Phase 1 Study of Hypofractionated Proton Beam Radiation Therapy in Adjuvant Pancreatic Cancer (PROTON-PANC)

PURPOSE

Despite improvement in systemic therapy, patients with pancreatic ductal adenocarcinoma (PDAC) frequently experience local recurrence. We sought to determine the safety of hypofractionated proton beam radiation therapy (PBT) during adjuvant chemotherapy.

METHODS AND MATERIALS

Nine patients were enrolled in a single-institution phase 1 trial (NCT03885284) between 2019 and 2022. Patients had PDAC of the pancreatic head and underwent R0 or R1 resection and adjuvant modified FOLFIRINOX (mFFX) chemotherapy. The primary endpoint was to determine the dosing schedule of adjuvant PBT (5 Gy × 5 fractions) using limited treatment volumes given between cycles 6 and 7 of mFFX. Patients received PBT on days 15 to 19 in a 28-day cycle before starting cycle 7 (dose level 1, DL1) or on days 8 to 12 in a 21-day cycle before starting cycle 7 (DL2).

RESULTS

The median patient age was 66 years (range, 52-78), and the follow-up time from mFFX initiation was 12.5 months (range, 6.2-37.4 months). No patients received preoperative therapy. Four had R1 resections and 5 had node-positive disease. Three patients were enrolled on DL1 and 6 patients on DL2. One dose-limiting toxicity (DLT) occurred at DL2 (prolonged grade 3 neutropenia resulting in discontinuation of mFFX after cycle 7). No other DLTs were observed. Four patients completed 12 cycles of mFFX (range, 7-12; median, 11). No patients have had local recurrence. Five of 9 patients had recurrence: 3 in the liver, 1 in the peritoneum, and 1 in the bone. Six patients are still alive, 4 of whom are recurrence-free. The median time to recurrence was 12 months (95% CI, 4 to not reached [NR]), and median overall survival was NR (95% CI, 6 to NR; 2-year survival rate, 57%).

CONCLUSIONS

PBT integrated within adjuvant mFFX was well tolerated, and no local recurrence was observed. These findings warrant further exploration in a phase 2 trial.

The Elephant in the Room: Racial Microaggressions and Implicit Bias in Surgical Training

OBJECTIVE

The aim of this study was to examine the association between race, experience of microaggressions, and implicit bias in surgical training.

BACKGROUND

There is persistent underrepresentation of specific racial and ethnic groups in the field of surgery. Prior research has demonstrated significant sex differences among those who experience microaggressions during training. However, little research has been conducted on the association between race and experiences of microaggressions and implicit bias among surgical trainees.

METHODS

A 46-item survey was distributed to general surgery residents and residents of surgical subspecialties through the Association of Program Directors in Surgery listserv and social media platforms. The questions included general information/demographic data and information about experiencing, witnessing, and responding to microaggressions during surgical training. The primary outcome was the prevalence of microaggressions during surgical training by self-disclosed race. Secondary outcomes were predictors of and adverse effects of microaggressions.

RESULTS

A total of 1624 resident responses were obtained. General surgery residents comprised 825 (50.8%) responses. The female-to-male ratio was nearly equal (815:809). The majority of respondents identified as non-Hispanic White (63.4%), of which 5.3% of residents identified as non-Hispanic Black, and 9.5% identified as Hispanic. Notably, 91.9% of non-Hispanic Black residents (n=79) experienced microaggressions. After adjustment for other demographics, non-Hispanic Black residents were more likely than non-Hispanic White residents to experience microaggressions [odds ratio (OR): 8.81, P <0.001]. Similar findings were observed among Asian/Pacific Islanders (OR: 5.77, P <0.001) and Hispanic residents (OR: 3.35, P <0.001).

CONCLUSIONS

Race plays an important role in experiencing microaggressions and implicit bias. As the future of our specialty relies on the well-being of the pipeline, it is crucial that training programs and institutions are proactive in developing formal methods to address the bias experienced by residents.

Phase I study of proton therapy in adjuvant pancreatic cancer (PROTON-PANC)

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Background: Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, with a 5-year survival rate of 10%. The current standard of care for patients with resectable disease is surgical resection followed by 6 months of adjuvant mFOLFIRINOX (mFFX) chemotherapy. As survival outcomes and distant recurrence rates improve with the use of mFFX, locoregional recurrence remains a significant cause of morbidity and mortality. We sought to integrate short-course proton radiation therapy (PRT) to the operative bed between cycles of adjuvant chemotherapy in patients with resected PDAC of the pancreatic head. Methods: Between 2019 and 2022, patients with resected PDAC with an R0 or R1 resection on adjuvant mFFX were enrolled in a phase I trial using a 3+3 dose-escalation schema (NCT03885284). Patients received mFFX as used in the PRODIGE 24 study and also received short-course PRT delivered over 1 week in 5 fractions (5 GyE each) between cycles 6 and 7 of mFFX. In dose level 1 (DL1), patients received PRT on days 15-19 in a 28-day cycle before starting cycle 7, and in dose level 2 (DL2) patients received PRT on days 8-12 in a 21-day cycle before starting cycle 7. Results: Nine patients were enrolled on the trial, median age 66 (range 52-78). Five had R0 resections, 4 had R1 resections, and 5 had node-positive disease. No patients received preoperative therapy, and none underwent vein reconstruction. Three patients were enrolled on DL1 and 6 patients on DL2. One dose limiting toxicity (DLT) occurred at DL2 (prolonged grade 3 neutropenia resulting in discontinuation of mFFX after cycle 7). No other DLTs were observed. Four patients completed the planned 12 cycles of mFFX (range 7-12, median 11). None of the patients have had local recurrence. Five of 9 patients had recurrence: 3 in the liver, 1 in the peritoneum, and 1 in the bone. Six patients are still alive, 4 of whom are recurrence free. With a median follow up from date of chemotherapy start of 12.5 months, median time to disease recurrence was 12 months (95% confidence interval [CI] 4-not reached [NR]), and median overall survival has not been reached (95% CI 6-NR, 2-year survival rate 57%). Conclusions: PRT integrated within adjuvant mFFX was well-tolerated and no local recurrence was observed for patients with resected PDAC. These findings warrant being confirmed in a phase II trial. Clinical trial information: NCT03885284 .

