Geert Kazemier

Pylorus preserving pancreaticoduodenectomy versus standard Whipple procedure : a prospective, randomized, multicenter analysis of 170 patients with pancreatic and periampullary tumors

Objective:A prospective randomized multicenter study was performed to assess whether the results of pylorus-preserving pancreaticoduodenectomy (PPPD) equal those of the standard Whipple (SW) operation, especially with respect to duration of surgery, blood loss, hospital stay, delayed gastric emptying (DGE), and survival. Summary Background Data:PPPD has been associated with a higher incidence of delayed gastric emptying, resulting in a prolonged period of postoperative nasogastric suctioning. Another criticism of the pylorus-preserving pancreaticoduodenectomy for patients with a malignancy is the radicalness of the resection. On the other hand, PPPD might be associated with a shorter operation time and less blood loss. Methods:A prospective randomized multicenter study was performed in a nonselected series of 170 consecutive patients. All patients with suspicion of pancreatic or periampullary tumor were included and randomized for a SW or a PPPD resection. Data concerning patients’ demographics, intraoperative and histologic findings, as well as postoperative mortality, morbidity, and follow-up up to 115 months after discharge, were analyzed. Results:There were no significant differences noted in age, sex distribution, tumor localization, and staging. There were no differences in median blood loss and duration of operation between the 2 techniques. DGE was observed equally in the 2 groups. There was only a marginal difference in postoperative weight loss in favor of the standard Whipple procedure. Overall operative mortality was 5.3%. Tumor positive resection margins were found for 12 patients of the SW group and 19 patients of the PPPD group (P < 0.23). Long-term follow-up showed no significant statistical differences in survival between the 2 groups (P < 0.90). Conclusions:The SW and PPPD operations were associated with comparable operation time, blood loss, hospital stay, mortality, morbidity, and incidence of DGE. The overall long-term and disease-free survival was comparable in both groups. Both surgical procedures are equally effective for the treatment of pancreatic and periampullary carcinoma.

Robust surgery loading

We consider the robust surgery loading problem for a hospital’s operating theatre department, which concerns assigning surgeries and sufficient planned slack to operating room days. The objective is to maximize capacity utilization and minimize the risk of overtime, and thus cancelled patients. This research was performed in collaboration with the Erasmus MC, a large academic hospital in the Netherlands, which has also provided historical data for the experiments. We propose various constructive heuristics and local search methods that use statistical information on surgery durations to exploit the portfolio effect, and thereby to minimize the required slack. We demonstrate that our approach frees a lot of operating room capacity, which may be used to perform additional surgeries. Furthermore, we show that by combining advanced optimization techniques with extensive historical statistical records on surgery durations can significantly improve the operating room department utilization.

A master surgical scheduling approach for cyclic scheduling in operating room departments

This paper addresses the problem of operating room (OR) scheduling at the tactical level of hospital planning and control. Hospitals repetitively construct operating room schedules, which is a time-consuming, tedious, and complex task. The stochasticity of the durations of surgical procedures complicates the construction of operating room schedules. In addition, unbalanced scheduling of the operating room department often causes demand fluctuation in other departments such as surgical wards and intensive care units. We propose cyclic operating room schedules, so-called master surgical schedules (MSSs) to deal with this problem. In an MSS, frequently performed elective surgical procedure types are planned in a cyclic manner. To deal with the uncertain duration of procedures we use planned slack. The problem of constructing MSSs is modeled as a mathematical program containing probabilistic constraints. Since the resulting mathematical program is computationally intractable we propose a column generation approach that maximizes the operation room utilization and levels the requirements for subsequent hospital beds such as wards and intensive care units in two subsequent phases. We tested the solution approach with data from the Erasmus Medical Center. Computational experiments show that the proposed solution approach works well for both the OR utilization and the leveling of requirements of subsequent hospital beds.

The need for a prophylactic gastrojejunostomy for unresectable periampullary cancer - A prospective randomized multicenter trial with special focus on assessment of quality of life

