Nationwide validation of the distal fistula risk score (D-FRS)

PURPOSE

Distal pancreatectomy (DP) is associated with a high complication rate of 30-50% with postoperative pancreatic fistula (POPF) as a dominant contributor. Adequate risk estimation for POPF enables surgeons to use a tailor-made approach. Assessment of the risk of POPF prior to DP can lead to the application of preventive strategies. The current study aims to validate the recently published preoperative and intraoperative distal fistula risk score (D-FRS) in a nationwide cohort.

METHODS

This nationwide retrospective Dutch cohort study included all patients after DP for any indication, all of whom were registered in the Dutch Pancreatic Cancer Audit (DPCA) database between 2013 and 2021. The D-FRS was validated by filling in the probability equations with data from this cohort. The predictive capacity of the models was represented by an area under the receiver operating characteristic (AUROC) curve.

RESULTS

A total of 896 patients underwent DP of which 152 (17%) developed POPF of whom 144 grade B (95%) and 8 grade C (5%). The preoperative D-FRS, consisting of the variables pancreatic neck thickness and pancreatic duct diameter, showed an AUROC of 0.73 (95%CI 0.68-0.78). The intraoperative D-FRS, comprising pancreatic neck, duct diameter, BMI, operating time, and soft pancreatic aspect, showed an AUROC of 0.69 (95%CI 0.64-0.74).

CONCLUSION

The current study is the first nationwide validation of the preoperative and intraoperative D-FRS showing acceptable distinguishing capacity for only the preoperative D-FRS for POPF. Therefore, the preoperative score could improve prevention and mitigation strategies such as drain management, which is currently investigated in the multicenter PANDORINA trial.

PROMISE: effect of protein supplementation on fat-free mass preservation after bariatric surgery, a randomized double-blind placebo-controlled trial

INTRODUCTION

Protein malnutrition after bariatric surgery is a severe complication and leads to significant morbidity. Previous studies have shown that protein intake and physical activity are the most important factors in the preservation of fat-free mass during weight loss. Low protein intake is very common in patients undergoing bariatric surgery despite dietary counseling. Protein powder supplements might help patients to achieve the protein intake recommendations after bariatric surgery and could therefore contribute to preserve fat-free mass. This double-blind randomized placebo-controlled intervention study aims to assess the effect of a daily consumed clear protein powder shake during the first 6 months after bariatric surgery on fat-free mass loss in the first 12 months after laparoscopic Roux-en-Y gastric bypass (LRYGB).

METHODS AND ANALYSIS

Inclusion will take place at the outpatient clinic of the bariatric expertise center for obesity of the Maasstad Hospital. Patients will be randomly assigned to either the intervention or control group before surgery. The intervention group will receive a clear protein powder shake of 200 ml containing 20 g of whey protein dissolved in water which should be taken daily during the first 6 months after LRYGB on top of their normal postoperative diet. The control group will receive an isocaloric, clear, placebo shake containing maltodextrine. Postoperative rehabilitation and physiotherapeutical guidance will be standardized and similar in both groups. Also, both groups will receive the same dietary advice from specialized dieticians. The main study parameter is the percentage of fat-free mass loss 6 months after surgery, assessed by multi-frequency bioelectrical impedance analysis (MF-BIA).

ETHICS AND DISSEMINATION

The protocol, version 2 (February 20, 2022) has been approved by the Medical Research Ethics Committees United (MEC-U) (NL 80414.100.22). The results of this study will be submitted to peer-reviewed journals.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05570474. Registered on October 5, 2022.

T and B Cell Composition and Cytokine Producing Capacity Before and After Bariatric Surgery

Morbid obesity is associated with a chronic state of low-grade inflammation, which may lead to accelerated differentiation of T and B cells. These differentiated immune cells are strongly cytotoxic and have an increased pro-inflammatory cytokine producing capacity. Furthermore, the anti-inflammatory function of the T and B cells decreases. The aim of this study was to evaluate the effect of morbid obesity on the subset profile and cytokine producing capacity of T and B cells. Subsequently, we assessed whether bariatric surgery affected the subset profile and cytokine producing capacity of these cells. We determined the proportion of T and B cell subsets and their cytokine producing capacity in peripheral blood collected from 23 morbidly obese patients before and three months after bariatric surgery using flow-cytometry. We compared this with the results of 25 lean controls. Both CD4+ and CD8+ T cells showed a more differentiated subset profile in morbidly obese patients as compared to lean controls, which was not recovered three months after bariatric surgery. The B cell composition of morbidly obese patients after bariatric surgery adjusted towards the profile of lean controls. However, the IL-2 and IFN-γ producing capacity of CD8+ T cells and the IL-2, IFN-γ, TNF-α and IL-10 producing capacity of B cells was not restored three months after bariatric surgery. In conclusion, the data suggest that the immune system has the capacity to recover from the detrimental effects of morbid obesity within three months after bariatric surgery in terms of cell composition; however, this was not seen in terms of cytokine producing capacity. The full restoration of the immune system after bariatric surgery may thus take longer.

Completion pancreatectomy or a pancreas-preserving procedure during relaparotomy for pancreatic fistula after pancreatoduodenectomy: a multicentre cohort study and meta-analysis

BACKGROUND

Despite the fact that primary percutaneous catheter drainage has become standard practice, some patients with pancreatic fistula after pancreatoduodenectomy ultimately undergo a relaparotomy. The aim of this study was to compare completion pancreatectomy with a pancreas-preserving procedure in patients undergoing relaparotomy for pancreatic fistula after pancreatoduodenectomy.

METHODS

This retrospective cohort study of nine institutions included patients who underwent relaparotomy for pancreatic fistula after pancreatoduodenectomy from 2005-2018. Furthermore, a systematic review and meta-analysis were performed according to the PRISMA guidelines.

RESULTS

From 4877 patients undergoing pancreatoduodenectomy, 786 (16 per cent) developed a pancreatic fistula grade B/C and 162 (3 per cent) underwent a relaparotomy for pancreatic fistula. Of these patients, 36 (22 per cent) underwent a completion pancreatectomy and 126 (78 per cent) a pancreas-preserving procedure. Mortality was higher after completion pancreatectomy (20 (56 per cent) versus 40 patients (32 per cent); P = 0.009), which remained after adjusting for sex, age, BMI, ASA score, previous reintervention, and organ failure in the 24 h before relaparotomy (adjusted odds ratio 2.55, 95 per cent c.i. 1.07 to 6.08). The proportion of additional reinterventions was not different between groups (23 (64 per cent) versus 84 patients (67 per cent); P = 0.756). The meta-analysis including 33 studies evaluating 745 patients, confirmed the association between completion pancreatectomy and mortality (Mantel-Haenszel random-effects model: odds ratio 1.99, 95 per cent c.i. 1.03 to 3.84).

CONCLUSION

Based on the current data, a pancreas-preserving procedure seems preferable to completion pancreatectomy in patients in whom a relaparotomy is deemed necessary for pancreatic fistula after pancreatoduodenectomy.

Clinical relevant pancreatic fistula after pancreatoduodenectomy: when negative amylase levels tell the truth

Drain Amylase level are routinely determined to diagnose pancreatic fistula after Pancreatocoduodenectomy. Consensus is lacking regarding the cut-off value of amylase to diagnosis clinically relevant postoperative pancreatic fistulae (POPF). The present study proposes a model based on Amylase Value in the Drain (AVD) measured in the first three postoperative days to predict a POPF. Amylase cut-offs were selected from a previous published systematic review and the accuracy were validated in a multicentre database from 12 centres in 2 countries. The present study defined POPF the 2016 ISGPS criteria (3 times the upper limit of normal serum amylase). A learning machine method was used to correlate AVD with the diagnosis of POPF. Overall, 454 (27%) of 1638 patients developed POPF. Machine learning excluded a clinically relevant postoperative pancreatic fistulae with an AUC of 0.962 (95% CI 0.940-0.984) in the first five postoperative days. An AVD at a cut-off of 270 U/L in 2 days in the first three postoperative days excluded a POPF with an AUC of 0.869 (CI 0.81-0.90, p < 0.0001). A single AVD in the first three postoperative days may not exclude POPF after pancreatoduodenectomy. The levels should be monitored until day 3 and have two negative values before removing the drain. In the group with a positive level, the drain should be kept in and AVD monitored until postoperative day five.