General surgery involvement with ventriculoperitoneal shunt insertions reduces revision rates

BACKGROUND

Ventriculoperitoneal shunts (VPS) are placed for a variety of etiologies. It is common for general surgery to assist with insertion of the distal portion in the peritoneum.

OBJECTIVE

To determine if there is a difference in revision rates in patients undergoing VPS placement with general surgery as well as those undergoing laparoscopic insertion.

METHODS

A retrospective review of all consecutive patients undergoing VPS placements was performed in a three-year period (2017-2019). Those that underwent placement with general surgery were compared to those without general surgery. Additionally, patients undergoing distal placement via mini-laparotomy versus laparoscopy were compared. Multivariable logistic regression was used to examine risk factors for distal VPS failure.

RESULTS

331 patients were included. 202 (61.0 %) underwent VPS placement with general surgery. 121 (36.6 %) patients underwent insertion via laparoscopic technique. General surgery involvement reduced operative times, decreased length of stay, and lowered overall revision rates with distal revision rates being most significant (1.5 % vs 8.5 %; p = 0.0034). Patients undergoing VPS placement via laparoscopic technique had decreased operative time, length of stay, in-hospital complications and revision rates, with significant decrease in shunt infection (1.7 % vs 7.1 %; p = 0.0366). A history of prior shunt or abdominal surgery (OR 3.826; p = 0.0282) and lack of general surgery involvement (OR 20.98; p = 0.0314) are independent risk factors for distal shunt revision in our cohort.

CONCLUSION

The use of general surgeons in VPS insertion can be of benefit by decreasing operative time, length of stay, total revisions, and distal revision rates. Further prospective studies are warranted to determine true benefit.

Meta-Analysis of Surgeon Burnout Syndrome and Specialty Differences

OBJECTIVE

Surgeon burnout compromises the quality of life of physicians and the delivery of care to patients. Burnout rates and interpretation of the Maslach Burnout Inventory (MBI) complicates the interpretation of surgeon burnout. The purpose of this study is to apply a standardized interpretation of severe surgeon burnout termed, "burnout syndrome" to analyze inherent variation within surgical specialties.

DESIGN

A systematic literature search was performed using MEDLINE, PsycINFO, and EMBASE to identify studies reporting MBI data by surgical specialty. Data extraction was performed to isolate surgeon specific data.

SETTING

A meta-analysis was performed.

RESULTS

A total of 16 cross-sectional studies were included in this meta-analysis, totaling 3581 subjects. A random effects model approximated burnout syndrome at 3.0% (95% CI: 2.0%-5.0%; I² = 78.1%). Subscale analysis of emotional exhaustion, depersonalization, and personal accomplishment indicated subscale burnout in 30.0% (CI: 25.0%-36.0%; I² = 93.2%), 34.0% (CI: 25.0%-43.0%; I² = 96.9%), and 25.0% (CI: 18.0%-32.0%; I² = 96.5%) of surgeons, respectively. Significant differences (p < 0.001) in MBI subscale scoring existed among surgical specialties.

CONCLUSIONS

Approximately 3% of surgeons suffer from extreme forms of burnout termed "burnout syndrome," although surgeon burnout may occur in up to 34% of surgeons, characterized by high burnout in 1 of 3 subscales. Surgical specialties have significantly different rates of burnout subscales. Future burnout studies should target the specialty-specific level to understand inherent differences in an effort to better understand methods of improving surgeon burnout.

Subdiaphragmatic Vagotomy With Pyloroplasty Ameliorates the Obesity Caused by Genetic Deletion of the Melanocortin 4 Receptor in the Mouse

Background/Objectives: We tested the hypothesis that abolishing vagal nerve activity will reverse the obesity phenotype of melanocortin 4 receptor knockout mice (Mc4r^−/−).

Subjects/Methods: In two separate studies, we examined the efficacy of bilateral subdiaphragmatic vagotomy (SDV) with pyloroplasty in the prevention and treatment of obesity in Mc4r^−/− mice.

Results: In the first study, SDV prevented >20% increase in body weight (BW) associated with this genotype. This was correlated with a transient reduction in overall food intake (FI) in the preventative arm of the study. Initially, SDV mice had reduced weekly FI; however, FI normalized to that of controls and baseline FI within the 8-week study period. In the second study, the severe obesity that is characteristic of the adult Mc4r^−/− genotype was significantly improved by SDV with a magnitude of 30% loss in excess BW over a 4-week period. Consistent with the first preventative study, within the treatment arm, SDV mice also demonstrated a transient reduction in FI relative to control and baseline levels that normalized over subsequent weeks. In addition to the accompanying loss in weight, mice subjected to SDV showed a decrease in respiratory exchange ratio (RER), and an increase in locomotor activity (LA). Analysis of the white fat-pad deposits of these mice showed that they were significantly less than the control groups.

Conclusions: Altogether, our data demonstrates that SDV both prevents gain in BW and causes weight loss in severely obese Mc4r^−/− mice. Moreover, it suggests that an important aspect of weight reduction for this type of monogenic obesity involves loss of signaling in vagal motor neurons.

