenectomy was better, with a 10-year rate of 67 per cent. Survival of the 21 patients without additional resection was dismal: all died within 5 years. Multivariable analyses identified nodal status and additional resection as independent prognostic factors (lymph node metastasis: hazard ratio (HR) 2·26, 95 per cent c.i. 1·26 to 4·07; bile duct resection versus no additional resection: HR 0·32, 0·17 to 0·60; pancreatoduodenectomy versus no additional resection: HR 0·08, 0·02 to 0·29).

Conclusion

Additional resection for frozen-section-positive DM in perihilar cholangiocarcinoma frequently yields R0 margins. It offers a better chance of long-term survival, and thus should be performed in carefully selected patients.

Major hepatectomy with or without pancreatoduodenectomy for advanced gallbladder cancer

BACKGROUND

The indications for major hepatectomy for gallbladder cancer either with or without pancreatoduodenectomy remain controversial. The clinical value of these extended procedures was evaluated in this study.

METHODS

Patients who underwent major hepatectomy for gallbladder cancer between 1996 and 2016 were identified from a prospectively compiled database. Postoperative outcomes and overall survival were compared between patients undergoing major hepatectomy alone or combined with pancreatoduodenectomy (HPD).

RESULTS

Seventy-nine patients underwent major hepatectomy alone and 38 patients had HPD. The patients who underwent HPD were more likely to have T4 disease (P < 0·001), nodal metastasis (P = 0·015) and periaortic nodal metastasis (P = 0·006), but were less likely to receive adjuvant therapy (P = 0·006). HPD was associated with a high incidence of grade III or higher complications (P = 0·002) and death (P = 0·037). Overall survival was longer in patients who underwent major hepatectomy alone than in patients who underwent HPD (median survival time 32 versus 10 months; P < 0·001). In multivariable analysis, surgery in the early period (1996-2006) (P = 0·002), pathological T4 disease (P = 0·005) and distant metastasis (P < 0·001) were associated with shorter overall survival, and cystic duct tumour (P = 0·002) with longer overall survival.

CONCLUSION

Major hepatectomy alone for gallbladder cancer contributes to favourable overall survival with low morbidity and mortality, whereas HPD is associated with poor overall survival and high morbidity and mortality rates. HPD may eradicate locally spreading gallbladder cancer; however, the indication for the procedure is questioned from an oncological viewpoint.

Randomized clinical trial of adjuvant gemcitabine chemotherapy versus observation in resected bile duct cancer

BACKGROUND

Although some retrospective studies have suggested the value of adjuvant therapy, no recommended standard exists in bile duct cancer. The aim of this study was to test the hypothesis that adjuvant gemcitabine chemotherapy would improve survival probability in resected bile duct cancer.

METHODS

This was a randomized phase III trial. Patients with resected bile duct cancer were assigned randomly to gemcitabine and observation groups, which were balanced with respect to lymph node status, residual tumour status and tumour location. Gemcitabine was given intravenously at a dose of 1000 mg/m² , administered on days 1, 8 and 15 every 4 weeks for six cycles. The primary endpoint was overall survival, and secondary endpoints were relapse-free survival, subgroup analysis and toxicity.

RESULTS

Some 225 patients were included (117 gemcitabine, 108 observation). Baseline characteristics were well balanced between the gemcitabine and observation groups. There were no significant differences in overall survival (median 62·3 versus 63·8 months respectively; hazard ratio 1·01, 95 per cent c.i. 0·70 to 1·45; P = 0·964) and relapse-free survival (median 36·0 versus 39·9 months; hazard ratio 0·93, 0·66 to 1·32; P = 0·693). There were no survival differences between the two groups in subsets stratified by lymph node status and margin status. Although haematological toxicity occurred frequently in the gemcitabine group, most toxicities were transient, and grade 3/4 non-haematological toxicity was rare.

CONCLUSION

The survival probability in patients with resected bile duct cancer was not significantly different between the gemcitabine adjuvant chemotherapy group and the observation group. Registration number: UMIN 000000820 (http://www.umin.ac.jp/).

Reappraisal of classification of distal cholangiocarcinoma based on tumour depth

Background

In the eighth edition of the AJCC cancer staging classification, the T system for distal cholangiocarcinoma (DCC) has been revised from a layer-based to a depth-based approach. The aim of this study was to propose an optimal T classification using a measured depth in resectable DCC.

