Kevin Wevers

LAPAROSCOPIC CHOLECYSTECTOMY IN ACUTE CHOLECYSTITIS: C-REACTIVE PROTEIN LEVEL COMBINED WITH AGE PREDICTS CONVERSION

Introduction: The aim was to enable prediction of risk for conversion in early laparoscopic cholecystectomy for acute cholecystitis. Methods: Multivariate analysis and receiver operating characteristic curve analysis were used to define independent predictors for conversion and optimal cutoffs. Using those, a scoring system was created to predict conversion. Results: In 261 patients, conversion to open cholecystectomy was necessary in 62 cases (24%). Multivariate analysis revealed age and C-reactive protein (CRP) level to be independent predictors for conversion (odds ratio 1.02; P=0.02 and odds ratio 1.01; P<0.001). Using cutoffs obtained by receiver operating characteristic curve analysis resulted in an useful scoring system to predict conversion risk (age>65 y=1+CRP value>165 mg/L=1): score 0=12%, 1=29%, 2=67% (P<0.001). Conclusions: Higher age and elevated CRP level are independent predictors for conversion. Surgery for acute cholecystitis in patients with age >65 years and/or CRP level >165 mg/L should be considered as high risk for conversion.

Reoperation after colorectal surgery is an independent predictor of the 1-year mortality rate.

BACKGROUND: Comparative evaluation of surgical quality among hospitals must improve outcome and efficiency, and reduce medical costs. Reoperation after colorectal surgery is a consequence of surgical complications and therefore considered a quality-of-care indicator. With respect to the mortality rate, the 1-year mortality may be a more meaningful figure than in-hospital mortality, because it also reflects the impact of surgical complications beyond discharge. OBJECTIVE: The aim of our study was to evaluate the 1-year mortality after colorectal surgery and to identify predicting factors. DESIGN: This study was a retrospective analysis from our colorectal surgery database. PATIENTS: All patients who underwent elective colorectal surgery from 2005 to 2008 were included. MAIN OUTCOME MEASURES: Both univariate and multivariate analysis were performed to identify predicting factors. The following variables were analyzed: age, operative risk according to the ASA class, Charlson-Age Comorbidity Index, indication for and type of resection, primary anastomosis, tumor staging, anastomotic leakage, and reoperation. RESULTS: For 743 consecutive patients, the 1-year mortality rate was 6.9%. Patients were operated on mainly because of colorectal cancer (n = 537; 72%). The rate of reoperation and in-hospital mortality was 12.8% and 2.4%. Univariate survival analysis demonstrated that ASA class, age, Charlson-Age Comorbidity Index, reoperation, and stage of disease were independent predictors of 1-year mortality. Multivariate analysis showed that ASA class (P = .020; HR 1.69), age (P = .015; HR 2.08) and reoperation (P = .001; HR 2.72) are directly correlated with 1-year mortality. LIMITATIONS: Both patients with benign diseases and colorectal cancer are included. Furthermore, no clear guidelines on whether to perform a reoperation were available. CONCLUSION: One-year mortality after colorectal surgery is independently predicted by ASA class, age, and reoperation. Our results underline the value of the 1-year mortality rate and the reoperation rate as parameters for quality assessment in colorectal surgery.

Assessment of a new scoring system for predicting non-sentinel node positivity in sentinel node-positive melanoma patients

BACKGROUND When completion lymph node dissection (CLND) is performed in sentinel node (SN)-positive melanoma patients, a positive non-sentinel node (NSN) is found in approximately 20% of them. Recently, Murali et al. proposed a new scoring system (non-sentinel node risk score, N-SNORE) to predict the risk of NSN positivity in SN-positive patients. The objectives of the current study were to identify factors predicting NSN positivity and to assess the validity of the N-SNORE in an independent patient cohort. METHODS All SN-positive patients who underwent CLND at a single institution between 1995 and 2010 were analyzed. Characteristics of the patient, primary melanoma, and SN(s) were tested for association with NSN positivity. Missing values were reconstructed using multiple imputation to enable multivariable analysis. RESULTS CLND revealed positive NSNs in 30 (23%) of 130 SN-positive patients. Primary melanoma regression (p = 0.03) was independently associated with NSN positivity. After adjustment because of missing data on perinodal lymphatic invasion, N-SNORE proved to be a significant stratification model in our patient cohort (p = 0.003): 5.9% NSN positivity in the very low risk category and 75.0% NSN positivity in the very high risk category. CONCLUSIONS Presence of regression in the primary melanoma was independently associated with a higher risk of NSN positivity. The slightly modified N-SNORE scoring system provided useful stratification of the risk for NSN positivity. However, lack of perinodal lymphatic invasion data may have reduced its predictive value.