Randomized, open-label trial of gemcitabine/nab-paclitaxel (G/NP) ± pamrevlumab (P) as neoadjuvant chemotherapy in locally advanced, unresectable pancreatic cancer (LAPC)

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Background: Pancreatic ductal adenocarcinoma (PDAC) is characterized by dense stroma and connective tissue growth factor (CTGF) overexpression. Although prolonged overall survival (OS) can be achieved through resection, only approximately 15% to 20% of patients are treated with surgery. Previously, pamrevlumab (P), a fully human monoclonal antibody blocking CTGF, was combined with gemcitabine/erlotinib (G/E) in a study of advanced PDAC. P plasma levels of > 150 μg/mL and low baseline CTGF levels resulted in prolonged OS. We hypothesize that neoadjuvant (NA) treatment of LAPC with P + G/nab-paclitaxel (NP) may alter LAPC’s stroma, increase R0 resectability, and improve OS similar to that of patients resectable at presentation. Methods: LAPC subjects, confirmed by NCCN criteria and staging laparoscopy, were randomized 2:1 to G/NP ± P for 6-cycle/24-week treatment. Safety and efficacy (resection rate, OS, progression-free survival, tumor response) were assessed. Resection was performed in subjects who met protocol-defined criteria with no contraindications. Results: As of 26 Sep 2016, 25 subjects were enrolled. Of 14 subjects in Arm A (G/NP + P), 7 completed, 2 discontinued. Of 11 subjects in Arm B (G/NP), 4 completed, 4 discontinued. 6 subjects (43%) in Arm A and 4 (36%) in Arm B experienced SAEs; no P-related SAEs were reported. Out of 7 eligible Arm A subjects, 3 were not resected. Successful resection was achieved in 4 Arm A subjects (3 R0, 1 R1) and 1 Arm B subject (R0) (Table). Conclusions: The combination of G/NP + P is feasible and well-tolerated with no incremental safety signals in this study. The addition of P suggests a trend toward increased resectability among LAPC subjects. Clinical trial information: NCT02210559. [Table: see text]

Randomized, open-label trial of gemcitabine/nab-paclitaxel (G/NP) ±FG-3019 as neoadjuvant chemotherapy in locally advanced, unresectable pancreatic cancer (LAPC)

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Background: Curative therapy for PDAC is currently achievable through resection only, but ≤ 15% of patients are candidates for surgery. FG-3019, a recombinant human mAb to connective tissue growth factor (CTGF), plus gemcitabine (G) significantly reduced tumor growth, increased apoptosis and improved survival vs G alone in the KPC mouse model. Higher FG-3019 exposure and lower baseline (BL) CTGF were independently and significantly associated with improved overall median and 1-year survival (OS) in a Ph2a trial with G and erlotinib in stage 3 or 4 PDAC. Neoadjuvant treatment of LAPC with FG-3019 combined with multidrug therapy may change the fibrotic character of LAPC and thus may make it amenable to surgical resection and potentially improve OS. Methods: Patients with unresectable LAPC (confirmed by laparoscopy) are randomized to G/NP ±FG-3019 for 6-cycle/24-week treatment. Safety, efficacy, PK and changes in CT, PET, & CA19.9 from BL through end of treatment (EOT) are assessed. Up to 4 endoscopic ultrasound (EUS) guided core biopsies are collected at BL. Protein microarrays of pre- and post-treatment biopsies are prepared from tumor and stromal cells isolated by laser capture microdissection. Surgical exploration is performed in subjects who achieved the protocol-defined criteria for possible resection. Results: To date, 11 subjects were enrolled with 5 randomized to +FG-3019 arm. There were no complications from laparoscopy or EUS core biopsies that were clinically significant or delayed dosing. Per investigator assessment, no FG-3019-related SAEs were reported, nor any identified toxicity suspected from combination of FG-3019 with chemotherapy. Overall, CA19.9 mean change from BL was −62.7% at Week 8 (n = 8), and target lesions were reduced by 20.6% (n = 6) at Week 16. Three out of 4 subjects had PET SUVmax reductions of ≥ 30% at EOT. Additional data from protein microarrays will be presented. Conclusions: Based on the limited data collected so far, this trial design is feasible and the G/NP +FG-3019 combination is well-tolerated and appears to be active. Summary results on surgical exploration of subjects will be provided later. Clinical trial information: NCT02210559.

Robotic, laparoscopic and open surgery for gastric cancer compared on surgical, clinical and oncological outcomes: a multi-institutional chart review. A study protocol of the International study group on Minimally Invasive surgery for GASTRIc Cancer-IMIGASTRIC

INTRODUCTION

Gastric cancer represents a great challenge for healthcare providers and requires a multidisciplinary treatment approach in which surgery plays a major role. Minimally invasive surgery has been progressively developed, first with the advent of laparoscopy and recently with the spread of robotic surgery, but a number of issues are currently being debated, including the limitations in performing an effective extended lymph node dissection, the real advantages of robotic systems, the role of laparoscopy for Advanced Gastric Cancer, the reproducibility of a total intracorporeal technique and the oncological results achievable during long-term follow-up.

METHODS AND ANALYSIS

A multi-institutional international database will be established to evaluate the role of robotic, laparoscopic and open approaches in gastric cancer, comprising of information regarding surgical, clinical and oncological features. A chart review will be conducted to enter data of participants with gastric cancer, previously treated at the participating institutions. The database is the first of its kind, through an international electronic submission system and a HIPPA protected real time data repository from high volume gastric cancer centres.

ETHICS AND DISSEMINATION

This study is conducted in compliance with ethical principles originating from the Helsinki Declaration, within the guidelines of Good Clinical Practice and relevant laws/regulations. A multicentre study with a large number of patients will permit further investigation of the safety and efficacy as well as the long-term outcomes of robotic, laparoscopic and open approaches for the management of gastric cancer.

TRIAL REGISTRATION NUMBER

NCT02325453; Pre-results.

Pancreaticoduodenectomy hospital resource utilization in octogenarians

BACKGROUND

Although pancreaticoduodenectomy (PD) is feasible in patients greater than or equal to 80 years, little is known about the potential strain on resource utilization.

METHODS

Outcomes and inpatient charges were compared across age cohorts (I: ≤70, II: 71 to 79, III: ≥80 years) in 99 patients who underwent PD (2005 to 2013) at our institution. The generalized linear modeling approach was used to estimate the impact of age.

RESULTS

Perioperative complications were equivalent among cohorts. Increasing age was associated with intensive care unit use, increased length of stay (LOS), and the likelihood of discharge to a skilled facility. After controlling for covariates, hospital charges were significantly higher in Cohort III (P = .006) and Cohort II (P = .035) when compared with Cohort I. However, hospital charges between Cohorts II and III were equivalent (P = .374). Complications (P = .005) and LOS (P < .001) were associated with higher hospital charges.