Methods

Patients who underwent pancreatoduodenectomy for DCC at 32 hospitals between 2001 and 2010 were included. The distance between the level of the naive bile duct and the deepest cancer cells was measured as depth of invasion (DOI). Invasive cancer foci were measured as invasive tumour thickness (ITT). Log rank χ2 scores were used to determine the cut-off points, and concordance index (C-index) to assess the survival discrimination of each T system.

Results

Among 404 patients, DOI was measurable in 182 (45·0 per cent) and ITT was measurable in all patients, with median values of 2·3 and 5·6 mm respectively. ITT showed a positive correlation with DOI (rs = 0·854, P &lt; 0·001), and the cut-off points for prognosis were 1, 5 and 10 mm. Median survival time was shorter with increased ITT: 12·4 years for ITT below 1 mm, 5·2 years for ITT at least 1 mm but less than 5 mm, 3·0 years for ITT at least 5 mm but less than 10 mm, and 1·5 years for ITT 10 mm or more (P &lt; 0·001). This classification exhibited more favourable prognostic discrimination than the T systems of the seventh and eighth editions of the AJCC (C-index 0·646, 0·622 and 0·624 respectively).

Conclusion

ITT is an accurate approach for depth assessment in DCC. The four-tier ITT classification with cut-off points of 1, 5 and 10 mm seems to be a better T system than those in the seventh and eighth editions of the AJCC classification.

Ethanol ablation for refractory bile leakage after complex hepatectomy

BACKGROUND

Only a few reports exist on the use of ethanol ablation for posthepatectomy bile leakage. The aim of this study was to assess the value of ethanol ablation in refractory bile leakage.

METHODS

Medical records of consecutive patients who underwent a first hepatobiliary resection with bilioenteric anastomosis between 2007 and 2016 were reviewed retrospectively, with special attention to bile leakage and ethanol ablation therapy. Bile leakage was graded as A/B1/B2 according to the International Study Group of Liver Surgery definition. Absolute ethanol was injected into the target bile duct during fistulography.

RESULTS

Of the 609 study patients, 237 (38·9 per cent) had bile leakage, including grade A in 33, grade B1 in 18 and grade B2 in 186. Left trisectionectomy was more often associated with grade B2 bile leakage than other types of hepatectomy (P < 0·001). Of 186 patients with grade B2 bile leakage, 31 underwent ethanol ablation therapy. Ethanol ablation was started a median of 34 (range 15-122) days after hepatectomy. The median number of treatments was 3 (1-7), and the total amount of ethanol used was 15 (3-71) ml. Complications related to ethanol ablation included transient fever (27 patients) and mild pain (13). Following ethanol ablation, bile leakage resolved in all patients and drains were removed. The median interval between the first ablation and drain removal was 28 (1-154) days.

CONCLUSION

Ethanol ablation is safe and effective, and may be a treatment option for refractory bile leakage.

Pancreatoduodenectomy with portal vein resection for distal cholangiocarcinoma

BACKGROUND

Little is known about the value of portal vein (PV) resection in distal cholangiocarcinoma. The aim of this study was to evaluate the clinical significance of PV resection in distal cholangiocarcinoma.

METHODS

Patients who underwent pancreatoduodenectomy (PD) for distal cholangiocarcinoma between 2001 and 2010 at one of 31 hospitals in Japan were reviewed retrospectively with special attention to PV resection. Short- and long-term outcomes were evaluated.

RESULTS

In the study interval, 453 consecutive patients with distal cholangiocarcinoma underwent PD, of whom 31 (6·8 per cent) had combined PV resection. The duration of surgery (510 versus 427 min; P = 0·005) and incidence of blood transfusion (48 versus 30·7 per cent; P = 0·042) were greater in patients who had PV resection than in those who did not. Postoperative morbidity and mortality were no different in the two groups. Several indices of tumour progression, including high T classification, lymphatic invasion, perineural invasion, pancreatic invasion and lymph node metastasis, were more common in patients who had PV resection. Consequently, the incidence of R1/2 resection was higher in this group (32 versus 11·8 per cent; P = 0·004). Survival among the 31 patients with PV resection was worse than that for the 422 patients without PV resection (15 versus 42·4 per cent at 5 years; P < 0·001). Multivariable analyses revealed that age, blood loss, histological grade, perineural invasion, pancreatic invasion, lymph node metastasis and surgical margin were independent risk factors for overall survival. PV resection was not an independent risk factor.