Microscopic resection margin status in pancreatic ductal adenocarcinoma - A nationwide analysis

INTRODUCTION

First, this study aimed to assess the prognostic value of different definitions for resection margin status on disease-free survival (DFS) and overall survival (OS) in pancreatic ductal adenocarcinoma (PDAC). Second, preoperative predictors of direct margin involvement were identified.

MATERIALS AND METHODS

This nationwide observational cohort study included all patients who underwent upfront PDAC resection (2014-2016), as registered in the prospective Dutch Pancreatic Cancer Audit. Patients were subdivided into three groups: R0 (≥1 mm margin clearance), R1 (<1 mm margin clearance) or R1 (direct margin involvement). Survival was compared using multivariable Cox regression analysis. Logistic regression with baseline variables was performed to identify preoperative predictors of R1 (direct).

RESULTS

595 patients with a median OS of 18 months (IQR 10-32 months) months were analysed. R0 (≥1 mm) was achieved in 277 patients (47%), R1 (<1 mm) in 146 patients (24%) and R1 (direct) in 172 patients (29%). R1 (direct) was associated with a worse OS, as compared with both R0 (≥1 mm) (hazard ratio (HR) 1.35 [95% and confidence interval (CI) 1.08-1.70); P < 0.01) and R1 (<1 mm) (HR 1.29 [95%CI 1.01-1.67]; P < 0.05). No OS difference was found between R0 (≥1 mm) and R1 (<1 mm) (HR 1.05 [95% CI 0.82-1.34]; P = 0.71). Preoperative predictors associated with an increased risk of R1 (direct) included age, male sex, performance score 2-4, and venous or arterial tumour involvement.

CONCLUSION

Resection margin clearance of <1 mm, but without direct margin involvement, does not affect survival, as compared with a margin clearance of ≥1 mm. Given that any vascular tumour involvement on preoperative imaging was associated with an increased risk of R1 (direct) resection with upfront surgery, neoadjuvant therapy might be considered in these patients.

Impact of nationwide enhanced implementation of best practices in pancreatic cancer care (PACAP-1): a multicenter stepped-wedge cluster randomized controlled trial

Background

Pancreatic cancer has a very poor prognosis. Best practices for the use of chemotherapy, enzyme replacement therapy, and biliary drainage have been identified but their implementation in daily clinical practice is often suboptimal. We hypothesized that a nationwide program to enhance implementation of these best practices in pancreatic cancer care would improve survival and quality of life.

Methods/design

PACAP-1 is a nationwide multicenter stepped-wedge cluster randomized controlled superiority trial. In a per-center stepwise and randomized manner, best practices in pancreatic cancer care regarding the use of (neo)adjuvant and palliative chemotherapy, pancreatic enzyme replacement therapy, and metal biliary stents are implemented in all 17 Dutch pancreatic centers and their regional referral networks during a 6-week initiation period. Per pancreatic center, one multidisciplinary team functions as reference for the other centers in the network. Key best practices were identified from the literature, 3 years of data from existing nationwide registries within the Dutch Pancreatic Cancer Project (PACAP), and national expert meetings. The best practices follow the Dutch guideline on pancreatic cancer and the current state of the literature, and can be executed within daily clinical practice. The implementation process includes monitoring, return visits, and provider feedback in combination with education and reminders. Patient outcomes and compliance are monitored within the PACAP registries. Primary outcome is 1-year overall survival (for all disease stages). Secondary outcomes include quality of life, 3- and 5-year overall survival, and guideline compliance. An improvement of 10% in 1-year overall survival is considered clinically relevant. A 25-month study duration was chosen, which provides 80% statistical power for a mortality reduction of 10.0% in the 17 pancreatic cancer centers, with a required sample size of 2142 patients, corresponding to a 6.6% mortality reduction and 4769 patients nationwide.

Discussion

The PACAP-1 trial is designed to evaluate whether a nationwide program for enhanced implementation of best practices in pancreatic cancer care can improve 1-year overall survival and quality of life.

Trial registration

ClinicalTrials.gov, NCT03513705. Trial opened for accrual on 22th May 2018.

The role of abdominal drainage in pancreatic resection - A multicenter validation study for early drain removal

BACKGROUND

Abdominal drainage and the timing of drain removal in patients undergoing pancreatic resection are under debate. Early drain removal after pancreatic resection has been reported to be safe with a low risk for clinical relevant postoperative pancreatic fistula (CR-POPF) when drain amylase on POD1 is < 5000U/L. The aim of this study was to validate this algorithm in a large national cohort.

METHODS

Patients registered in the Dutch Pancreatic Cancer Audit (2014-2016) who underwent pancreatoduodenectomy, distal pancreatectomy or enucleation were analysed. Data on post-operative drain amylase levels, drain removal, postoperative pancreatic fistulae were collected. Univariate and multivariate analysis using a logistic regression model were performed. The primary outcome measure was grade B/C pancreatic fistula (CR-POPF).

RESULTS

Among 1402 included patients, 433 patients with a drain fluid amylase level of <5000U/L on POD1, 7% developed a CR-POPF. For patients with an amylase level >5000U/L the CR-POPF rate was 28%. When using a cut-off point of 2000U/L or 1000U/L during POD1-3, the CR-POPF rates were 6% and 5% respectively. For patients with an amylase level of >2000U/L and >1000UL during POD 1-3 the CR-POPF rates were 26% and 22% respectively (n = 223). Drain removal on POD4 or thereafter was associated with more complications (p = 0.004). Drain amylase level was shown to be the most statistically significant predicting factor for CR-POPF (Wald = 49.7; p < 0.001).

CONCLUSION

Our data support early drain removal after pancreatic resection. However, a cut-off of 5000U/L drain amylase on POD1 was associated with a relatively high CR-POPF rate of 7%. A cut-off point of 1000U/L during POD1-3 resulted in 5% CR-POPF and might be a safer alternative.

Yield of staging laparoscopy before treatment of locally advanced pancreatic cancer to detect occult metastases

INTRODUCTION

Locally advanced pancreatic cancer (LAPC) is found in 35% of patients with pancreatic cancer. However, these patients often have occult metastatic disease. Patients with occult metastases are unlikely to benefit from locoregional treatments. This study evaluated the yield of occult metastases during staging laparoscopy in patients with LAPC.

METHODS

Between January 2013 and January 2017 all patients with LAPC underwent a staging laparoscopy after a recent tri-phasic CT-scan of the chest and abdomen. Data were retrospectively reviewed from a prospectively maintained database. Univariate and multivariable logistic regression analysis was conducted to predict metastasis found at laparoscopy.

RESULTS

A total of 91 (41% male, median age 64 years) LAPC patients were included. The median time between CT-scan and staging laparoscopy was 21 days. During staging laparoscopy metastases were found in 17 patients (19%, 95% CI: 12%-28%). Seven (8%) patients had liver-only, 9 (10%) patients peritoneal-only, and 1 (1%) patient both liver and peritoneal metastases. Univariate logistic regression analysis showed that CEA (OR 1.056, 95% CI 1.007-1.107, p = 0.02) was the only preoperative predictor for occult metastases. In a multivariable logistic regression analysis of the preoperative risk factors again only CEA was an independent predictor for occult metastatic disease (p = 0.03). Patients with a CEA above 5 μg/L had a risk of occult metastasis of 91%. FOLFIRINOX was given to 69 (76%) of the patients with a median number of cycles of 8. Subsequent radiotherapy was given to 44 (48%) patients after the FOLFIRINOX treatment. Six (14%) patients underwent a resection after FOLFIRINOX and radiotherapy. The overall 1-year survival was 53% in patients without occult metastasis versus 29% with occult metastasis (p = 0.11). The 1-year OS for patients that completed FOLFIRINOX and radiotherapy was 84%.

CONCLUSION

The yield of staging laparoscopy for occult intrahepatic or peritoneal metastases in patients with locally advanced pancreatic cancer was 19%. Staging laparoscopy is recomended for patients with LAPC for accurate staging to determine optimal treatment.