CONCLUSIONS

Increasing age was associated with increased intensive care unit, LOS, and discharge to skilled facilities. However, octogenarians had equivalent PD charges and outcome measures when compared with septuagenarians and future studies should validate these findings in larger national studies.

Bowel perforation associated with robust response to BRAF/MEK inhibitor therapy for BRAF-mutant melanoma: a case report

Combination BRAF/MEK inhibition has shown improved response rates and longer progression-free and overall survival for patients with BRAF-mutant metastatic melanoma. A 63-year-old female with widely metastatic BRAF V600E-mutant melanoma was treated with dabrafenib/trametinib. Ten weeks into therapy, she was treated conservatively for a partial bowel obstruction involving a lesion in the distal ileum. She presented two weeks later with CT evidence of a high-grade bowel obstruction with perforation. Emergent surgery was performed. Intraoperative inspection and pathologic analysis of the resected specimen revealed no evidence of melanoma. Seven months postoperatively she is disease free and fully functional. Rapid BRAF/MEK inhibitor-induced regression of small bowel lesions can result in bowel perforation, which is critical to distinguish from the consequences of disease progression.

Stereotactic body radiation therapy (SBRT) combined with chemotherapy for locally advanced pancreatic adenocarcinoma

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Background: The role of conventionally fractionated radiation therapy in the management of locally advanced pancreatic cancer (LAPC) is controversial. One concern about concurrent chemoradiation relates to the timing of systemic chemotherapy. In contrast to conventional radiation therapy, SBRT delivers high doses in a shorter duration resulting in minimal disruption in chemotherapy. Here we report our results of patients treated with SBRT and chemotherapy for LAPC. Methods: Twenty-seven patients treated with SBRT for LAPC at our institution from January 1, 2008 to December 31, 2012 were included in this retrospective analysis. Treatment was delivered in 5 fractions of 5 or 6 Gy per fraction in one week. The PTV included the pancreatic mass plus adjacent vasculature in most patients. The majority of patients received concurrent chemotherapy. Median time from diagnosis to SBRT was 1.9 months. Toxicities were scored using the CTCAE v.3. Survival was calculated using the Kaplan-Meier method. Results: The median age was 63 (range 45 – 90). ECOG performance status ranged from 0 – 2 and median Charlson Comorbidity Index was 3, range 0 – 7. All patients completed radiation as prescribed except one, who is excluded from survival analysis. Twenty-five patients received concurrent chemotherapy: 18 received gemcitabine, 6 received mFOLFOX and 1 received capecitabine. Two other patients received sequential chemotherapy. At the time of this analysis, 25 patients had died and the median OS from diagnosis was 13 months. Median PFS was 8.7 months. The first site of radiographic failure was local in 2 patients, local and distant in 1, and distant in 17. Of the other 7 patients, most died after clinical deterioration with no evidence of progression at last imaging. Acute toxicity was minimal. Severe late SBRT-related toxicities included one grade 4 biliary stricture and a grade 5 gastric hemorrhage without prior radiographic tumor progression. Conclusions: SBRT combined with gemcitabine or 5-FU based chemotherapy for LAPC is convenient, feasible and generally well tolerated. The outcomes of SBRT combined with chemotherapy compare favorably to the results of treatment with chemotherapy and conventional RT.

Evaluation and management of intestinal obstruction

Acute intestinal obstruction occurs when there is an interruption in the forward flow of intestinal contents. This interruption can occur at any point along the length of the gastrointestinal tract, and clinical symptoms often vary based on the level of obstruction. Intestinal obstruction is most commonly caused by intra-abdominal adhesions, malignancy, or intestinal herniation. The clinical presentation generally includes nausea and emesis, colicky abdominal pain, and a failure to pass flatus or bowel movements. The classic physical examination findings of abdominal distension, tympany to percussion, and high-pitched bowel sounds suggest the diagnosis. Radiologic imaging can confirm the diagnosis, and can also serve as useful adjunctive investigations when the diagnosis is less certain. Although radiography is often the initial study, non-contrast computed tomography is recommended if the index of suspicion is high or if suspicion persists despite negative radiography. Management of uncomplicated obstructions includes fluid resuscitation with correction of metabolic derangements, intestinal decompression, and bowel rest. Evidence of vascular compromise or perforation, or failure to resolve with adequate bowel decompression is an indication for surgical intervention.

Primary retroperitoneal mucinous cystadenoma

Primary mucinous neoplasms of the retroperitoneum, including mucinous cystadenocarcinomas, mucinous borderline tumors, and mucinous cystadenomas are uncommon tumors found exclusively in women. Since the retroperitoneum does not contain mucinous epithelium, the origin, and histogenesis of these tumors remain unclear. It is speculated that these tumors can arise from teratomas, supernumerary ovaries, or mucinous metaplasia of the retroperitoneal mesothelium. We describe a case of a primary mucinous cystadenoma of the retroperitoneum in a 44 year-old female that presented as a palpable abdominal mass. There was no evidence of recurrence 16 months after complete laparoscopic excision of the tumor. The morphology and immunohistochemical analysis in this case support the hypothesis that mucinous metaplasia of the retroperitoneal mesothelium overlying a preceding inclusion cyst can give rise to retroperitoneal mucinous tumors.