CONCLUSION

PV invasion in distal cholangiocarcinoma is associated with locally advanced disease and several negative prognostic factors. Survival for patients who have PV resection is poor even after curative resection.

Surgical resection for Bismuth type IV perihilar cholangiocarcinoma

BACKGROUND

Bismuth type IV perihilar cholangiocarcinoma has traditionally been categorized as unresectable disease. The aim of this study was to review experience with a resection-based strategy in patients who have type IV perihilar cholangiocarcinoma.

METHODS

Medical records of consecutive patients with a diagnosis of type IV perihilar cholangiocarcinoma between 2006 and 2015 were reviewed retrospectively. Primary outcomes assessed were surgical results and long-term survival.

RESULTS

Of the 332 patients with type IV tumour, 216 (65·1 per cent) underwent resection. Left hepatic trisectionectomy was the most common procedure (112 patients). Combined vascular resection was performed in 131 patients. Median duration of operation was 607 (range 356-1045) min, and blood loss was 1357 (209-10 349) ml. Complications of Clavien-Dindo grade III or more developed in 90 patients (41·7 per cent) and four (1·9 per cent) died from complications within 90 days. Survival rates were better for the 216 patients whose tumours were resected than for the 116 patients with unresected tumours (32·8 versus 1·5 per cent at 5 years; P < 0·001). Patients with pN0 M0 disease after resection had a favourable 5-year survival rate of 53 per cent. Percutaneous transhepatic biliary drainage, blood transfusion, lymph node metastasis and distant metastasis were identified as independent negative prognostic factors for survival.

CONCLUSION

Although resection for type IV tumour is technically demanding with high morbidity, it can be performed with low mortality and offers better survival probability in selected patients.

Recurrence after resection with curative intent for distal cholangiocarcinoma

BACKGROUND

Few studies have been conducted on patterns of recurrence after resection for distal cholangiocarcinoma (DCC). The aim of this study was to investigate the incidence and pattern of recurrence after resection of DCC, and to evaluate prognostic factors for time to recurrence and recurrence-free survival (RFS).

METHODS

Patients who underwent pancreatoduodenectomy with curative intent for DCC between 2001 and 2010 at one of 30 hospitals in Japan were reviewed retrospectively, with special attention to recurrence patterns. The Cox proportional hazards model was used for multivariable analysis.

RESULTS

In the study interval, 389 patients underwent pancreatoduodenectomy for DCC with R0/M0 status. Recurrence developed in 213 patients (54·8 per cent). The estimated cumulative probability of recurrence was 54·3 per cent at 5 years. An initial locoregional recurrence occurred in 55 patients (14·1 per cent) and initial distant recurrence in 168 (43·2 per cent), most commonly in the liver. Isolated initial locoregional recurrence occurred in 45 patients (11·6 per cent). Independent prognostic factors for time to recurrence and RFS were perineural invasion (P = 0·001 and P = 0·009 respectively), pancreatic invasion (both P < 0·001) and lymph node metastasis (both P < 0·001). RFS worsened as the number of risk factors increased: the 5-year RFS rate was 70·6 per cent for patients without any risk factors, 50·3 per cent for patients with one factor, 31·8 per cent for those with two factors, and 13·4 per cent when three factors were present.

CONCLUSION

More than half of patients with DCC experienced recurrence after R0 resection, usually within 5 years. Perineural invasion, pancreatic invasion and positive nodal involvement are risk factors for recurrence.

Clinical significance of dual-energy CT-derived iodine quantification in the diagnosis of metastatic LN in colorectal cancer

BACKGROUND

The purpose of this study was to evaluate the diagnostic value of dual-energy computed tomography (DECT) in detecting lymph node (LN) metastasis in patients with colorectal cancer.

METHODS

Data from 81 LNs from 28 patients with colorectal adenocarcinoma were retrospectively analyzed. All patients received DECT before surgery without any neoadjuvant therapy. The diagnostic value was assessed using the iodine concentration (IC).

