Virtually transparent epidermal imagery for laparo-endoscopic single-site surgery

This paper presents a novel design, and prototype implementation, of a virtually transparent epidermal imagery (VTEI) system for laparo-endoscopic single-site (LESS) surgery. The system uses a network of multiple, micro wireless cameras and multiview mosaicing technique to obtain a panoramic view of the surgery area. This view provides visual feedback to surgeons with large viewing angles and areas of interest so that the surgeons can improve the safety of surgical procedures by being better aware of where the surgical instruments are relative to tissue and organs. The prototype VTEI system also projects the generated panoramic view on the abdomen area to create a transparent display effect that mimics equivalent, but higher risk, open-cavity surgeries.

Ultrasound-guided thoracic paravertebral puncture and placement of catheters in human cadavers: where do catheters go?

BACKGROUND

Paravertebral regional anaesthesia is used to treat pain after several surgical procedures. This study aimed to improve on our first published ultrasound-guided approach to the paravertebral space (PVS) and to investigate a possible discrepancy between the needle, catheter, and contrast dye position.

METHODS

In 10 cadavers, we conducted 26 ultrasound-guided paravertebral approaches combined with loss of resistance (LOR) and after an interim analysis performed 36 novel, pure ultrasound-guided (PUSG) paravertebral approaches. Needle-tip position was controlled by a first computed tomography (CT) scan. After placement of the catheters, the tips were assessed by a second CT and the spread of injected contrast dye was assessed by further CT scans. The part of the PVS near the intervertebral foramen was defined as the primary target to reach.

RESULTS

The first CT scans assessing 62 needle tips revealed that: 13 (50%) of LOR and 34 (94%) of PUSG approaches were at the target; and two (8%) LOR and no PUSG approaches were outside the PVS. With the second CT scans 60 catheter-tip positions were analysed: three (12%) of LOR and five (14%) of PUSG approaches were at the target, three (12%) of LOR and two (6%) of PUSG approaches were outside the PVS. No catheters were detected in the epidural space. In two cases, insertion of the catheter was not possible. In cases with major epidural contrast, the widest contrast dye spread was 7.7 (3.5) [mean (sd)] vertebral segments.

CONCLUSIONS

Our new PUSG technique has a high success rate for paravertebral needle placement. Although needles were correctly positioned, catheters were usually found distant from the needle-tip position.

The learning curve of laparoendoscopic single-site (LESS) cholecystectomy: definable, short, and safe

BACKGROUND

The applications of laparoendoscopic single-site (LESS) surgery, including cholecystectomy, are occurring quickly, although little is generally known about issues associated with the learning curve of this new technique including operative time, conversion rates, and safety.

STUDY DESIGN

We prospectively followed all patients undergoing LESS cholecystectomy, and compared operations undertaken at our institutions in cohorts of 25 patients with respect to operative times, conversion rates, and complications.

RESULTS

One-hundred fifty patients of mean age 46 years underwent LESS cholecystectomy. No significant differences in operative times were demonstrable between any of the 25-patient cohorts operated on at our institution. A significant reduction in operative times (p < 0.001) after completion of 75 LESS procedures was, however, identified with the experience of a single surgeon. No significant reduction in the number of procedures requiring an additional trocar(s) or conversion to open operations was observed after completion of 25 LESS cholecystectomies. Complication rates were low, and not significantly different between any 25-patient cohorts.

CONCLUSIONS

For surgeons proficient with multi-incision laparoscopic cholecystectomy, the learning curve for LESS cholecystectomy begins near proficiency. Operative complications and conversions were infrequent and unchanged across successive 25-patient cohorts, and were similar to those reported for multi-incision laparoscopic cholecystectomy after the learning curve.

Den-site selection is critical for Pallas’s cats (Otocolobus manul)

We evaluated the habitat selection of 101 den sites used by 21 individual Pallas’s cats ( Otocolobus manul (Pallas, 1776) = Felis manul Pallas, 1776) in summer, winter, and the maternal period in central Mongolia using generalized linear mixed models. Pallas’s cats used rock crevices and marmot burrows as dens for giving birth, raising young, thermoregulation, feeding, mating, and as important cover from predators. Den sites were selected with higher proportions of rocky and ravine habitats in the surroundings, and in winter Pallas’s cats avoided the presence of humans. Habitat and structural features suggested that dens were selected to minimize predation risk. Selection of dens in shade in summer and the use of insulated dens of Siberian marmots ( Marmota sibirica (Radde, 1862)) in winter indicated that thermal properties may also be important. We contend that dens are a critical habitat for Pallas’s cats and the availability of suitable den sites is critical for the conservation of the species. Repeated use of maternal dens suggested they may be a limiting resource. Although marmot dens are unlikely to be limiting at present, over hunting of marmots is likely to reduce burrow availability in the future.