Effects of bariatric surgery on telomere length and T-cell aging

BACKGROUND

Obesity adversely affects health and is associated with subclinical systemic inflammation and features of accelerated aging, including the T-cell immune system. The presence of metabolic syndrome (MetS) may accelerate, while bariatric surgery might reverse these phenomena. To examine the effects of MetS and bariatric surgery on T-cell aging, we measured relative telomere length (RTL) and T-cell differentiation status in obese patients before and after bariatric surgery.

METHODS

WHO II/III classified obese patients scheduled for bariatric surgery were included: 41 without MetS and 67 with MetS. RTL and T-cell differentiation status were measured in circulating CD4⁺ and CD8⁺ T cells via flow cytometry. T-cell characteristics were compared between patients with and without MetS prior to and at 3, 6, and 12 months after surgery considering effects of age, cytomegalovirus-serostatus, and weight loss.

RESULTS

Thymic output, represented by numbers of CD31-expressing naive T cells, showed an age-related decline in patients with MetS. MetS significantly enhanced CD8⁺ T-cell differentiation. Patients with MetS had significant lower CD4⁺ RTL than patients without MetS. Within the first 6 months after bariatric surgery, RTL increased in CD4⁺ T cells after which it decreased at month 12. A decline in both thymic output and more differentiated T cells was seen following bariatric surgery, more pronounced in the MetS group and showing an association with percentage of body weight loss.

CONCLUSIONS

In obese patients, MetS results in attrition of RTL and accelerated T-cell differentiation. Bariatric surgery temporarily reverses these effects. These data suggest that MetS is a risk factor for accelerated aging of T cells and that MetS should be a more prominent factor in the decision making for eligibility for bariatric surgery.

Nationwide Outcome of Gastrectomy with En-Bloc Partial Pancreatectomy for Gastric Cancer

BACKGROUND

Radical gastrectomy is the cornerstone of the treatment of gastric cancer. For tumors invading the pancreas, en-bloc partial pancreatectomy may be needed for a radical resection. The aim of this study was to evaluate the outcome of gastrectomies with partial pancreatectomy for gastric cancer.

METHODS

Patients who underwent gastrectomy with or without partial pancreatectomy for gastric or gastro-oesophageal junction cancer between 2011 and 2015 were selected from the Dutch Upper GI Cancer Audit (DUCA). Outcomes were resection margin (pR0) and Clavien-Dindo grade ≥ III postoperative complications and survival. The association between partial pancreatectomy and postoperative complications was analyzed with multivariable logistic regression. Overall survival of patients with partial pancreatectomy was estimated using the Kaplan-Meier method.

RESULTS

Of 1966 patients that underwent gastrectomy, 55 patients (2.8%) underwent en-bloc partial pancreatectomy. A pR0 resection was achieved in 45 of 55 patients (82% versus 85% in the group without additional resection, P = 0.82). Clavien-Dindo grade ≥ III complications occurred in 21 of 55 patients (38% versus 17%, P < 0.001). Median overall survival [95% confidence interval] was 15 [6.8-23.2] months. For patients with and without perioperative systemic therapy, median survival was 20 [12.3-27.7] and 10 [5.7-14.3] months, and for patients with pR0 and pR1 resection, it was 20 [11.8-28.3] and 5 [2.4-7.6] months, respectively.

CONCLUSIONS

Gastrectomy with partial pancreatectomy is not only associated with a pR0 resection rate of 82% but also with increased postoperative morbidity. It should only be performed if a pR0 resection is feasible.

Tranexamic acid therapy for postoperative bleeding after bariatric surgery

BACKGROUND

Tranexamic acid reduces blood loss associated with various surgical procedures. Postoperative bleeding caused by dissection or bleeding of the enteric staple lines is a well-known complication following bariatric surgery. Reoperation in order to restore hemostasis is frequently necessary (up to 2.5% in literature). The effect of conservative therapy using tranexamic acid for postoperative hemorrhage after bariatric surgery is still very much a novel technique. The aim is to present our results (reoperation rate and thrombo-embolic complication rate) of tranexamic acid therapy for postoperative bleeding after bariatric surgery in comparison to those in existing literature.

METHODS

We retrospectively reviewed 1388 patients who underwent bariatric surgery (laparoscopic gastric bypass or laparoscopic gastric sleeve). Use of tranexamic acid, reoperation rate, transfusion rate and rate of thrombo-embolic complications were reviewed.

RESULTS

Forty-five of 1388 (3.2%) total patients experienced significant hemorrhage after bariatric surgery. Tranexamic acid was administered in 44 of these patients. A failure of the treatment with tranexamic acid was observed in four patients. The incidence of reoperation was 0.4% for the entire population. No thrombo-embolic complications were registered for patients receiving tranexamic acid.

CONCLUSION

These findings suggest that the administration of tranexamic acid appears to be safe in reducing the reoperation rate for bleeding after bariatric surgery.

Patients' preferences for treatment after neoadjuvant chemoradiotherapy for oesophageal cancer

Background

After neoadjuvant chemoradiotherapy (nCRT) plus surgery for oesophageal cancer, 29 per cent of patients have a pathologically complete response in the resection specimen. Active surveillance after nCRT (instead of standard oesophagectomy) may improve health-related quality of life (HRQoL), but patients need to undergo frequent diagnostic tests and it is unknown whether survival is worse than that after standard oesophagectomy. Factors that influence patients' preferences, and trade-offs that patients are willing to make in their choice between surgery and active surveillance were investigated here.

Methods

A prospective discrete-choice experiment was conducted. Patients with oesophageal cancer completed questionnaires 4–6 weeks after nCRT, before surgery. Patients' preferences were quantified using scenarios based on five aspects: 5-year overall survival, short-term HRQoL, long-term HRQoL, the risk that oesophagectomy is still necessary, and the frequency of clinical examinations using endoscopy and PET–CT. Panel latent class analysis was used.

Results

Some 100 of 104 patients (96·2 per cent) responded. All aspects, except the frequency of clinical examinations, influenced patients' preferences. Five-year overall survival, the chance that oesophagectomy is still necessary and long-term HRQoL were the most important attributes. On average, based on calculation of the indifference point between standard surgery and active surveillance, patients were willing to trade off 16 per cent 5-year overall survival to reduce the risk that oesophagectomy is necessary from 100 per cent (standard surgery) to 35 per cent (active surveillance).

Conclusion

Patients are willing to trade off substantial 5-year survival to achieve a reduction in the risk that oesophagectomy is necessary.

Metal or plastic stents for preoperative biliary drainage in resectable pancreatic cancer

INTRODUCTION

In pancreatic cancer, preoperative biliary drainage (PBD) increases complications compared with surgery without PBD, demonstrated by a recent randomised controlled trial (RCT). This outcome might be related to the plastic endoprosthesis used. Metal stents may reduce the PBD-related complications risk.

METHODS

A prospective multicentre cohort study was performed including patients with obstructive jaundice due to pancreatic cancer, scheduled to undergo PBD before surgery. This cohort was added to the earlier RCT (ISRCTN31939699). The RCT protocol was adhered to, except PBD was performed with a fully covered self-expandable metal stent (FCSEMS). This FCSEMS cohort was compared with the RCT's plastic stent cohort. PBD-related complications were the primary outcome. Three-group comparison of overall complications including early surgery patients was performed.

RESULTS

53 patients underwent PBD with FCSEMS compared with 102 patients treated with plastic stents. Patients' characteristics did not differ. PBD-related complication rates were 24% in the FCSEMS group vs 46% in the plastic stent group (relative risk of plastic stent use 1.9, 95% CI 1.1 to 3.2, p=0.011). Stent-related complications (occlusion and exchange) were 6% vs 31%. Surgical complications did not differ, 40% vs 47%. Overall complication rates for the FCSEMS, plastic stent and early surgery groups were 51% vs 74% vs 39%.

CONCLUSIONS

For PBD in pancreatic cancer, FCSEMS yield a better outcome compared with plastic stents. Although early surgery without PBD remains the treatment of choice, FCSEMS should be preferred over plastic stents whenever PBD is indicated.