Objective: To evaluate the effect of a prophylactic gastrojejunostomy on the development of gastric outlet obstruction and quality of life in patients with unresectable periampullary cancer found during explorative laparotomy. Summary Background Data: Several studies, including one randomized trial, propagate to perform a prophylactic gastrojejunostomy routinely in patients with periampullary cancer found to be unresectable during laparotomy. Others suggest an increase of postoperative complications. Controversy still exists in general surgical practice if a double bypass should be performed routinely in these patients. Methods: Between December 1998 and March 2002, patients with a periampullary carcinoma who were found to be unresectable during exploration were randomized to receive a double bypass (hepaticojejunostomy and a retrocolic gastrojejunostomy) or a single bypass (hepaticojejunostomy). Randomization was stratified for center and presence of metastases. Patients with gastrointestinal obstruction and patients treated endoscopically for more than 3 months were excluded. Primary endpoints were development of clinical gastric outlet obstruction and surgical intervention for gastric outlet obstruction. Secondary endpoints were mortality, morbidity, hospital stay, survival, and quality of life, measured prospectively by the EORTC-C30 and Pan26 questionnaires. It was decided to perform an interim analysis after inclusion of 50% of the patients (n = 70). Results: Five of the 70 patients randomized were lost to follow-up. From the remaining 65 patients, 36 patients underwent a double and 29 a single bypass. There were no differences in patient demographics, preoperative symptoms, and surgical findings between the groups. Clinical symptoms of gastric outlet obstruction were found in 2 of the 36 patients (5.5%) with a double bypass, and in 12 of the 29 patients (41.4%) with a single bypass (P = 0.001). In the double bypass group, one patient (2.8%) and in the single bypass group 6 patients (20.7%) required (re-)gastrojejunostomy during follow-up (P = 0.04). The absolute risk reduction for reoperation in the double bypass group was 18%, and the numbers needed to treat was 6. Postoperative morbidity rates, including delayed gastric emptying, were 31% in the double versus 28% in the single bypass group (P = 0.12). Median postoperative length of stay was 11 days (range 4–76 days) in the double versus 9 days (range 6–20 days) in the single bypass group (P = 0.06); median survival was 7.2 months in the double versus 8.4 months in the single bypass group (P = 0.15). No differences were found in the quality of life between both groups. After surgery most quality of life scores deteriorated temporarily and were restored to their baseline score (t = −1) within 4 months. Conclusions: Prophylactic gastrojejunostomy significantly decreases the incidence of gastric outlet obstruction without increasing complication rates. There were no differences in quality of life between the two groups. Together with the previous randomized trial from the Hopkins group, this study provides sufficient evidence to state that a double bypass consisting of a hepaticojejunostomy and a prophylactic gastrojejunostomy is preferable to a single bypass consisting of only a hepaticojejunostomy in patients undergoing surgical palliation for unresectable periampullary carcinoma. Therefore, the trial was stopped earlier than planned.

Similar liver transplantation survival with selected cardiac death donors and brain death donors

The outcome of orthotopic liver transplantation (OLT) with controlled graft donation after cardiac death (DCD) is usually inferior to that with graft donation after brain death (DBD). This study compared outcomes from OLT with DBD versus controlled DCD donors with predefined restrictive acceptance criteria.

Hepatocyte‐derived microRNAs as serum biomarkers of hepatic injury and rejection after liver transplantation

Recent animal and human studies have highlighted the potential of hepatocyte‐derived microRNAs (HDmiRs) in serum as early, stable, sensitive, and specific biomarkers of liver injury. Their usefulness in human liver transplantation, however, has not been addressed. The aim of this study was to investigate serum HDmiRs as markers of hepatic injury and rejection in liver transplantation. Serum samples from healthy controls and liver transplant recipients (n = 107) and peritransplant liver allograft biopsy samples (n = 45) were analyzed via the real‐time polymerase chain reaction quantification of HDmiRs (miR‐122, miR‐148a, and miR‐194). The expression of miR‐122 and miR‐148a in liver tissue was significantly reduced with prolonged graft warm ischemia times. Conversely, the serum levels of these HDmiRs were elevated in patients with liver injury and positively correlated with aminotransferase levels. HDmiRs appear to be very sensitive because patients with normal aminotransferase values (<50 IU/L) had 6‐ to 17‐fold higher HDmiR levels in comparison with healthy controls (P < 0.005). During an episode of acute rejection, serum HDmiRs were elevated up to 20‐fold, and their levels appeared to rise earlier than aminotransferase levels. HDmiRs in serum were stable during repeated freezing and thawing. In conclusion, this study shows that liver injury is associated with the release of HDmiRs into the circulation. HDmiRs are promising candidates as early, stable, and sensitive biomarkers of rejection and hepatic injury after liver transplantation. Liver Transpl 18:290–297, 2012.