RESULTS

In the pathological findings, 35 (43.2%) LNs from 13 patients were metastatic and 46 (56.8%) LNs from 17 patients were non-metastatic. The mean IC of metastatic LNs in the portal venous phase (PP) was 1.60 mg/ml, which was significantly lower compared with non-metastatic LNs (3.25 mg/ml, p < 0.001). Receiver operating characteristic (ROC) analysis revealed that the IC in PP had the highest ability to discriminate LN metastasis (area under the ROC curve [AUC] 0.932). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of IC in PP (cutoff 2.1 mg/ml) were 87.0%, 88.6%, 85.3%, 90.0%, and 87.9%, respectively. When clinically obvious metastatic LNs in conventional CT findings were excluded, 50 LNs remained (5 metastatic and 45 non-metastatic LNs). In this subgroup analysis, the IC in PP remained the most powerful predictor of metastatic LNs (cutoff: 2.1 mg/ml, AUC 0.933).

CONCLUSIONS

The evaluation of IC in DECT may improve the diagnostic capabilities of discriminating metastatic LNs. This method may be particularly useful when conventional CT findings lead to equivocal results.

Prognostic impact of lymph node metastasis in distal cholangiocarcinoma

BACKGROUND

The aim of the study was to investigate the prognostic impact of lymph node metastasis in cholangiocarcinoma using three different classifications.

METHODS

Patients who underwent pancreaticoduodenectomy for distal cholangiocarcinoma in 24 hospitals in Japan between 2001 and 2010 were included. Survival was calculated by means of the Kaplan-Meier method and differences between subgroups were assessed with the log rank test. The Cox proportional hazards model was used to identify independent predictors of survival. χ(2) scores were calculated to determine the cut-off value of the number of involved nodes, lymph node ratio (LNR) and total lymph node count (TLNC) for discriminating survival.

RESULTS

Some 370 patients were included. The median (range) TLNC was 19 (3-59). Nodal metastasis occurred in 157 patients (42·4 per cent); the median (range) number of involved nodes and LNR were 2 (1-19) and 0·11 (0·02-0·80) respectively. Four or more involved nodes was associated with a significantly shorter median survival (1·3 versus 2·2 years; P = 0·001), as was a LNR of at least 0·17 (1·4 versus 2·3 years; P = 0·002). Involvement of nodes along the common hepatic artery, present in 21 patients (13·4 per cent), was also associated with a shorter survival (median 1·3 versus 2·1 years; P = 0·046). Multivariable analysis among 157 node-positive patients identified the number of involved nodes as an independent prognostic factor (risk ratio 1·87; P = 0·002).

CONCLUSION

The number of involved nodes was a strong predictor of survival in patients with distal cholangiocarcinoma.

Proposal to modify the International Union Against Cancer staging system for perihilar cholangiocarcinomas

BACKGROUND

The International Union Against Cancer (UICC) staging system for perihilar cholangiocarcinoma changed in 2009. The aim of this study was to validate and optimize the UICC system for these tumours.

METHODS

This retrospective study was conducted in eight Japanese hospitals between 2001 and 2010. Perihilar cholangiocarcinoma was defined as a cholangiocarcinoma that involves the hilar bile duct, independent of the presence or absence of a liver mass component. The stratification ability of the UICC tumour node metastasis (TNM) system was compared with that of a modified system.

RESULTS

Of 1352 patients, 35.9, 44.8 and 12.6 per cent had Bismuth type IV tumours, nodal metastasis (N1) and distant metastasis (M1) respectively. T4 tumours (43.2 per cent) and stage IVA (T4 Nany M0; 36.3 per cent) disease were most common. Survival was not significantly different between patients with T3 versus T4 tumours (P = 0.284). Survival for patients with stage IVA disease was comparable to that for patients with stage IIIB tumours (T1-3 N1 M0) (P = 0.426). Vascular invasion, pancreatic invasion, positive margin, N1 and M1 status were identified as independent predictors of survival. When Bismuth type IV tumours were removed from the T4 determinants and N1 tumours grouped together, the modified grouping had a higher linear trend χ2 and likelihood ratio χ2 compared with the original system (245.6 versus 170.3 respectively and 255.8 versus 209.3 respectively).