TRIAL REGISTRATION NUMBER

Dutch Trial Registry (NTR3142).

Monocyte subsets in blood correlate with obesity related response of macrophages to biomaterials in vitro

Macrophages play a key role in the foreign body response. In this study it was investigated whether obesity affects the acute response of macrophages to biomaterials in vitro and whether this response is associated with biomarkers in blood. CD14 ⁺ monocytes were isolated from blood from obese and age and gender matched lean persons. Monocyte subsets were determined based on CD14 and CD16 on their surface. C-reactive protein (CRP) was measured in peripheral blood. The response of monocyte-derived macrophages to polypropylene (PP), polylactic acid (PLA), polyethylene terephthalate (PET) monofilament, and PET-multifilament (mPET) in culture was based on cytokine production. More IL-6 (for PET), less CCL18 (all materials) and IL-1ra (for PLA) was produced by macrophages from obese patients than lean subjects. Body mass index, serum CRP and to a lesser extend percentages of monocyte subtypes correlated with IL-6, TNFα, CCL18, and IL-1ra production. Taken together, monocyte-derived macrophages of obese patients respond more pro-inflammatory and less anti-inflammatory to biomaterials than macrophages from lean subjects, depending on the material. These results are a step towards personalized medicine for the development of a model or even a blood test to decide which biomaterial might be suitable for each patient.

Comparison of a low Hartmann's procedure with low colorectal anastomosis with and without defunctioning ileostomy after radiotherapy for rectal cancer: results from a national registry

AIM

This study used a national registry to compare the outcome after a low Hartmann's procedure (LHP), defined as removal of most of the rectum to leave a short anorectal stump and an end colostomy, and low anterior resection (LA) with or without a diverting ileostomy (DI) in rectal cancer patients all of whom had received preoperative neoadjuvant radiotherapy (RT).

METHOD

Patients who underwent LHP or LA with or without DI for rectal cancer after RT between 2009 and 2013 were identified from the Dutch Surgical Colorectal Audit. The postoperative outcome was compared between the three groups and risk of complications, reoperation and mortality were analysed in a multivariable model.

RESULTS

The study included 4288 patients were included, of whom 27.8% underwent LHP, 20.2% LA and 52.0% LA with DI. Thirty-day mortality was higher after LHP (3.2% vs 1.3% and 1.3% for LA with or without DI, P < 0.001), but LHP was not an independent predictor of mortality in multivariable analysis. LHP and LA with DI were associated with a lower rate of abdominal infective complications (6.5% and 10.1% vs 16.2%, P < 0.001) and reoperation (7.3% and 8.1% vs 16.5%, P < 0.001). In multivariable analysis, LHP (OR 0.35, 95% CI 0.26-0.47) and LA with DI (OR 0.43, 95% CI 0.33-0.54) were associated with a lower risk of reoperation than LA alone. LHP was associated with a lower risk of any postoperative complication than LA with or without DI (OR 0.81, 95% CI 0.66-0.98).

CONCLUSION

LHP and LA with DI were associated with fewer infective complications and reoperations than LA alone. The rate of any complication was less after LHR than LA with or without DI.

What patients and surgeons should know about the consequences of appendectomy for acute appendicitis after long-term follow-up: factors influencing the incidence of chronic abdominal complaints

INTRODUCTION

Abscess formation and perforation are complications of acute appendicitis that lead to localized or generalized peritonitis. The long-term implications of complicated appendectomy remain largely unknown.

MATERIALS AND METHODS

In the present study, it was investigated whether patients with complicated appendicitis experienced more abdominal complaints after long-term follow-up when compared to uncomplicated cases. In addition, the influence of operation technique (open versus laparoscopic) was studied. A retrospective analysis of 1,481 appendectomies for acute appendicitis was performed in two centers from January 2000 until January 2006. Demographic data, operative reports, intraoperatively adhesions and complications, abdominal pain, and satisfaction were monitored. In total, 1,433 patients were invited to fill out a questionnaire with a median follow-up of 7.1 years. Questionnaires of 526 (37 %) patients were suitable for analysis.

RESULTS

Perforation, abdominal abscesses, or adhesions at initial operation did not result in more abdominal complaints when compared to appendectomy for uncomplicated acute appendicitis. Additionally, no significant differences in abdominal complaints were seen between laparoscopic and open techniques.

CONCLUSION

In conclusion, the results of our study show that after follow-up of 7 years, the incidence of abdominal complaints was not influenced by operative technique or whether acute appendicitis was complicated or not. This finding does not support a causative role for adhesions with regard to chronic abdominal complaints. Our data enables surgeons to inform their patients about the long-term results of appendectomy, whether it was complicated or not.

Long-term survival after perforated diverticulitis

AIM

Short-term survival after emergency surgery for perforated diverticulitis is poor. Less is known about long-term survival. The aims of this study were to evaluate long-term survival after discharge from hospital and to identify factors associated with prognosis.

METHOD

All patients who underwent emergency surgery for perforated diverticulitis in five hospitals in Rotterdam, the Netherlands, between 1990 and 2005, were included. The association between type of surgery (Hartmann's procedure or primary anastomosis) and long-term survival was analysed using multivariate Cox regression analysis, taking into account age American Society of Anesthesiology (ASA) classification, Hinchey score, Mannheim Peritonitis Index (MPI) and surgeon's experience. In addition, survival of the patients was compared with that of the matched general Dutch population.

RESULTS

Of 340 patients included in the study, 250 were discharged alive from hospital. The overall 5-year survival was 53%. Survival was significantly impaired compared with the expected matched gender-, age- and calendar time-specific survival. Overall survival was significantly related to age and ASA classification. Hinchey score, MPI, number of re-interventions, the surgeon's experience and type of procedure did not influence long-term survival, although a trend was found for Hartmann's procedure to be a risk factor for poorer survival compared with primary anastomosis (hazard ratio for mortality: 1.88; 95% confidence interval, 0.96-3.67; P = 0.07).

CONCLUSION

Long-term survival of patients after perforated diverticulitis is limited and mainly caused by the poor general condition of the patients, rather than by the severity of the primary disease or calendar-time and type of procedure.

The use of mesh in acute hernia: frequency and outcome in 99 cases

BACKGROUND

Incarceration of inguinal, umbilical and cicatricial hernias is a frequent problem. However, little is known about the relationship between the use of mesh and outcome after surgery. The goal of this study was to describe the relationship between the use of mesh in incarcerated hernia and the clinical outcome.

PATIENTS AND METHODS

Correspondence, operation reports and patient files between January 1995 and December 2005 of patients presented at one academic and one teaching hospital in Rotterdam were searched for the following keywords: incarceration, strangulation and hernia. The patient characteristics, clinical presentation, pre-operative findings and clinical course were scored and analysed.

RESULTS

A total of 203 patients could be identified: 76 inguinal, 52 umbilical, 39 incisional, 14 epigastric, 14 femoral, five trocar and three spigelian hernias. In the statistical analysis, epigastric, femoral, trocar and spigelian hernias were pooled, due to their small group sizes. One patient was excluded from the analysis because the hernia was not corrected during operation. In total, 99 hernias were repaired using mesh versus 103 primary suture repairs. Twenty-five wound infections were registered (12.3%). One mesh was removed during a reintervention for anastomotic leakage, although no signs of wound infection were present. Nine patients died, none of them due to wound-related problems [one cardiovascular, one ruptured aneurysm, two anastomotic leakage, two sepsis e causa incognita (e.c.i.), three pulmonary complications]. Univariate analysis showed that female patients (P = 0.007), adipose patients (P = 0.016), patients with an umbilical hernia (P = 0.01) and patients who underwent a bowel resection (P = 0.015) had a significantly higher rate of wound infections. The type of repair (e.g. primary suture or mesh), use of antibiotic prophylaxis, gender, ASA class and age showed no significant relation with post-operative wound infection. After logistic regression analysis, only bowel resection (P = 0.020) showed a significant relation with post-operative wound infection.

CONCLUSIONS

Wound infection rates are high after the correction of acute hernia, but clinical consequences are relatively low. Mesh correction of an acute hernia seems to be safe and should be considered in every incarcerated hernia.