Geographical distribution of publications in the scientific field of surgical oncology.

Treatment of solid tumors consists of a multi‐disciplinary approach with surgical resection as the cornerstone of treatment for many cancer types. Improvement in the surgical outcome of cancer can only be achieved with the development of new combined, evidence based treatment strategies. Scientific research in the field of surgical oncology is important for the expansion of knowledge and for the improvement of multimodality cancer treatment. The amount of effort spend by researchers to study cancer and the financial investment brought up by governmental and private sector sources, has been accumulating worldwide. Obviously, the scientific contribution to the field of surgical oncology is not equal for each country, since different countries hold different healthcare systems, financial research sources and scientific research programs. In order to obtain insight in the distribution between the scientific contributions of countries, rankings have been made through Journal Citation Reports for universities and different fields of medicine [1]. Ranking of countries according their scientific literature contribution has been performed for anesthesia and critical care medicine, pathology, ophthalmology, respiratory medicine, dermatology, radiology, gynecology, oncology, orthopedic surgery, and general surgery but the field of surgical oncology is lacking. For this article an international ranking for the field of surgical oncology was made based on the geographical distribution of publications in this field. All peer‐reviewed journals with an impact factor above 1.0, both assigned to the “oncology” and the “surgery” category according the 2012 journal citation reports established by the Institute for Scientific Information, were included [1]. The six selected journals were: Annals of Surgical Oncology, European Journal of Surgical Oncology, Surgical Oncology, Journal of Surgical Oncology, Surgical Oncology Clinics of North America, and World Journal of Surgical Oncology. All articles with an abstract in the PubMed NCBI journal database [2] were registered by country of origin over a 10‐year period (2001–2010) and ranked according five categories: mean impact factor, number of publications per 10 inhabitants [3], number of publications per annual number of new cancer patients per 100,000 inhabitants [4], total number of publications and number of publications per percent of gross domestic product spent on research and development [5]. Subsequently, the ranking of the five categories was summed to lead to a final ranking. A total of 8,742 publications were selected (Tables I and II). The top three countries accounted for 36.4% of publications and the United States of America (USA) produced 26.9% of the total amount. The total number of publications was the highest for the USA (2,349), Japan (854), and the United Kingdom (717, Fig. 1). The mean impact factor of registered publications was the highest for Australia, Taiwan, and the USA, with a mean impact factor of 3.24, 3.14, and 3.08, respectively. The top three countries with the highest publication rate per 10 inhabitants were the Netherlands, Ireland, and Greece. Considering the countries’ cancer incidence rates, the USA, India, and Japan showed the highest number of publications for each new cancer patient on 100,000 inhabitants per year. The USA, Italy, and the United Kingdom showed the highest number of publications per percentage of gross domestic product that countries spent on research and development (Fig. 2). Summing the ranks of these five categories resulted in the final ranking. The top three most prolific countries in the field of surgical oncology were: the USA (1), the Netherlands (2), and Taiwan (3). Furthermore, we analyzed the correlation between the total amount of publications and the number of inhabitants, the annual cancer incidence and the percentage of gross domestic product spent on research and development, per country (Table III). The financial investment reflected in percentage of gross domestic product, was not significantly correlated with the total amount of publications. The number of inhabitants per country and the annual cancer incidence, however, were significantly correlated with the total number of publications per country (R1⁄4 0.571 and 0.658, respectively). In absolute numbers the USA is the most productive country in the majority of studies, which was also confirmed in the present study. The USA its large population size, English language, and hosting of high‐ ranked journals, will likely contribute to this prolific success. The high ranking of the Netherlands was derived from its relative high number of publications for this relative small country, while Taiwan published in relatively high impact factor journals. According to our results of the correlation analyses, scientific contribution by country does not seem to improve by investing more money. However, the total amount of inhabitants per country and exposure and interest concomitant with higher cancer incidence, seem to have a significant influence on the scientific productivity of a country.

The predictive power of serum S-100B for non-sentinel node positivity in melanoma patients.