CONCLUSION

The present data suggest that minimal modification with removal of Bismuth type IV tumours from the T4 determinants and bundling of N1 disease may enhance the prognostic ability of the UICC system. However, this requires validation on an independent data set.

Role of anatomical right hepatic trisectionectomy for perihilar cholangiocarcinoma

BACKGROUND

Right-sided hepatectomy is often selected for perihilar cholangiocarcinoma because the extrahepatic portion of the left hepatic duct is longer than that of the right hepatic duct. However, the length of resected left hepatic duct in right-sided hepatectomy has not been reported.

METHODS

Patients who underwent right-sided hepatectomy for perihilar cholangiocarcinoma were reviewed retrospectively. Trisectionectomies were performed according to a previously reported technique of anatomical right hepatic trisectionectomy. Right hepatectomy was performed according to standard operative procedures. The length of resected left hepatic duct was measured.

RESULTS

Thirty-three patients underwent right trisectionectomy and 141 had a right hemihepatectomy. Patients having a trisectionectomy had more advanced tumours and so required combined portal vein resection more frequently. Duration of surgery and blood loss were similar in the two groups. Morbidity and mortality rates tended to be higher following hemihepatectomy than after trisectionectomy. The mean(s.d.) length of resected left hepatic duct was significantly greater in trisectionectomy than in hemihepatectomy (25·0(6·9) versus 14·8(5·3) mm; P < 0·001). In patients with Bismuth type IV tumours, the percentage of negative left hepatic duct margins was significantly higher for trisectionectomy than for hemihepatectomy (89 versus 57 per cent; P = 0·021). Achievement of R0 resection was similar and survival did not differ between the two groups, despite different tumour load.

CONCLUSION

Compared with right hemihepatectomy, anatomical right hepatic trisectionectomy provides a greater length of resected hepatic duct, leading to a high proportion of negative proximal ductal margins even in patients with Bismuth type IV tumours.

Rectal duplication cyst successfully treated by laparoscopic total mesorectal excision using the prolapsing technique

Congenital alimentary tract duplication is a rare disease. It most frequently occurs in the ileum, with the rectum being the rarest site. Herein, we report a 38-year-old woman who was referred to our hospital because of severe anal pain. On digital examination, a smooth, round, rubbery mass was palpable; it was located 5 cm from the anal verge in the posterior rectal wall. A CT scan demonstrated a 5-cm cystic lesion located anterior to the sacrum that was displacing the rectum anteriorly. Spontaneous remission of the tumor was evident; however, after 5 months of follow-up, the patient experienced the same severe anal pain. MRI demonstrated a recurrent cystic lesion. To prevent further complications and to confirm or deny malignancy, laparoscopic total mesorectal excision using the prolapsing technique was performed. Pathologically, the cystic lesion was diagnosed as a rectal duplication cyst. This is the first report of a rectal duplication cyst successfully treated by laparoscopic total mesorectal excision.

Prospective study of biliary cytology in suspected perihilar cholangiocarcinoma

BACKGROUND

The diagnostic value of biliary cytology for hilar bile duct stricture is uncertain. This study prospectively examined three methods for the evaluation of biliary cytology in a consecutive group of patients.

METHODS

Preoperative bile sampling by aspiration through a drainage catheter (aspiration samples), saline flush through a drainage catheter (saline samples) or direct sampling from a drainage bag (bag samples) was performed in consecutive patients with suspected perihilar cholangiocarcinoma who underwent resection after endoscopic nasobiliary drainage or percutaneous transhepatic biliary drainage. All bile sampling was performed three times on separate days. The accuracy of cytology in the diagnosis of carcinoma was determined.

RESULTS

Of 100 consecutive patients with hilar strictures, 97 had histologically proven cholangiocarcinoma. The proportion of these 97 patients who had a positive finding on cytology in at least one of three sampling sessions was 55 per cent for aspiration samples, 48 per cent for bag samples and 38 per cent for saline samples (P = 0·021, aspiration versus saline). Tumour length correlated significantly with overall positivity. For aspiration samples, sensitivity was 55 per cent, specificity was 100 per cent and accuracy 56·0 per cent.

CONCLUSION

For biliary cytology, sampling by catheter aspiration is more effective than catheter flushing or sampling from a drainage bag. Repeated sampling increases sensitivity. Biliary cytology has modest diagnostic yield, but is easy to perform, highly specific, and can provide a definitive diagnosis.