Medical comorbidities should not deter the application of laparoscopic fundoplication

INTRODUCTION

Laparoscopic Nissen fundoplication offers significant improvement in gastroesophageal reflux disease (GERD) symptom severity and frequency. This study was undertaken to determine the impact of preoperative medical comorbidities on the outcome and satisfaction of patients undergoing fundoplication for GERD.

METHODS

Prior to fundoplication, patients underwent esophageal motility testing and 24-h pH monitoring. Before and after fundoplication, the frequency and severity of reflux symptoms were scored using a Likert scale. Medical comorbidities were classified by organ systems, and patients were assigned points corresponding to the number of medical comorbidities they had. In addition, all patients were assigned Charlson comorbidity index (CCI) scores according to the medical comorbidities they had. A medical comorbidity was defined as a preexisting medical condition, not related to GERD, for which the patient was receiving treatment. Analyses were then conducted to determine the impact of medical comorbidities as well as CCI score on overall outcome, symptom improvement, and satisfaction.

RESULTS

Six hundred and ninety-six patients underwent fundoplication: 538 patients had no medical comorbidities and 158 patients had one or more medical comorbidities. Preoperatively, there were no differences in symptom severity and frequency scores between patients with or without medical comorbidities. Postoperatively, all patients had improvement in their symptom severity and frequency scores. There were no differences in postoperative symptom scores between the patients with medical comorbidities and those without. The majority of patients were satisfied with their overall outcome; there was no relationship between the number of medical comorbidities and satisfaction scores. These findings were mirrored when patients' CCI scores were compared with satisfaction, overall outcome, and symptom improvement.

CONCLUSION

These results promote further application of laparoscopic Nissen fundoplication, even for patients with medical comorbidities.

Surgery residency training programmes have greater impact on outcomes after pancreaticoduodenectomy than hospital volume or surgeon frequency

BACKGROUND

Hospital volume of pancreaticoduodenectomy (PD) and surgeon frequency of PD have been shown to impact outcomes. The impact of surgery residency training programmes after PD is unknown. This study was undertaken to determine the impact of surgery training programmes on outcomes after PD, as well as their importance relative to hospital volume and surgeon frequency of PD.

METHODS

The State of Florida Agency for Healthcare Administration Database was queried for patients undergoing PD during 2002-2007. Measures of outcome were compared for patients undergoing PD at centres with vs. without surgery residency training programmes.

RESULTS

A total of 2345 PDs were identified, of which 1478 (63%) were undertaken at training centres and 867 (37%) were performed at non-training centres. Patients undergoing PD at training centres had shorter lengths of stay, lower hospital charges and lower in-hospital mortality. Relative to surgeon frequency of PD, training centres had a greater favourable impact on hospital length of stay, hospital charges and in-hospital mortality (P < 0.001 for each, ancova). Relative to hospital volume of PDs undertaken, training centres had a greater impact on hospital charges (P < 0.001, ancova).

CONCLUSIONS

Surgery residency training programmes have a favourable effect on outcomes following PD and their impact on outcome is greater than the impact of hospital volume or surgeon frequency of PD.

A remedial intervention linked to a formative assessment is effective in terms of improving student performance in subsequent degree examinations

BACKGROUND

Intervention may help weaker medical students improve their performance. However, the effectiveness of remedial intervention is inconclusive due to small sample sizes in previous studies. We asked: is remedial intervention linked to a formative assessment effective in terms of improving student performance in subsequent degree examinations?

METHODS

This was a retrospective, observational study of anonymous databases of student assessment outcomes. Data were analysed for students due to graduate in the years 2005-2009 (n = 909). Exam performance was compared for students who received remediation versus those who did not. The main outcome measure was summative degree examination marks.

RESULTS

After adjusting for cohort, gender, overseas versus home funding, previous degree and previous performance in the corresponding baseline third year summative exam, students receiving a remedial intervention (after poor performance on a formative objective structured clinical examination and written exams mid-fourth year) were significantly more likely to obtain an improved mark on end-of-fourth year summative written (p = 0.005) and OSCE (p = 0.001) exams compared to those students who did not receive remediation.