BACKGROUND Completion lymph node dissection (CLND) in sentinel node (SN) positive melanoma patients leads to substantial morbidity and costs, while only approximately 20% have a metastasis in non-sentinel nodes (NSNs). The aim of this study was to investigate if the biomarkers S-100B and Lactate Dehydrogenase (LDH) are associated with NSN positivity, to identify patients in whom CLND could safely be omitted. METHODS All SN positive patients who underwent CLND at the University Medical Centre Groningen between January 2004 and January 2015 were analysed. Patient and tumor characteristics, and serum S-100B and LDH values measured the day before CLND were statistically tested for their association with NSN positivity. RESULTS NSN positivity was found in 20.6% of the 107 patients undergoing CLND. Univariate analysis revealed male gender (p = 0.02), melanoma of the lower extremity (p = 0.05), Breslow thickness (p = 0.004), ulceration (p = 0.04), proportion of involved SNs (p = 0.045) and S-100B value (p = 0.01) to be associated with NSN positivity. LDH level was not significantly associated with positive NSNs (p = 0.39). In multivariable analysis, S-100B showed to have the strongest association with NSN positivity, within its reference interval of 0.20 μg/l (p = 0.02, odds ratio 5.71, 95% confidence interval 1.37-23.87). CONCLUSION In this study, the preoperatively measured S-100B value is the strongest predictor for NSN positivity in patients planned for CLND. Fluctuations of the S-100B level within the reference interval might give important clues about residual tumor load. Although further validation will be needed, this new closer look of S-100B could be of value in patient selection for CLND in the future.

Early mobilization after ilio-inguinal lymph node dissection for melanoma does not increase the wound complication rate

AIM Ilio-inguinal lymph node dissection for stage III melanoma is accompanied by a substantial amount of wound complications. Our treatment protocols changed in time in terms of postoperative bed rest prescriptions, being in chronological order Group A: 10 days with a Bohler Braun splint, Group B: 10 days without splint, and Group C: 5 days without splint. The aim of this study was to evaluate the effect of bed rest prescriptions on wound complications. METHODS For this study, we included all patients who underwent ilio-inguinal dissection for stage III melanoma in the period 1989-2011. Both univariate and multivariable analysis were performed to identify factors that were associated with occurrence of wound complications defined as wound infection, wound necrosis, and seroma. RESULTS Of the 204 patients analyzed, 99 suffered one or more wound complications: 51 wound infection, 29 wound necrosis, and 39 seroma. A wound complication occurred in 26 out of 64, 51 out of 89, and 22 out of 51 patients for Group A, B, and C, respectively. Univariate analysis showed age >55 (p = 0.001) and presence of comorbidity (p = 0.002) to be associated with higher incidence of wound complications. The 5 day bed rest protocol used in group C did not significantly increase the incidence of wound complications (ref = Group A: OR = 1.18; 95%CI = 0.52-2.68, p = 0.698). CONCLUSION Early mobilization did not significantly increase the overall wound complication rate after ilio-inguinal lymph node dissection for melanoma. Age >55 and comorbidity were risk factors in univariate analysis.

Laparoscopy Instructional Videos: The Effect of Preoperative Compared With Intraoperative Use on Learning Curves☆

OBJECTIVE Previous studies have shown that the use of intraoperative instructional videos has a positive effect on learning laparoscopic procedures. This study investigated the effect of the timing of the instructional videos on learning curves in laparoscopic skills training. DESIGN After completing a basic skills course on a virtual reality simulator, medical students and residents with less than 1 hour experience using laparoscopic instruments were randomized into 2 groups. Using an instructional video either preoperatively or intraoperatively, both groups then performed 4 repetitions of a standardized task on the TrEndo augmented reality. With the TrEndo, 9 motion analysis parameters (MAPs) were recorded for each session (4 MAPs for each hand and time). These were the primary outcome measurements for performance. The time spent watching the instructional video was also recorded. Improvement in performance was studied within and between groups. SETTING Medical Center Leeuwarden, a secondary care hospital located in Leeuwarden, The Netherlands. PARTICIPANTS Right-hand dominant medical student and residents with more than 1 hour experience operating any kind of laparoscopic instruments were participated. A total of 23 persons entered the study, of which 21 completed the study course. RESULTS In both groups, at least 5 of 9 MAPs showed significant improvements between repetition 1 and 4. When both groups were compared after completion of repetition 4, no significant differences in improvement were detected. The intraoperative group showed significant improvement in 3 MAPs of the left-nondominant-hand, compared with one MAP for the preoperative group. CONCLUSION No significant differences in learning curves could be detected between the subjects who used intraoperative instructional videos and those who used preoperative instructional videos. Intraoperative video instruction may result in improved dexterity of the nondominant hand.