Percutaneous transhepatic biliary drainage catheter tract recurrence in cholangiocarcinoma

BACKGROUND

The aim of the study was to clarify the incidence, risk factors and treatment of percutaneous transhepatic biliary drainage (PTBD) catheter tract recurrence in patients with resected cholangiocarcinoma.

METHODS

The medical records of 445 patients with perihilar and distal cholangiocarcinoma who underwent resection following PTBD were reviewed retrospectively.

RESULTS

PTBD catheter tract recurrence was detected in 23 patients (5.2 per cent). The mean(s.d.) interval between surgery and onset of the recurrence was 14.4(13.8) months. On multivariable analysis, duration of PTBD (60 days or more), multiple PTBD catheters and macroscopic papillary tumour type were identified as independent risk factors. In four patients with synchronous metastasis, the PTBD sinus tract was resected simultaneously, at the time of initial surgery. Of 19 patients with metachronous metastasis, 15 underwent surgical resection of the metastasis. Survival of the 23 patients with PTBD catheter tract recurrence was poorer than that of the 422 patients without recurrence (median 22.8 versus 27.3 months; P = 0.095). Even after surgical resection of PTBD catheter tract recurrence, survival was poor.

CONCLUSION

PTBD catheter tract recurrence is not unusual. The prognosis for these patients is generally poor, even after resection. To prevent this troublesome complication, endoscopic biliary drainage is first recommended when drainage is indicated.

Value of indocyanine green clearance of the future liver remnant in predicting outcome after resection for biliary cancer

BACKGROUND

It is difficult to predict hepatic functional reserve accurately before major hepatectomy. The aim of this study was to analyse the usefulness of the future liver remnant plasma clearance rate of indocyanine green (ICGK-F, calculated as plasma clearance rate of indocyanine green (ICGK) x proportion of the future liver remnant) in predicting death after major hepatectomy.

METHODS

Data on ICGK and ICGK-F were collected prospectively and analysed retrospectively for 274 patients who underwent right hepatectomy, right trisectionectomy or left trisectionectomy for biliary cancer between 1991 and 2008. The mortality rate and incidence of postoperative complications were analysed. Patients were separated into two groups according to year of operation (85 patients operated on between 1991 and 2000; 189 from 2001 to 2008).

RESULTS

In multiple logistic regression analyses, an ICGK-F less than 0.05 had the strongest impact on the incidence of postoperative mortality (odds ratio 8.06; P < 0.001). The postoperative mortality rate was significantly lower in the later period (P < 0.001). In patients with an ICGK-F value between 0.040 and 0.049, the mortality rate in the early period was 30 per cent, whereas it was only 8 per cent in the later period.

CONCLUSION

An ICGK-F of 0.05 is a useful cut-off value for predicting mortality and morbidity. With careful perioperative patient management in an experienced institution, this cut-off value can be lowered further.

The concept of perihilar cholangiocarcinoma is valid

BACKGROUND

The term perihilar cholangiocarcinoma has been used for all tumours involving or requiring resection of the hepatic confluence. However, it does not distinguish between intrahepatic and extrahepatic hilar tumours, and has no clinicopathological basis. This retrospective study examined whether the concept of perihilar cholangiocarcinoma is valid clinically.

METHODS

Some 250 patients with perihilar cholangiocarcinoma were divided into extrahepatic (EHC, 167 patients) and intrahepatic (IHC, 83) groups based on tumour location. Clinicopathological data were compared between these groups.

RESULTS

Liver, portal vein, venous and lymphatic invasion, and nodal metastasis were more common in IHCs than EHCs, whereas histological grade and incidence of perineural invasion were similar. IHCs were more advanced at the time of surgery; stage III or IV disease was found in 37.7 per cent of EHCs and 59 per cent of IHCs. Survival was marginally better for patients with EHCs than for those with IHCs (29.3 versus 20 per cent at 5 years; P = 0.057), but survival rates were similar for each tumour stage in the American Joint Committee on Cancer classification.

CONCLUSION

Combining EHC and IHC under the term perihilar cholangiocarcinoma is valid, as these tumours have comparable biological behaviour, with similar clinical management depending on stage and invasion.