Local application of gentamicin collagen implants in the prophylaxis of surgical site infections following gastrointestinal surgery: a review of clinical experience

BACKGROUND

Surgical site infection (SSI) is a common type of healthcare-associated infection in gastrointestinal (GI) surgical procedures, which often has major consequences for patient recovery and increased healthcare costs due to prolonged hospital stay. This article provides an overview of the efficacy and safety of prophylactic application of resorbable gentamicin-containing collagen implants (GCI) in the prevention of SSI following high-risk GI surgical procedures.

METHOD

Nine publications were identified using the PubMed online database and search terms 'gentamicin collagen implant' plus 'surgical site infection', 'wound infection' and 'gastrointestinal surgery'.

RESULTS

Data from 483 patients treated prophylactically have demonstrated that GCI can reduce the wound infection rate in high-risk GI surgical procedures and improve wound healing after pilonidal sinus excision. In a study of 221 patients who underwent colorectal surgery, the wound infection rate was reduced to 5.6% in the GCI group compared to 18.4% in the control group (P < 0.01). GCI also positively influences the post-operative course for patients undergoing particularly risky procedures e.g. abdominoperineal resection (APR) combined with neoadjuvant radiotherapy. In one such patient series, GCI reduced the wound infection rate by over 70% and the length of hospital stay by 40%. Few side effects of GCI were noted in the 9 clinical studies.

CONCLUSIONS

This review demonstrates that GCI can have a positive effect on wound infection rates in high-risk GI surgery and can also improve wound healing after pilonidal sinus excision.

Pathophysiology and prevention of diverticulitis and perforation

OBJECTIVE

This article gives an overview of the current evidence and theories in the pathophysiology of diverticulosis, diverticulitis and perforation and discusses its prevention.

BACKGROUND

Diverticular disease is one of the most common diseases related to the gastrointestinal tract in Western countries. The pathogenesis of this disease process is probably multifactorial, but remains poorly understood and inadequately investigated.

METHODS

A literature search was performed in order to give an overview of the current evidence and theories in the pathophysiology of diverticula formation and the factors related to progression towards inflammation and even perforation. Strategies for prevention of (perforated) diverticulitis are also discussed.

RESULTS/CONCLUSION

The pathogenesis of diverticular disease and its complications seems to be a result of a complex interaction between exposure to a low-fibre diet, possible genetic influences, the coexistence of other bowel diseases and the impact of medicine use. This eventually leads to alterations in colonic pressures and motility and structural changes of the colon wall. Unfortunately the evidence is frequently conflicting in the present literature or lacking altogether.

The impact of chronic smoking on rectal mucosal blood flow

BACKGROUND

Chronic smoking adversely affects peripheral vasculature. The aim of the present study was to investigate the effect of chronic cigarette smoking on rectal microvascular blood flow.

METHODS

Rectal mucosal blood flow (MBF) was measured in 80 subjects (44 smokers and 36 non-smokers). The MBF was measured in the four quadrants of the rectum by laser Doppler flowmetry.

RESULTS

Rectal perfusion was found to be significantly lower in posterior midline compared to the other sites. In chronic smokers the observed MBF measured at the posterior and ventral sites was significantly lower compared to non-smokers (P = 0.04 and P = 0.03, respectively).

CONCLUSIONS

Our results suggest that rectal mucosal blood flow is reduced in chronic smokers.

Restoration of bowel continuity after surgery for acute perforated diverticulitis: should Hartmann's procedure be considered a one-stage procedure?

OBJECTIVE

Hartmann's procedure (HP) still remains the most frequently performed procedure in acute perforated diverticulitis, but it results in a end colostomy. Primary anastomosis (PA) with or without defunctioning loop ileostomy (DI) seems a good alternative. The aim of this study was to assess differences in the rate of stomal reversal after HP and PA with DI and to evaluate factors associated with postreversal morbidity in patients operated for acute perforated diverticulitis.

METHOD

All 158 patients who had survived emergency surgery for acute perforated diverticulitis in five teaching hospitals in The Netherlands between 1995 and 2005 and underwent HP or PA with DI were retrospectively studied. Age, gender, ASA-classification, severity of primary disease, delay of stoma reversal, surgeon's experience, surgical procedure and type of anastomosis were analysed in relation to outcome after stoma reversal.

RESULTS

Of the 158 patients, 139 had undergone HP and 19 PA with DI. The reversal-rate was higher in patients with DI (14/19; 74%) compared to HP (63/139; 45%) (P = 0.027) Delay between primary surgery and stoma reversal was shorter after PA with DI compared with HP (3.9 vs 9.1 months; P < 0.001). Cumulative postreversal morbidity after HP was 44%. Early surgical complications occurred in 22 of 63 patients. Morbidity after DI reversal was 15% (P < 0.001). Three patients died after HP reversal, none died after DI reversal. Anastomotic leakage was observed in 10 patients after HP reversal. This was less frequently observed when the operation was performed by a specialist colorectal surgeon (10%vs 33%; P = 0.049) and when a stapled anastomosis was performed (4%vs 24%; P = 0.037).

CONCLUSIONS

Reversal of HP should only be performed by an experienced colorectal surgeon, preferably performing a stapled anastomosis, or probably not be performed at all, as it is accompanied by high postoperative morbidity and even mortality. It is important that these findings are taken in account for when performing primary emergency surgery for acute perforated diverticulitis.

COLOR II. A randomized clinical trial comparing laparoscopic and open surgery for rectal cancer

INTRODUCTION

Laparoscopic resection of rectal cancer has been proven efficacious but morbidity and oncological outcome need to be investigated in a randomized clinical trial.

TRIAL DESIGN

Non-inferiority randomized clinical trial.

METHODS

The COLOR II trial is an ongoing international randomized clinical trial. Currently 27 hospitals from Europe, South Korea and Canada are including patients. The primary endpoint is loco-regional recurrence rate three years post-operatively. Secondary endpoints cover quality of life, overall and disease free survival, post-operative morbidity and health economy analysis.

RESULTS

By July 2008, 27 hospitals from the Netherlands, Belgium, Germany, Sweden, Spain, Denmark, South Korea and Canada had included 739 patients. The intra-operative conversion rate in the laparoscopic group was 17%. Distribution of age, location of the tumor and radiotherapy were equal in both treatment groups. Most tumors are located in the mid-rectum (41%).

CONCLUSION

Laparoscopic surgery in the treatment of rectal cancer is feasible. The results and safety of laparoscopic surgery in the treatment of rectal cancer remain unknown, but are subject of interim analysis within the COLOR II trial. Completion of inclusion is expected by the end of 2009.

TRIAL REGISTRATION

Clinicaltrials.gov, identifier: NCT00297791 (www.clinicaltrials.gov).

Anterolateral rectopexy for correction of rectoceles leads to good anatomical but poor functional results

BACKGROUND

Several different surgical repair procedures for symptomatic rectocele have been described with variable results. In our clinic, a modified anterolateral rectopexy is used. In this article we evaluate our results, with emphasis on patient satisfaction.

METHODS

From 2001 until 2003, twenty patients with a symptomatic rectocele were treated by anterolateral rectopexy. The preoperative dynamic defecogram and anorectal complaints were analyzed and compared to postoperative outcome via a standardized questionnaire.

RESULTS

After surgery, all rectoceles were restored as shown by postoperative defecogram. Anorectal symptoms (incomplete evacuation, continuous urge, prolapse, digital evacuation) were improved in 40%. As new-onset symptoms, dyspareunia (50%), digital support (55%) and incomplete evacuation (75%) were mentioned frequently. Most of the patients with larger rectoceles (>3.5 cm) had increased anorectal complaints after surgery.

CONCLUSIONS

Anterolateral rectopexy for treatment of rectocele give limited improvement of anorectal complaints. Besides, many patients developed new complaints postoperatively and hence overall satisfaction was low.