Dorsal motor nucleus of the vagus: a site for evoking simultaneous changes in crural diaphragm activity, lower esophageal sphincter pressure, and fundus tone

The sphincter mechanism at the esophagogastric junction includes smooth muscle of the lower esophagus and skeletal muscle of the crural diaphragm (CD). Smooth muscle is known to be under the control of the dorsal motor nucleus of the vagus (DMV), while central nervous system (CNS) control of the CD is unknown. The main purposes of our study were to determine the CNS site that controls the CD and whether simultaneous changes in lower esophageal sphincter (LES) pressure and CD activity occur when this site is activated. Experiments were performed on anesthetized male ferrets whose LES pressure, CD activity, and fundus tone were monitored. To activate DMV neurons, L-glutamate was microinjected unilaterally into the DMV at three areas: intermediate, rostral, and caudal. Stimulation of the intermediate DMV decreased CD activity (-4.8 +/- 0.1 bursts/min and -0.3 +/- 0.01 mV) and LES pressure (-13.2 +/- 2.0 mmHg; n = 9). Stimulation of this brain site also produced an increase in fundus tone. Stimulation of the rostral DMV elicited increases in the activity of all three target organs (n = 5). Stimulation of the caudal DMV had no effect on the CD but did decrease both LES pressure and fundus tone (n = 5). All changes in LES pressure, fundus tone, and some DMV-induced changes in CD activity (i.e., bursts/min) were prevented by ipsilateral vagotomy. Our data indicate that simultaneous changes in activity of esophagogastric sphincters and fundus tone occur from rostral and intermediate areas of the DMV and that these changes are largely mediated by efferent vagus nerves.

Single-step EUS-guided pancreatic pseudocyst drainage using a large channel linear array echoendoscope and cystotome: results in 11 patients

CONTEXT

EUS-guided transmural drainage of pancreatic pseudocyst has been reported using a linear array echoendoscope; however, placement of large 10 French stent was not feasible because of the limited diameter of the working channel. Recently linear array echoendoscopes with large working channel (3.7 to 3.8 mm) and newer accessories for pancreatic cyst puncture have become available; however, clinical data on their efficacy and safety in pancreatic pseudocyst drainage is not available.

OBJECTIVE

To evaluate efficacy and safety of a one-step real time EUS-guided pancreatic pseudocyst drainage approach using a 3.8 mm channel linear array echoendoscope and cystotome.

DESIGN

Prospective case series.

SETTING

Tertiary care hospital endoscopy unit.

PATIENTS AND INTERVENTIONS

A total of 12 EUS-guided pancreatic pseudocyst drainage procedures were performed in 11 patients with symptomatic pancreatic pseudocyst using a 3.8 mm channel linear array echoendoscope and cystotome.

MAIN OUTCOME MEASUREMENTS

Complete resolution of pancreatic pseudocyst on imaging.

RESULTS

Successful puncture of pancreatic pseudocyst and placement of 1 or 2 stents (10 Fr) was successful in all patients who were considered eligible for EUS-guided pancreatic pseudocyst drainage. Overall 9 patients out of a total of 11 (82%) were managed successfully with EUS-guided pseudocyst drainage. Two recurrences were noted over a mean follow-up period of 4 months (range 3-6 months). One patient underwent successful repeat drainage and the other patient was managed with surgical cystogastrostomy because of infected cyst contents. No major complication occurred.

LIMITATIONS

Uncontrolled, small sample size.

CONCLUSIONS

A single-step approach using a large channel (3.8 mm) linear array echoendoscope and cystotome appears feasible. This approach appears safe and effective in managing selected patients with symptomatic pancreatic pseudocysts.

Single-step EUS-guided pancreatic pseudocyst drainage using a large channel linear array echoendoscope and cystotome: results in 11 patients

CONTEXT

EUS-guided transmural drainage of pancreatic pseudocyst has been reported using a linear array echoendoscope; however, placement of large 10 French stent was not feasible because of the limited diameter of the working channel. Recently linear array echoendoscopes with large working channel (3.7 to 3.8 mm) and newer accessories for pancreatic cyst puncture have become available; however, clinical data on their efficacy and safety in pancreatic pseudocyst drainage is not available.

OBJECTIVE

To evaluate efficacy and safety of a one-step real time EUS-guided pancreatic pseudocyst drainage approach using a 3.8 mm channel linear array echoendoscope and cystotome.

DESIGN

Prospective case series.

SETTING

Tertiary care hospital endoscopy unit.

PATIENTS AND INTERVENTIONS

A total of 12 EUS-guided pancreatic pseudocyst drainage procedures were performed in 11 patients with symptomatic pancreatic pseudocyst using a 3.8 mm channel linear array echoendoscope and cystotome.

MAIN OUTCOME MEASUREMENTS

Complete resolution of pancreatic pseudocyst on imaging.

RESULTS

Successful puncture of pancreatic pseudocyst and placement of 1 or 2 stents (10 Fr) was successful in all patients who were considered eligible for EUS-guided pancreatic pseudocyst drainage. Overall 9 patients out of a total of 11 (82%) were managed successfully with EUS-guided pseudocyst drainage. Two recurrences were noted over a mean follow-up period of 4 months (range 3-6 months). One patient underwent successful repeat drainage and the other patient was managed with surgical cystogastrostomy because of infected cyst contents. No major complication occurred.

LIMITATIONS

Uncontrolled, small sample size.

CONCLUSIONS

A single-step approach using a large channel (3.8 mm) linear array echoendoscope and cystotome appears feasible. This approach appears safe and effective in managing selected patients with symptomatic pancreatic pseudocysts.

Physiological upper limits of ventricular cavity size in highly trained adolescent athletes

OBJECTIVES

To define physiological upper limits of left ventricular (LV) cavity size in trained adolescent athletes.

DESIGN

Cross sectional echocardiographic study.

SETTING

British national sports training grounds and Olympic Medical Institute.

SUBJECTS

900 elite adolescent athletes (77% boys) aged 15.7 (1.2) years participating in ball, racket, and endurance sports and 250 healthy controls matched for age, sex, and size.

MAIN OUTCOME MEASURES

LV end diastolic cavity size.

RESULTS

Compared with controls, athletes had a larger LV cavity (50.8 (3.7) v 47.9 (3.5) mm), a difference of 6%. The LV cavity was > 54 mm in 18% athletes, whereas none of the controls had an LV cavity > 54 mm. The LV cavity exceeded predicted sizes in 117 (13%) athletes. Among the athletes with LV dilatation, 78% were boys, LV size ranged from 52-60 mm, and left atrial diameter and LV wall thickness were enlarged. Systolic and diastolic function were normal. None of the athletes in the study had an LV cavity size > 60 mm. LV cavity size correlated with age, sex, heart rate, and body surface area.