Adipocytes in venipunctures cause falsely elevated S-100B serum values

*Corresponding author: Kevin P. Wevers, MD, PhD, Department of Surgical Oncology, University Medical Center Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands, Phone: +31 (0)50 361 23 17, Fax: +31 (0)50 361 17 45, E-mail: k.p.wevers@umcg.nl; and Department of Surgical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands Samantha Damude, Maarten G. Niebling, Harald J. Hoekstra and Schelto Kruijff: Department of Surgical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands Anneke C. Muller Kobold: Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands Letter to the Editor

Melanoom: chirurgische behandeling

De incidentie van het melanoom in Nederland is in de afgelopen twintig jaar verdubbeld tot meer dan 30 per 100.000 Nederlanders in 2011. In 2013 zal bij bijna 6000 Nederlanders de diagnose melanoom worden gesteld. De voorkeurslocatie is bij mannen op de bovenrug en bij vrouwen op de onderbenen. De belangrijkste vermijdbare risicofactor voor het ontwikkelen van een melanoom is overmatige blootstelling aan ultraviolette straling in zonlicht of zonnebanken, in het bijzonder op de kinderleeftijd. De prognose wordt bepaald door de zogeheten breslowdikte (de totale dikte van het melanoom in millimeters), aantasting van de epidermis (ulceratie) en de celdelingsactiviteit (mitose-index). De TNM-classificatie (tabel 19.1), waarvan op dit moment de zevende editie in gebruik is, is gebaseerd op deze drie factoren.

Chirurgische behandeling melanomen

SamenvattingWevers KP, Been LB, Hoekstra HJ. Chirurgische behandeling van melanomen. Huisarts Wet 2013;56(6):290-4.De incidentie van het melanoom blijft stijgen in Nederland. In diagnostiek en behandeling speelt chirurgie een belangrijke rol. De eerste diagnostische excisie, die meestal in de eerste lijn wordt uitgevoerd, is van groot belang voor het verdere beleid. Bij vastgestelde maligniteit volgt in de tweede lijn altijd een therapeutische re-excisie. De resectiemarge die de chirurg daarbij aanhoudt, hangt af van de zogeheten breslowdikte.Bij een breslowdikte > 1 mm vindt re-excisie plaats in combinatie met een schildwachtklierprocedure. Bij een ‘positieve’ schildwachtklier volgt in principe een aanvullende lymfeklierdissectie. Het moet echter nog komen vast te staan of deze procedure ook daadwerkelijk de overleving verbetert. Als er al hematogene metastasen zijn, is chirurgisch ingrijpen (metastasectomie) in sommige gevallen nog mogelijk, maar de vijfjaarsoverleving van deze procedure is slechts 20-40%.In de follow-up kijkt men vooral naar complicaties van de behandeling (wondinfectie, seroom, wondrandnecrose) en naar mogelijke locoregionale recidieven (de meeste worden ontdekt bij zelfcontrole door de patiënt). Vooral liesklierdissectie en aanvullende radiotherapie kunnen leiden tot complicaties die een snelle behandeling vereisen.AbstractWevers KP, Been LB, Hoekstra HJ. Chirurgische behandeling van melanomen. Huisarts Wet 2013;56(6):290-4.The incidence of cutaneous melanoma is rising in the Netherlands. Surgery is the cornerstone in the treatment (and staging) of melanoma. The diagnostic excision is often performed by the general practitioner, in which adequate effectuation is very important. A therapeutic re-excision is performed to increase local control. The resection margins are based on the Breslow thickness of the primary melanoma. In melanomas with a Breslow thickness of > 1 mm, a sentinel lymph node biopsy can be performed, providing the patient and physician with valuable prognostic information. In case of a positive sentinel lymph node or clinically apparent lymph node metastases, a lymph node dissection is performed. In sentinel-node positive patients, the pending MSLT-II trial should establish whether lymph node dissection improves survival compared to nodal observation using ultrasound. In case of hematogenous dissemination, highly selected patients with resectable metastases can undergo complete metastasectomy, which can lead to a 5-year survival of 20-40%. Follow-up of melanoma patients is aimed at postoperative complications (infection, seroma, necrosis), and detection of recurrent disease. For the general practitioner it is important to know that postoperative wound complications after lymph node dissections (with or without radiation therapy) are frequent and need prompt treatment.