Is less more? A prospective trial on one trocar appendectomy

One trocar appendectomy is a combination of laparoscopic and open appendectomy. The advantage, along with improved cosmesis, is the possibility to introduce a dissection instrument through the optical trocar without an additional incision. In this prospective study the sense of one trocar appendectomy is evaluated in daily practise for a cohort of consecutive patients with suspected acute appendicitis. Twenty-two patients were enrolled. One-trocar appendectomy was successful in 13 patients. In 8 patients one extra 2, 5 or 10 millimetre trocar was necessary. In one patient a third trocar was necessary. Conversion to an open appendectomy through a grid iron incision was not necessary. The pathologist confirmed the diagnosis of acute appendicitis in all patients. The average operation time was 53 minutes. Complications included one wound abscess and one wound haematoma. In conclusion one trocar appendectomy is a good and safe technique in patients with the suspicion of acute appendicitis, provided that the operative team must be experienced in laparoscopic surgery and the constitution of the patient is suitable for this technique.

Vascular anatomy of the stomach related to gastric tube construction

In view of constructing a gastric tube after esophagus resection, the vascular anatomy of the greater curvature of the stomach, especially the connection between the left and right gastro-epiploic arteries, was investigated. The vascular anatomy was studied in 20 embalmed human specimens. After dissection a gastric tube of 4 cm wide was constructed, using the greater gastric curvature. Various lengths of the arterial arcades were measured. In 70% an anastomosis between the right and left gastro-epiploic arteries was present. With the construction of an isoperistaltic gastric tube, in which the left gastro-epiploic artery is left in situ (ligating it at the splenic hilus), there is an 18.7% increase of length of arterial arcade along the gastric tube. Leaving the left gastro-epiploic artery in situ increases the feeding arterial arcaded-length along the gastric tube with 5.0 cm (19%).

[Probiotic prophylaxis in patients with predicted severe acute pancreatitis: a randomised, double-blind, placebo-controlled trial]

OBJECTIVE

To evaluate whether enteral prophylaxis with probiotics in patients with predicted severe acute pancreatitis prevents infectious complications.

DESIGN

Multicentre, randomised, double-blind, placebo-controlled trial.

METHOD

A total of 296 patients with predicted severe acute pancreatitis (APACHE II score > or = 8, Imrie score > or = 3 or C-reactive protein concentration > 150 mg/l) were included and randomised to one of two groups. Within 72 hours after symptom onset, patients received a multispecies preparation of probiotics or placebo given twice daily via a jejunal catheter for 28 days. The primary endpoint was the occurrence of one of the following infections during admission and go-day follow-up: infected pancreatic necrosis, bacteraemia, pneumonia, urosepsis or infected ascites. Secondary endpoints were mortality and adverse reactions. The study registration number is ISRCTN38327949.

RESULTS

Treatment groups were similar at baseline with regard to patient characteristics and disease severity. Infections occurred in 30% of patients in the probiotics group (46 of 152 patients) and 28% of those in the placebo group (41 of 144 patients; relative risk (RR): 1.1; 95% CI: 0.8-1.5). The mortality rate was 16% in the probiotics group (24 of 152 patients) and 6% (9 of 144 patients) in the placebo group (RR: 2.5; 95% CI: 1.2-5.3). In the probiotics group, 9 patients developed bowel ischaemia (of whom 8 patients died), compared with none in the placebo group (p = 0.004).

CONCLUSION

In patients with predicted severe acute pancreatitis, use of this combination of probiotic strains did not reduce the risk of infections. Probiotic prophylaxis was associated with a more than two-fold increase in mortality and should therefore not be administered in this category of patients.

Introduction of preoperative radiotherapy in the treatment of operable rectal cancer in the Southwest region of the Netherlands

INTRODUCTION

After publication of the results of the Dutch TME-trial preoperative radiotherapy followed by TME-surgery was introduced in July 2001 in the region of the comprehensive cancer centre Rotterdam as standard treatment for rectal cancer. The aim of this study is to identify the compliance to a new standardized treatment protocol i.e. the introduction of preoperative radiotherapy and to analyze the results of rectal cancer treatment in the Cancer Centre Rotterdam Region.

PATIENTS AND METHODS

A total of 521 patients with adenocarcinoma of the rectum were included in the period from 2001 to 2003. All patients were treated with curative intent.

RESULTS

There was a significant increase of preoperative radiotherapy for patients with a tumour in the lower two-third of the rectum (21% versus 69%, p<0.001). Peri-operative mortality rate was 2.7% and overall anastomotic leakage rate was 10.3%. There was a significant increase in the occurrence of anastomotic leakage in end-to-end anastomoses (p<0.0001). Most anastomotic leakages occurred when patients were operated in between 4 and 8 days after the end of radiotherapy. Several aspects such as continence for urine and faeces and sexual functions were poorly registered. The total number of lymph nodes registered in pathology reports was low. The rate of reported circumferential margins increased from 37% to 70% after feedback to the regional pathology working group.

CONCLUSION

The regional quality of rectal cancer surgery is conform preset quality-demands. There was a significant increase in the percentage preoperative radiotherapy, but still about 25% of patients who qualified for radiotherapy did not receive radiation. Pathology reports improved during registration, which illustrates the importance of registration to assess and improve quality of rectal cancer treatment.

Primary closure of the skin after stoma closure. Management of wound infections is easy without (long-term) complications

BACKGROUND AND AIMS

Whether or not the skin can be closed primarily after stoma closure is still debated in the existing literature. Therefore, this present study was undertaken to compare the complications and consequences between primary or delayed closure of the skin after stoma closure.

PATIENTS AND METHODS

All consecutive stoma closures between January 2001 and August 2004 were included. In 25 patients (group I), the skin at the stoma site was closed primarily. In 37 patients (group II), the skin was left open. Patient characteristics, comorbidity, medication use, hospital stay and long-term complications were recorded and retrospectively compared between the two groups.

RESULTS

In group I, wound infection rate was 36% versus 5% in group II (p = 0.005). Infected wounds were mostly found after ileostomy closure with primary closure of the skin (p = 0.018). The occurrence of a wound infection was not related to the use of corticosteroids, diabetes mellitus, fistula formation, anastomotic leakage, or primary disease and did not lead to a prolonged hospital stay or an increased number of incisional hernias. conclusion: In our opinion, it is safe to close the skin after stoma closure, but patients should be informed carefully about the advantages and disadvantages of this strategy, especially in case of ileostomy closure.

Revision of gastrointestinal mesenchymal tumours with CD117

BACKGROUND

Tyrosinekinase inhibitors improve the treatment of gastrointestinal stromal tumours (GISTs) and their diagnosis has been facilitated by recently developed immunohistochemical markers. It is hypothesised that in the past, the true incidence of GISTs has been underestimated.

AIMS

To study the clinicopathological features of previously resected mesenchymal tumours of the gastrointestinal tract and determine the accuracy of previous diagnostic results.

PATIENTS AND METHODS

Patients with mesenchymal tumours of the gastrointestinal tract operated on between 1987 and 2002 were identified using medical and pathologic files. Immunohistochemical staining for CD117, CD34, desmin and S100 was performed, and diagnosis reviewed.

RESULTS

Thirty-six mesenchymal tumours were reanalysed. Before revision, diagnosis of GIST was correctly made in only six cases. Supportive use of immunohistochemical markers for accurate diagnosis of the remaining 30 previously undefined mesenchymal tumours yielded 17 additional GISTs. Therefore, 23 of 36 (63%) gastrointestinal mesenchymal tumours were shown to be GISTs.

CONCLUSIONS

The true incidence of GISTs has been underestimated. There is merit in reviewing the clinical diagnoses of all mesenchymal tumours of the gastrointestinal tract with modern immunohistochemical markers. This may enhance clinical decision making.

The value of plasma markers for the clinical behaviour of phaeochromocytomas

OBJECTIVE

Phaeochromocytomas (PCCs) are widely known for their clinical unpredictability. This study intends to define predictive plasma markers for their variable postoperative behaviour. Furthermore, the diagnostic accuracy of these plasma tests was determined.

DESIGN AND METHODS

A retrospective correlative study was performed in a series of 83 operated and four autopsied patients in order to correlate preoperative catecholamine (CAT) levels of 103 PCCs with their clinical behaviour. In a subset of cases, chromogranin-A (Chr-A) and enzymes/precursors of the CAT biosynthesis were studied for their predictive value.