CONCLUSION

Highly trained junior athletes usually have only modest increases in LV cavity size. A proportion of trained adolescent athletes have LV cavity size exceeding predicted values but, in absolute terms, LV cavity rarely exceeds 60 mm as in patients with dilated cardiomyopathy. In highly trained adolescent athletes with an LV cavity size > 60 mm and any impairment of systolic or diastolic function, the diagnosis of dilated cardiomyopathy should be considered.

Computer-enhanced laparoscopic training system (CELTS): bridging the gap

BACKGROUND

There is a large and growing gap between the need for better surgical training methodologies and the systems currently available for such training. In an effort to bridge this gap and overcome the disadvantages of the training simulators now in use, we developed the Computer-Enhanced Laparoscopic Training System (CELTS).

METHODS

CELTS is a computer-based system capable of tracking the motion of laparoscopic instruments and providing feedback about performance in real time. CELTS consists of a mechanical interface, a customizable set of tasks, and an Internet-based software interface. The special cognitive and psychomotor skills a laparoscopic surgeon should master were explicitly defined and transformed into quantitative metrics based on kinematics analysis theory. A single global standardized and task-independent scoring system utilizing a z-score statistic was developed. Validation exercises were performed.

RESULTS

The scoring system clearly revealed a gap between experts and trainees, irrespective of the task performed; none of the trainees obtained a score above the threshold that distinguishes the two groups. Moreover, CELTS provided educational feedback by identifying the key factors that contributed to the overall score. Among the defined metrics, depth perception, smoothness of motion, instrument orientation, and the outcome of the task are major indicators of performance and key parameters that distinguish experts from trainees. Time and path length alone, which are the most commonly used metrics in currently available systems, are not considered good indicators of performance.

CONCLUSION

CELTS is a novel and standardized skills trainer that combines the advantages of computer simulation with the features of the traditional and popular training boxes. CELTS can easily be used with a wide array of tasks and ensures comparability across different training conditions. This report further shows that a set of appropriate and clinically relevant performance metrics can be defined and a standardized scoring system can be designed.

Predictors of outcome in 100 consecutive laparoscopic antireflux procedures

BACKGROUND

Published success rates for surgical intervention in gastroesophageal reflux disease exceed 90%. The goal of this study was to determine if any preoperative factors could accurately predict postoperative symptom relief.

METHODS

One hundred consecutive patients undergoing laparoscopic antireflux surgery completed a detailed preoperative questionnaire, and underwent endoscopy, manometry, and 24-hour esophageal pH monitoring. Two surgeons performed all procedures in a standardized fashion. At least 2 months following operative intervention, a single interviewer, blinded to all preoperative information and procedure performed, recorded Visick and Gastroesophageal Reflux Disease-Health-Related Quality of Life scores for all patients. All follow-up was performed within 3 years of antireflux procedure.

RESULTS

The surgical success rate, as defined by Visick scores of 1-2, was 91%. Three variables were predictive of postoperative success: age <50, presence of typical symptoms at presentation, and complete resolution of symptoms with acid suppression therapy.

CONCLUSION

The study shows that surgical strategies can reproducibly control gastroesophageal reflux disease symptoms in more than 90% of patients. The optimal surgical candidate is a patient under the age of 50 whose typical symptoms completely resolve with acid suppression therapy.

Intraperitoneal macrophages and tumor immunity: A review

The macrophage (Mphi) is considered the first line of defense in immune response to foreign invaders. Increasing evidence suggests that Mphi(s) also play an important role against neoplastic cells. Mphi(s) exposed to supraphysiologic concentrations of CO(2) are suppressed. As surgeons apply newer minimally invasive techniques to oncologic therapies, it is important to evaluate the impact of these techniques on host-tumor interactions. We review the current understanding of Mphi biology with specific attention on cytotoxicity in addition to tumor immunity. Although systemic immune function is better preserved after laparoscopy than laparotomy, peritoneal Mphi(s) show reduced function after CO(2) pneumoperitoneum than exposure to air. Mphi(s) have shown cytotoxicity to syngeneic cancer cells and may play an important role in tumor surveillance. The impairment in Mphi function after CO(2) exposure may have an effect on outcome after oncologic surgery. In our understanding, Mphi(s) help destroy neoplastic cells. As CO(2) impairs Mphi activity, laparoscopy may significantly alter the host-tumor interaction.

A stepwise approach to laparoscopic Nissen fundoplication: avoiding technical pitfalls

Laparoscopic Nissen fundoplication is now widely used in the surgical management of gastroesophageal reflux disease. However, it is a complex operation that requires advanced laparoscopic skills. The learning curve is steep, and complications are directly related to the surgeon's experience level. Both experimental and clinical data demonstrate a decline in complications with increasing experience. We divided this complex procedure into logical and orderly components, to facilitate the learning process. We believe that this approach will not only reduce complications by highlighting potential problems at each stage but also make it easier to teach others.

A note on possible link between behaviour and the occurrence of lameness in dairy cows

Lameness in cattle is a major welfare problem and has important economic implications. It is known that lameness has a multifactorial causation; however, it is still not clear why some individuals are more susceptible than others to present foot lesions under the same environment. Social and individual behaviour is thought to play an important role. The aim of this study was to assess the possible relationships between social behaviour, individual time budgets, and the incidence of lameness in 40 dairy cows. The incidence of lameness in the group of cows observed was 42%. There were no differences in the mean time standing between low-, middle- and high-ranking cows. Low-ranking cows spent more time standing still in passageways and standing half in the cubicles than middle- and high-ranking cows. No differences were found in the mean time standing between cows that got lame and cows that did not get lame. However, cows that got clinically lame spent longer standing half in the cubicles and had a significantly lower index of displacements than those cows that did not get lame. This study may offer a starting point to better understand the relationships between behaviour and the occurrence of lameness in dairy cows.