Endoscopic Retroperitoneal Adrenalectomy: Lessons Learned From 111 Consecutive Cases

ObjectiveTo evaluate the effectiveness of endoscopic retroperitoneal adrenalectomy (ERA). Summary Background DataMinimally invasive adrenalectomy has become the procedure of choice for benign adrenal pathology. Although the adrenal glands are located in the retroperitoneum, most surgeons prefer the transperitoneal laparoscopic approach to adrenal tumors. MethodsClinical characteristics and outcomes of 111 ERAs from January 1994 to December 1999 were evaluated. ResultsNinety-five patients underwent 111 ERAs (79 unilateral, 16 bilateral). Indications were Cushing syndrome (n = 22), Cushing disease (n = 8), ectopic adrenocorticotropic hormone syndrome (n = 6), Conn’s adenoma (n = 25), pheochromocytoma (n = 19), incidentaloma (n = 11), and other (n = 4). Tumor size varied from 0.1 to 8 cm. Median age was 50 years. Unilateral ERA required 114 minutes, with median blood loss of 65 mL. Bilateral ERA lasted 214 minutes, with median blood loss of 121 mL. The conversion rate to open surgery was 4.5%. The complication rate was 11%. Median postoperative hospital stay was 2 days for unilateral ERA and 5 days for bilateral ERA. The death rate was 0.9%. At a median follow-up of 14 months, the recurrence rate of disease was 0.9%. ConclusionFor benign adrenal tumors less than 6 cm, ERA is recommended.

Laparoscopic vs open appendectomy : A randomized clinical trial

AbstractBackground: A randomized clinical trial was performed to compare open appendectomy (OA) and laparoscopic appendectomy (LA). Methods: 201 patients with similar characteristics of appendicitis were randomized to either OA or LA. Operative time and technique, reintroduction of diet, postoperative pain, use of analgesia, hospital stay, and complications were documented. Results: 104 patients were allocated to the OA group and 97 to the LA group. Postoperative pain was significantly less in the LA group on the 1st (p < 0.001) and 2nd (p < 0.001) postoperative day, resulting in less use of analgesics on both days (p < 0.001). Restoration of diet was similar in both groups. Mean operative time was longer in the LA group: 61 vs 41 min (p < 0.001). Postoperative complications did not differ in either group, except for wound infections (six OA group vs zero LA group, p < 0.05). Mean hospital stay was similar in both groups. Conclusions: LA results in less postoperative pain and fewer wound infections. The laparoscopic procedure is technically more demanding to perform, resulting in longer operative time.

Improving operating room efficiency by applying bin-packing and portfolio techniques to surgical case scheduling

BACKGROUND:An operating room (OR) department has adopted an efficient business model and subsequently investigated how efficiency could be further improved. The aim of this study is to show the efficiency improvement of lowering organizational barriers and applying advanced mathematical techniques. METHODS:We applied advanced mathematical algorithms in combination with scenarios that model relaxation of various organizational barriers using prospectively collected data. The setting is the main inpatient OR department of a university hospital, which sets its surgical case schedules 2 wk in advance using a block planning method. The main outcome measures are the number of freed OR blocks and OR utilization. RESULTS:Lowering organizational barriers and applying mathematical algorithms can yield a 4.5% point increase in OR utilization (95% confidence interval 4.0%–5.0%). This is obtained by reducing the total required OR time. CONCLUSIONS:Efficient OR departments can further improve their efficiency. The paper shows that a radical cultural change that comprises the use of mathematical algorithms and lowering organizational barriers improves OR utilization.

A Randomized, Controlled Study to Assess the Conversion From Calcineurin-Inhibitors to Everolimus After Liver Transplantation—PROTECT

Posttransplant immunosuppression with calcineurin inhibitors (CNIs) is associated with impaired renal function, while mTor inhibitors such as everolimus may provide a renal‐sparing alternative. In this randomized 1‐year study in patients with liver transplantation (LTx), we sought to assess the effects of everolimus on glomerular filtration rate (GFR) after conversion from CNIs compared to continued CNI treatment. Eligible study patients received basiliximab induction, CNI with/without corticosteroids for 4 weeks post‐LTx, and were then randomized (if GFR > 50 mL/min) to continued CNIs (N = 102) or subsequent conversion to EVR (N = 101). Mean calculated GFR 11 months postrandomization (ITT population) revealed no significant difference between treatments using the Cockcroft‐Gault formula (−2.9 mL/min in favor of EVR, 95%‐CI: [−10.659; 4.814], p = 0.46), whereas use of the MDRD formula showed superiority for EVR (−7.8 mL/min, 95%‐CI: [−14.366; −1.191], p = 0.021). Rates of mortality (EVR: 4.2% vs. CNI: 4.1%), biopsy‐proven acute rejection (17.7% vs. 15.3%), and efficacy failure (20.8% vs. 20.4%) were similar. Infections, leukocytopenia, hyperlipidemia and treatment discontinuations occurred more frequently in the EVR group. No hepatic artery thrombosis and no excess of wound healing impairment were noted. Conversion from CNI‐based to EVR‐based immunosuppression proved to be a safe alternative post‐LTx that deserves further investigation in terms of nephroprotection.