RESULTS

Basal CAT levels were elevated in 81/87 instances (sensitivity: 93%). Four of six cases with normal measurements showed only medullary hyperplasia. Larger PCCs, particularly those showing necrosis, capsular and vascular invasion, secreted higher CAT levels. Bilateral, hereditary tumours were less productive than their unilateral counterparts. Extra-adrenal PCCs secreted significantly lower levels of epinephrine (EPI) than intra-adrenal tumours. Fourteen patients developed metastases. According to Kaplan-Meier estimations, patients with higher levels of dopamine, norepinephrine (NE) and aromatic l-amino acid decarboxylase as well as lower ratios of EPI/EPI+NE, had significantly shorter metastases-free intervals. Existence of preoperative hypertension, left ventricular hypertrophy and measured blood pressures showed significant positive relationships with CAT levels, but not with Chr-A.

CONCLUSIONS

These data showed that plasma CAT measurement is a sensitive method in the diagnostic work-up of PCCs. Those tumours producing normal levels are commonly small and asymptomatic. Furthermore, certain secretion patterns are indicative of the presence of metastases as well as the size and site of sporadic and syndrome-related PCCs.

[(123)I]metaiodobenzylguanidine and [(111)In]octreotide uptake in begnign and malignant pheochromocytomas

Selecting the appropriate approach for resection and follow-up of pheochromocytomas (PCCs) is highly dependent upon reliable localization and exclusion of multifocal, bilateral, or metastatic disease. Metaiodobenzylguanidine (MIBG) scintigraphy was developed for functional localization of catecholamine-secreting tissues. Somatostatin receptor imaging (SRI) has a high sensitivity for localizing head and neck paragangliomas, but studies of intraabdominal PCCs are rare. In this study we review our experience of [(123)I]MIBG and SRI, performed since 1983 and 1989, respectively, in the work-up of primary and recurrent PCCs. Scintigraphic results were correlated with catecholamine secretion, size and site, malignancy, associated tumor syndromes, and morphological features. [(123)I]MIBG scans were performed in a total of 75 patients, in 70 cases before resection of primary PCCs and in 5 cases because of recurrent disease. Ninety-one PCCs were resected. The overall detection rates were 83.3% and 89.8% for PCCs larger than 1.0 cm. Multifocal disease was detected in 4 patients with [(123)I]MIBG. [(123)I]MIBG uptake correlated with greater size of PCC (r = 0.33; P = 0.008) and greater concentration of plasma epinephrine (r = 0.32; P = 0.006). [(123)I]MIBG-negative PCCs (n = 14) had significantly (P = 0.01) smaller diameters than [(123I)]MIBG-positive tumors. Furthermore, [(123)I]MIBG uptake was significantly higher in unilateral (P = 0.02), benign (P = 0.02), sporadic (P = 0.02), intraadrenal (P = 0.02), and capsular invasive (P = 0.03) PCCs than in bilateral, malignant, MEN2A/2B-related, extraadrenal, and noninvasive PCCs, respectively. The detection rate of SRI was only 25% (8 of 32) for primary benign PCCs. In 14 patients metastases occurred, which were effectively visualized with [(123)I]MIBG in 8 of 14 cases. SRI was able to detect metastases in 7 of 8 cases, including 3 [(123)I]MIBG-negative metastatic cases. In addition, [(123)I]MIBG and SRI detected 2 recurrences. In conclusion, [(123)I]MIBG uptake is correlated with the size, epinephrine production, and site of PCCs. Its role in bilateral and MEN2A/2B-related PCCs seems limited. In cases of recurrent elevation of catecholamines, localization of metastases and/or recurrence should be attempted with [(123)I]MIBG scintigraphy. In suspicious metastatic PCCs, SRI might be considered to supplement [(123)I]MIBG scintigraphy.

The difficult diagnostic approach of the intraperitoneal mesothelioma

The malignant mesothelioma is a rare tumour with a rising incidence during the past decades [Lancet 1 (1986) 1275; Br J Int Med 28 (1971) 59; Am J Int Med 9 (1986) 397]. The tumour is derived from the mesothelial lining of the pleural cavity, the pericardium or the peritoneum. Mesotheliomas solely involving the peritoneum are particularly rare. Two cases of malignant peritoneal mesotheliomas are described to demonstrate the difficulties in diagnosing this disease. Surgical exploration, either by laparotomy, or preferably by laparoscopy, has been proven valuable as a diagnostic method.

RET is expressed but not mutated in extra-adrenal paragangliomas

This study has investigated the role of the RET proto-oncogene, which has been identified as the susceptibility gene for multiple endocrine neoplasia (MEN) type 2, in the development of sporadic and familial extra-adrenal paragangliomas. RET protein expression was analysed by immunohistochemistry. Subsequently, DNA extracted from 52 tumours of 44 patients was screened for somatic RET point mutations in exons 10, 11, and 13-16, where oncogenic mutations have recently been described in a subset of sporadic medullary thyroid carcinomas and phaeochromocytomas. The methods employed included non-isotopic polymerase chain reaction-based single strand conformation polymorphism (PCR-SSCP) analysis and heteroduplex gel electrophoresis, followed by direct sequencing of PCR products. RET protein expression was demonstrated in all ten paragangliomas tested. However, none of the familial or sporadic extra-adrenal paragangliomas contained somatic mutations in exons 10, 11, or 13-16 of the RET proto-oncogene, whereas control samples with known mutations in these exons exhibited the expected band shift, or yielded an additional band with retarded migration. Although paragangliomas exhibit RET protein expression, these data indicate that oncogenic RET proto-oncogene mutations do not appear to be generally important in the formation of sporadic paragangliomas.

Proliferative index in phaeochromocytomas: does it predict the occurrence of metastases?

Evaluation of the malignant potential of phaeochromocytomas in the absence of metastases presents a formidable challenge to both clinicians and pathologists. Until now, no widely accepted clinical, histological, immunohistochemical or molecular method has become available to discriminate malignant from benign phaeochromocytomas. In other endocrine tumours, estimation of proliferative activity by MIB-1 immunostaining has emerged as a promising approach for the determination of metastatic potential. In this study, the utility of MIB-1 immunostaining as a predictive marker for the occurrence of metastases in phaeochromocytomas was evaluated. In addition, the density of S100-positive sustentacular cells was studied, since their depletion has been identified as a negative predictive marker in smaller series. Furthermore, several clinicopathological parameters were evaluated. One hundred and ten patients operated on for a total of 99 benign and 37 malignant phaeochromocytomas were studied. All malignant tumours had documented metastases. The histopathological diagnosis of primary tumours and metastases was reviewed and graded for angioinvasion, capsular extension, and intra-tumoural necrosis. The proliferative index (percentage of MIB-1-positive cells) and the density of S100-positive cells were assessed. In addition, age at resection, associated familial tumour syndromes, tumour size, and tumour location were recorded. Univariate analysis revealed statistically significant correlations between malignancy and proliferative index (p<0.0005) and depletion of S100-positive sustentacular cells (p<0.0005). Fifty per cent of the malignant, but none of the benign phaeochromocytomas had a proliferative index greater than 2.5%. Higher age at resection (p=0. 03), sporadic occurrence (p<0.0005), extra-adrenal location (p<0. 0005), tumour size (p<0.0005), and necrosis (p=0.03) were also significantly associated with malignancy. Logistic regression showed that proliferative index (p=0.0072), size (p=0.0022), and extra-adrenal location (p=0.0012) of the primary tumour were independently predictive for malignancy. In conclusion, this study indicates that assessing the proliferative activity of phaeochromocytomas by MIB-1 immunohistochemistry can predict the occurrence of metastases. The predictive value of S100 immunostaining, tumour size, and extra-adrenal location of the tumour was also confirmed.