Microalbuminuria and coronary heart disease in NIDDM: an incidence study

In most survival studies in NIDDM, microalbuminuria (urinary albumin excretion rate 20-200 microg/min) predicts early mortality; in cross-sectional studies, it is associated with coronary heart disease (CHD) morbidity. It is unclear, however, whether microalbuminuria is a risk factor for the development of CHD or the result of it, and little is known of the factors that predispose to the development of microalbuminuria in NIDDM. We examined these issues in a 7-year prospective study of a hospital-based cohort comprising 146 white NIDDM patients without clinical albuminuria. Microalbuminuria was a significant risk factor for both all-cause mortality (relative risk 3.94, 95% CI 2.04-7.62) and CHD mortality (relative risk 7.40, 95% CI 2.94-18.7) when adjusted for age only. Its independent predictive power did not persist, however, in age-adjusted multivariable survival analysis that allowed for the other significant risk factors: male sex, preexisting CHD, high levels of glycated hemoglobin, and high serum cholesterol. Among men free of CHD at baseline, the independent risk factors for CHD morbidity and mortality were microalbuminuria, current smoking, high diastolic blood pressure, and high serum cholesterol (all P < 0.05). For the 100 NIDDM patients with normoalbuminuria at baseline, the incidence of microalbuminuria was 29% over the 7-year period. In that group, fasting plasma glucose, current smoking, preexisting CHD, and high initial urinary albumin excretion rate were risk factors for the development of microalbuminuria (all P < 0.05). When men and women were analyzed separately, preexisting CHD was a significant risk factor in men only. These results demonstrate that microalbuminuria predicts incident clinical CHD in men with NIDDM. Preexisting CHD is also a risk factor for incident microalbuminuria in men, however, suggesting that microalbuminuria and CHD are not causally related but rather reflect common determinants.

In search of better route guidance instructions

Safety concerns have prompted designers of in-vehicle route guidance and information systems (IVRGIS) to make more use of an 'audible interface' to convey guidance instructions. Previous research has shown that, contrary to expectations, detailed guidance instructions can have a detrimental effect upon wayfinding performance, particularly for elderly individuals. In response to these findings a second series of experiments was carried out to try to improve the effectiveness of route guidance. Using the same procedure, 40 male and 40 female drivers aged 18-35 years watched video footage of journeys through an unfamiliar area, while hearing guidance that linked direction instructions to landmarks visible at the decision point. Results showed that those who heard these amended instructions performed significantly better than other groups at a wide range of tasks designed to measure the spatial knowledge that they had acquired. This group performed better than groups who heard nothing, and groups who heard full guidance. The results support the view that, whereas full guidance instructions can have a negative impact upon wayfinding performance, less complex instructions that link landmarks to directions have the capacity to enhance wayfinding performance. This is because instructions of this form strengthen the associations made between directions to be taken and the spatial location of these turns, resulting in the formation of a strong representation of the route. The results also showed that those who had been driving for 1 year or less were significantly less accurate at these tasks than those with more driving experience. This result has important implications for the widespread implementation and use of IVRGIS: suggesting that, for newly qualified drivers, who have not yet developed the ability to attend to and process information while controlling the vehicle, attending to route guidance instructions might have a detrimental effect upon driver safety.

Measurement of arterial oxygen-haemoglobin saturation in newborn lambs by pulse oximetry

Percentage arterial oxygen saturation (SpO2) was measured in 69 neonatal lambs at one, five and 10 minutes after birth using a pulse oximeter applied to the tail. The lambs were given a subjective vitality score from 1 to 4, with 1 being normal and 4 being stillborn. Of the 42 lambs born after a normal parturition, 19 were measured after one minute, 29 after five minutes and 24 after 10 minutes; the mean (sd) SpO2 values of these groups were 67 (15) per cent, 84 (9) per cent and 83 (9) per cent, respectively. Of the 27 lambs born after dystocia, 16 were measured after one minute, 18 after five minutes and 12 after 10 minutes; the mean (sd) SpO2 values of these groups were 61 (15) per cent, 69 (16) per cent and 69 (19) per cent, respectively. The values measured in the lambs born after dystocia were significantly lower than those in the lambs born normally at five and 10 minutes (P < 0.005 and P < 0.05, respectively). Of the lambs born with a vitality score of 1, 24 were measured after one minute, 33 after five minutes and 26 after 10 minutes; they had mean SpO2 values of 72 (11), 82 (10) and 81 (12) per cent, respectively. Of the lambs born with vitality scores of 2 or 3, 11 were measured after one minute, 14 after five minutes and 10 after 10 minutes; they had mean SpO2 values of 48 (6), 68 (17) and 72 (20) per cent, respectively. The SpO2 values of the lambs with vitality scores of 2 or 3 were significantly lower than those of the lambs with a vitality score of 1 at one and five minutes after birth (P < 0.0001 and P < 0.05, respectively).

Oesophageal injury associated with the administration of an anthelmintic bolus to calves

Six of 18 calves from a suckler herd which were dosed with a sustained-release anthelmintic bolus, using appropriate equipment, developed clinical signs related to oesophageal perforation. Two died as a direct result of the injuries sustained, one required surgical removal of the paraoesophageal bolus and the remaining three were managed medically. The calves were in the approximate weight range advised by the manufacturers as suitable for dosing, but some were younger than the minimum recommended age. These animals were of a fractious nature having been relatively little handed.

A double-blind crossover trial of atenolol, enalapril and the fixed combination of atenolol and nifedipine in mild and moderate hypertension

Sixty-three patients with mild to moderate hypertension completed a double-blind, randomised crossover trial of atenolol 100 mg daily, enalapril 20 mg daily and the fixed combination atenolol 50 mg and nifedipine retard 20 mg (Tenif) once daily. In the three areas of efficacy that the study compared-24-hour post dose blood pressure, control of blood pressure over the dosing period with particular reference to the waking day and attenuation of systolic blood pressure on exercise-atenolol and the fixed combination demonstrated greater efficacy than enalapril.