5-fluorouracil-induced histopathological changes in the central nervous system of rat fetuses

5-Fluorouracil (5-FU), a thymidylate synthesis inhibitor, has been well known to induce developmental anomalies in the craniofacial tissues and limb buds. Recently it was reported that microencephaly was also induced in rat neonates after 5-Fu-treatement in late phase of pregnancy (Kumar et al., 2006). In this study, pregnant rats were treated with 5-Fu (15, 30 or 50 mg/kg) on day 13 of gestation, and their fetuses were examined for histopathological changes, especially in the fetal central nervous system (CNS) at 12, 24 and 48 hours after treatment (HAT). At 12 HAT, an enhancement of pyknosis of neuronal progenitor cells and subsequent loss of dead cells were detected in the CNS in a dose-dependent manner. The severity of such histopathological changes in the CNS was most prominent in the telencephalon (middle and dorsal layers of the ventricular zone) and spinal cord (dorsal area). Pyknotic cells decreased towards 48 HAT in the brain while they increased towards 48 HAT in the spinal cord. Almost all of the nuclei of pyknotic cells were positively stained by TUNEL method and showed characteristics of apoptotic cells under electron microscopy. Therefore, these pyknotic cells were considered to be apoptotic ones. Enhanced apoptosis and reduced mitosis in neuronal progenitor cells in the telencephalon seem to be responsible for the later induction of microencephaly reported by Kumar et al. (2006).

Mountain pine beetle and forest carbon feedback to climate change

The mountain pine beetle (Dendroctonus ponderosae Hopkins, Coleoptera: Curculionidae, Scolytinae) is a native insect of the pine forests of western North America, and its populations periodically erupt into large-scale outbreaks. During outbreaks, the resulting widespread tree mortality reduces forest carbon uptake and increases future emissions from the decay of killed trees. The impacts of insects on forest carbon dynamics, however, are generally ignored in large-scale modelling analyses. The current outbreak in British Columbia, Canada, is an order of magnitude larger in area and severity than all previous recorded outbreaks. Here we estimate that the cumulative impact of the beetle outbreak in the affected region during 2000-2020 will be 270 megatonnes (Mt) carbon (or 36 g carbon m(-2) yr(-1) on average over 374,000 km2 of forest). This impact converted the forest from a small net carbon sink to a large net carbon source both during and immediately after the outbreak. In the worst year, the impacts resulting from the beetle outbreak in British Columbia were equivalent to approximately 75% of the average annual direct forest fire emissions from all of Canada during 1959-1999. The resulting reduction in net primary production was of similar magnitude to increases observed during the 1980s and 1990s as a result of global change. Climate change has contributed to the unprecedented extent and severity of this outbreak. Insect outbreaks such as this represent an important mechanism by which climate change may undermine the ability of northern forests to take up and store atmospheric carbon, and such impacts should be accounted for in large-scale modelling analyses.

Intrahepatic cholangiojejunostomy following hepatobiliary resection

Background

Although intrahepatic cholangiojejunostomy is technically difficult, with recent improvements in surgery it should be possible to perform the anastomosis safely. The aim of this study was to evaluate the incidence of anastomotic leak after intrahepatic cholangiojejunostomy and to identify risk factors for such leakage.

Methods

Intrahepatic cholangiojejunostomy was performed in 423 patients undergoing hepatobiliary resection between January 1991 and December 2005. Anastomotic leak was proven radiographically by leakage from the anastomosis of contrast medium introduced via a biliary drainage tube placed during surgery.

Results

Anastomotic leak occurred in 27 patients (6·4 per cent), and was not related to the number of bile ducts reconstructed. The leak rate decreased significantly from 9·5 per cent (19 of 199) in the first 10 years to 3·6 per cent (eight of 224) in the last 5 years. Anastomotic leak was often followed by infections such as wound infection, intra-abdominal abscess and bacteraemia. Multivariable analysis identified age and intraoperative blood loss as independent risk factors for anastomotic leak. All leaks were treated by maintaining a prophylactically placed drain near the cholangiojejunostomy; neither repeat laparotomy nor percutaneous transhepatic biliary drainage was required.

Conclusion

Although demanding, intrahepatic cholangiojejunostomy can be performed successfully with a relatively low failure rate. Routine use of prophylactic drains and anastomotic stenting allows safe management of anastomotic leak with conservative therapy.