Prognostic value of p53, bcl-2, and c-erbB-2 protein expression in phaeochromocytomas

Many studies have tried to discriminate malignant from benign phaeochromocytomas, but until now no widely accepted histological, immunohistochemical, or molecular methods have been available. In this study of 29 malignant and 85 benign phaeochromocytomas from 102 patients, immunohistochemistry was performed with antibodies to the tumour suppressor gene product p53 and the proto-oncogene products bcl-2 and c-erbB-2, using the avidin-biotin complex method. Malignant phaeochromocytomas showed a statistically significant higher frequency of p53 (p=0.042) and bcl-2 (p=0.037) protein expression than their benign counterparts. The combination of both markers showed an even higher significance (p=0.004), to which both markers contributed equally. Overexpression of c-erbB-2 was associated with the occurrence of familial phaeochromocytomas (p=0. 001), but no difference was found between benign and malignant cases. In conclusion, p53, bcl-2, and c-erbB-2 all appear to be involved in the pathogenesis of a proportion of phaeochromocytomas. Immunoreactivity to p53 and bcl-2 proteins may help to predict the clinical behaviour of phaeochromocytomas.

Retroperitoneal adrenalectomy: open or endoscopic?

Conventional adrenalectomy requires relatively large incisions. To assess the value of retroperitoneal endoscopic adrenalectomy, a case-control study was performed comparing the endoscopic technique to conventional posterior adrenalectomy. All patients had adrenal tumors less than 7 cm in diameter. Endoscopic retroperitoneal adrenalectomy required more operative time (90 vs. 60 minutes, p < 0.0001) than the open approach but was associated with less blood loss (20 vs. 125 ml, p < 0.0001). Endoscopic adrenalectomy caused less pain postoperatively (p = 0.0005) and was associated with fewer complications (p = 0.035). The hospital stay was shorter after endoscopic adrenalectomy than after open adrenalectomy (p < 0.0001). In conclusion, we advocate endoscopic retroperitoneal adrenalectomy in patients with small adrenal tumors.

Prognostic value of RET proto-oncogene point mutations in malignant and benign, sporadic phaeochromocytomas

Somatic mutations in the RET proto-oncogene are involved in the pathogenesis of an important subset (40-60%) of sporadic medullary thyroid carcinomas (MTCs) and less frequently (0-31%) in benign, sporadic phaeochromocytomas. Since limited data exist regarding the significance of somatic RET mutations in malignant phaeochromocytomas, we analysed a multicentre series of proven malignant (i.e., metastasised) phaeochromocytomas. Analogous with MTCs, where RET mutations lead to an aggressive behaviour, we hypothesised that somatic mutations would occur more frequently in malignant than in benign phaeochromocytomas. Paraffin-embedded tissue was available from 29 malignant and 27 benign phaeochromocytomas. Exons 10, 11 and 16 were analysed by non-radioactive single-strand conformation polymorphism, heteroduplex gel electrophoresis, restriction enzyme digestion and aberrant band patterns by non-isotopic sequencing. In only 1 of 29 malignant phaeochromocytomas was a mis-sense mutation found (at codon 634 of exon 11), whereas in 15% (4/27) of the benign tumours a point mutation was detected (in 3 tumours in exon 16 at codon 918 and in 1 tumour in exon 10 at codon 618). Absence of these mutations in non-tumourous DNA proved their somatic origin. Contrary to what has been reported for MTCs, oncogenic RET mutations are not associated with an aggressive tumour behaviour in sporadic phaeochromocytomas.

Germline mutations in the vhl gene in patients presenting with phaeochromocytomas

It has been shown that an appreciable percentage of patients presenting with primary, apparently sporadic phaeochromocytomas may in fact have von-Hippel-Lindau (VHL) disease. In order to investigate this, we retrospectively screened 68 patients, who had been operated on for phaeochromocytomas, for the presence of germline mutations in the vhl gene. DNA was isolated from peripheral-blood leukocytes and used to screen the entire coding sequence and the intron-exon boundaries of the vhl gene for mutations, using a PCR-based SSCP strategy. When an abnormal pattern was found in the SSCP analysis, sequence analysis was carried out. We found SSC variants in the vhl gene in 8 of the 68 patients. Of 6 patients, 2 turned out to be related (an uncle and his nephew), and they carried the same mis-sense mutation: R64P. In 4 other patients, mis-sense mutations, P25L, L63P, G144Q and I147T, were also identified. None of these mutations has been described, and 3 of them (P25L, L63P and R64P) are located closer to the N terminus of the vhl protein than any reported vhl mutation. In the remaining 2 cases, the mutations were localized not in the coding sequence but in the intronic sequence (but not within splice-sites), adjacent to the exon, so they were probably not related to the disease. Our results show that a relatively high proportion (6/68, or 8.8%), though not as high as the 20% reported earlier, of patients with apparently sporadic phaeochromocytomas may carry germline mutations in the vhl gene.

Single radionuclide scintigraphy with 99mtechnetium-sestamibi and ultrasonography in hyperparathyroidism

OBJECTIVE

Assessment of 99mTechnetium-sestamibi scintigraphy and ultrasonography as methods of locating enlarged parathyroid glands before operation.

DESIGN

Retrospective analysis.

SETTING

University hospital, The Netherlands.

SUBJECTS

21 patients with primary hyperparathyroidism and 6 patients with persistent or recurrent hyperparathyroidism.

INTERVENTIONS

Single radionuclide scintigraphy with 99mTc-sestamibi, ultrasonography of the neck, and parathyroidectomy.

MAIN OUTCOME MEASURES

Operative findings, postoperative serum calcium concentrations.

RESULTS

99mTc-sestamibi scintigraphy correctly identified 17 of 21 parathyroid tumours in patients who were about to undergo their first parathyroidectomy (sensitivity = 81%) with a positive predictive value of 94% and all 6 in patients with persistent or recurrent hyperparathyroidism. Ultrasonography correctly identified 13 parathyroid tumours in 18 patients about to undergo their first parathyroidectomy (sensitivity = 72%) with a positive predictive value of 93%, but only 3 among the 6 patients with persistent or recurrent hyperparathyroidism.

CONCLUSION

Single radionuclide scintigraphy with 99mTc-sestamibi seems to identify the sites of parathyroid tumours accurately in patients with persistent or recurrent hyperparathyroidism but is not recommended for patients with primary hyperparathyroidism. Combining scintigraphy with ultrasonography does not improve the accuracy.

[Preoperative noninvasive tests for localization of enlarged parathyroid glands in 115 patients with hyperparathyroidism]

OBJECTIVE

To evaluate results of preoperative localisation techniques in patients operated for hyperparathyroidism (HPT).

SETTING

Rotterdam University Hospital.

DESIGN

Retrospective study.

METHOD

Results of 4 non-invasive preoperative localisation techniques in 115 patients with HPT were compared with operative findings of 116 explorations. Sensitivity and specificity were calculated for single versus multiple gland disease, primary exploration versus re-explorations and anatomical versus ectopic localisation.

RESULTS

Sensitivity of preoperative ultrasound, thallium-technetium subtraction scintigraphy, computed tomography and 99mTc-sestamibi (MIBI) scanning in patients with single gland disease was 56%, 65%, 67% and 83% respectively. In multiple gland disease preoperative localisation techniques were much less successful. For MIBI scintiscanning this question remains unanswered. Specificity of all techniques was high. Success rates of preoperative localisation studies for primary operations and re-explorations were similar. Mean weight of parathyroid tumours that were missed preoperatively was lower than of successfully localised tumours. Only computed tomography and thallium-technetium scintigraphy were able to localise retrosternal parathyroid tumours.

CONCLUSION

Review of the literature reveals that there is additional benefit of the preoperative localisation studies in re-exploration for HPT, in contrast to primary exploration. By combining localisation techniques more tumours are visualised. Preliminary results of MIBI scanning are favourable.

Peritoneal mesothelioma without ascites formation

A case of malignant peritoneal mesothelioma without development of ascites is described. The patient had a 1-year history of non-specific symptoms preceding this diagnosis. The insidious onset of clinical signs, the diagnostic procedures, and the pathologic findings are discussed.

Surgical implications of drug-induced rhabdomyolysis

Four cases are described of acute non-traumatic rhabdomyolysis with subsequent development of a compartmental syndrome, requiring extensive fasciotomies. All the patients were young male alcoholics who were taking benzodiazepines as part of an addiction treatment programme. In this risk group clinicians should be aware of two serious complications of non-traumatic rhabdomyolysis: acute renal failure and compartmental syndrome.