A primary demyelinating disorder of young cattle

The clinical signs and neuropathological changes are described in six Limousin X calves that, at about one month after birth, showed signs of blindness, nystagmus, rotation of the eyes, opisthotonos, hyperprotraction of the forelegs and, in one case, apparent seizures. Pathologically there was necrosis of the optic chiasma and focal areas of myelin sheath vacuolation or demyelination in certain areas of the brain, especially in the cerebellar peduncles. In one animal, kept alive for 7 months, there was remyelination by Schwann cells of some demyelinated axons in the focal cerebellar lesions, while other axons remained demyelinated. There was no evidence of oligodendrocyte remyelination. The cause of the condition was not determined but a genetic association is likely.

Cardiomyopathy in adult Holstein Friesian cattle in Britain

The clinical signs, pathology and breeding data of two cases of cardiomyopathy of an unusual kind in adult Holstein Friesian cattle in Britain are reported and compared with those in similar entities in Switzerland, Japan and Canada. The principal and primary lesions affect the heart and these produce secondary changes, particularly in the liver, and result in fatal congestive heart failure. The cardiac lesions consist of extensive myocyte vacuolation, endomysial and perimysial fibrosis and focal cardiac myocyte degeneration, atrophy and hypertrophy resulting in an extended range of myocyte size. Lesions affected all four heart chambers but were most severe in the ventricles. Vascular lesions, particularly moderate medial hypertrophy and intimal thickening of arterioles and arteries, occurred in heart, lung, kidney and lymph nodes. The liver showed severe fibrosis, chronic congestion and hepatocyte loss. There was a chronic multifocal nephritis. The cause is unknown, but the affected animals were full brother and sister and have a common ancestor in the male and female line five generations earlier.

Coronary heart disease and urinary albumin excretion rate in type 2 (non-insulin-dependent) diabetic patients

Associations between overnight urinary albumin excretion rate and prevalent coronary heart disease and its major risk factors were examined in a cross-sectional study of 141 Type 2 (non-insulin-dependent) diabetic patients. Mean albumin excretion rate was higher in men (geometric mean 13.5 micrograms/min; 95% confidence interval 10.3-17.6) than women (7.5 micrograms/min; 5.7-9.8, p less than 0.01). In diabetic men and women mean albumin excretion rate was higher in those with electrocardiographic and/or symptomatic evidence of coronary heart disease than in those without (men, 23.1 micrograms/min; 95% confidence interval 13.7-39.0 versus 10.6 micrograms/min; 7.9-14.2, p less than 0.01, women, 13.7 micrograms/min; 8.0-23.5 versus 5.4 micrograms/min; 4.2-6.8, p less than 0.01). Multiple logistic regression analysis was used to allow for confounding between variables. In the diabetic group as a whole, raised albumin excretion rate (p less than 0.001), gender (p less than 0.05) and systolic blood pressure (p = 0.06) entered the "best" model for coronary heart disease prediction. In women, albumin excretion rate alone (p less than 0.01) and in men albumin excretion rate (p less than 0.01) and age (p = 0.05) entered the "best" models. We conclude that albumin excretion rate is significantly associated with coronary heart disease morbidity after taking into account the confounding effects of raised blood pressure and other cardiovascular risk factors.

Lipid peroxidation and malondialdehyde in the synovial fluid and plasma of patients with rheumatoid arthritis

The concentration of lipid peroxides in the plasma and synovial fluid of 65 arthritic patients was determined using a new ion-pairing reverse phase HPLC technique. Patients with rheumatoid arthritis receiving only non-steroidal anti-inflammatory drugs, had a significantly higher mean concentration of lipid peroxides in synovial fluid samples (162 +/- 22.0 micrograms/l) than osteoarthritic patients (40.0 +/- 8.0 micrograms/l, p less than 0.0001). Mean concentrations in both groups correlated strongly with the level of beta-glucuronidase activity as a measure of lysosomal enzyme release (r = 0.71, p less than 0.0001). Contrary to previous reports by investigators using less specific methods, we were unable to demonstrate any increase in plasma levels of lipid peroxides in the rheumatoid patient. Treatment of rheumatoid arthritis with D-penicillamine was associated with a significant reduction of lipid peroxide levels (83.2 +/- 11.5 micrograms/ml, p less than 0.002), suggesting that this drug may function as an oxygen radical scavenger in the joint cavity. These results give further support to the concept of oxygen-free radicals playing an important role in the pathogenesis of chronic inflammatory disorders.

Quantitation of malondialdehyde (MDA) in plasma, by ion-pairing reverse phase high performance liquid chromatography

An ion-pairing high performance liquid chromatography method is described for the separation and quantitation of malondialdehyde in plasma. The MDA is determined as the thiobarbiturate chromogen formed by reaction of the plasma with 2-thiobarbituric acid under acid and heating conditions. However, under these conditions other interfering chromogens can also be formed. Using DEAE-cellulose chromatography followed by ion-pairing HPLC, we have been able to separate and quantitate the levels of MDA-TBA chromogen formed in plasma from other interfering chromogens. Measurements of MDA levels in the plasma of six normal individuals by HPLC gives a mean value of 4.57 +/- 0.33 nmole/ml, whereas the spectrophotometric determined value is 8.83 +/- 1.15 nmole/ml. These data suggest that some reevaluation of the numerous papers published on MDA levels in plasma using spectrophotometric methods may be necessary.

Persistent vaginal haemorrhage in five mares caused by varicose veins of the vaginal wall

Persistent bleeding from the vulva was the only presenting clinical sign in five non-pregnant pluriparous mares varying in age from eight to 20 years. These were two hunter types, one shire, one thoroughbred and one Arab pony. The haemorrhage originated from ulcerated varicose veins present on the dorsal wall of the vagina adjacent to the vestibulovaginal junction. All five mares were successfully treated, by submucosal resection (two), ligation of vessels (two) or diathermy (one). In four mares there was evidence of vulval incompetence caused by depression of the perineum. The importance of this and the role of impaired venous return during and after pregnancy are discussed.