CONCLUSION

A remedial intervention linked to poor assessment performance predicted improved performance in later examination. There is a need for prospective studies in order to identify the effective components of remedial interventions.

Pancreaticoduodenectomy for suspected periampullary cancers: the mimes of malignancy

BACKGROUND

Pancreaticoduodenectomies are often undertaken with suspicion of malignancy. We undertook this study to determine if and how unnecessary pancreaticoduodenectomies can be avoided.

METHODS

Data from patients undergoing pancreaticoduodenectomy were prospectively collected. Operative indications, including presenting symptoms and results with imaging, with or without biopsy, were reviewed.

RESULTS

From 1996 through to 2007, 551 patients underwent pancreaticoduodenectomy at our institution. Chronic pancreatitis was the operative indication in 3% of patients; premalignant/malignant lesions were present in 86% of patients. Eleven per cent of patients underwent 'unnecessary' pancreaticoduodenectomies with presumptive diagnoses of cancer but were without premalignant/malignant disease on final report by Pathology [pancreatitis in 63%, serous cystadenomas (<4 cm) in 14%]. Of the unnecessary resections, 20% had histories and imaging sufficient to diagnose pancreatitis, 18% had inaccurate preoperative brushings/biopsies 'documenting' cancer, 11% had clear misinterpretations of their imaging studies and 7% had inadequate preoperative evaluations. However, 45% had signs/symptoms of cancer with a pancreatic head mass/biliary stricture.

CONCLUSION

Only a small minority of patients undergoing pancreaticoduodenectomy for suspicion of periampullary cancer do so unnecessarily. Preoperative review of biopsies, better considerations of pancreatitis and careful evaluation of imaging, particularly for cystic masses, will decrease unnecessary pancreaticoduodenectomies.

"There is a chain of Chinese whispers ...": empirical data support the call to formally teach handover to prequalification doctors

BACKGROUND

Changing patterns of work in the hospital setting mean different teams look after the same group of patients over the course of any given day. Shift handovers, or hand/sign-off, can give rise to miscommunication of critical information, a patient safety issue. How can we best prepare new doctors for handover?

METHODS

This was a qualitative, focus-group study, exploring the views of doctors (Foundation Year, Senior House Officers, Registrars and Consultants) and night nurse practitioners, in Aberdeen, UK.

RESULTS

Five focus groups were carried out with 21 participants. Using framework analysis, five main themes relevant to the task of effectively handing over, and how to best teach handover, emerged. These were: definition of handover; experience of handover as a junior doctor; perceptions of junior doctors' handover skills and attitudes; systems factors, and their interaction with individual factors; and the "what" and the "how" of teaching handover.

CONCLUSIONS

New doctors feel unprepared for handover and are seen as poor at handing over. Certain skills are required for effective handover, but professional attitudes are also critical. The skills identified reflect those suggested in policy documents based on expert panel views. Poor systems are a barrier to effective learning and practice. Our empirical approach adds to existing knowledge by highlighting that handover is not solely a skills-based task; there are complex interactions between individual and systems factors; and junior doctors should be prepared for handover prequalification. These data can be used to plan optimal handover teaching for medical students.

Resection of Portovenous Structures to Obtain Microscopically Negative Margins during Pancreaticoduodenectomy for Pancreatic Adenocarcinoma is Worthwhile

Locally advanced pancreatic adenocarcinoma may require resections of the portal vein and/or its major tributaries to achieve tumor extirpation, albeit with the potential for increased morbidity and mortality. However, major venous resections can impart complete tumor extirpation and thereby a survival advantage compared with resections with residual microscopic disease. This study was undertaken to determine if resection of the portal vein and/or its splenic or superior mesenteric venous (SMV) tributaries is a worthwhile endeavor. Since 1995, patients undergoing pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma have been prospectively followed. The impact of portovenous resections (portal vein, SMV, and/or splenic vein) on survival was evaluated using survival curve analysis (Mantel-Cox test). Margins were codified as R0 or R1 and data are presented as median, mean ± SD where appropriate. For 220 patients undergoing PD for pancreatic adenocarcinoma, survival was 17 months. Patients undergoing RO resections had improved survival relative to patients undergoing R1 resections (20 vs 13 months, P < 0.03). Concomitant portovenous resections were undertaken in 48 patients. There was no difference in survival after PD without portovenous resection (17 months) versus PD with portovenous resection (18 months). Resections with complete tumor extirpation (i.e., RO resections) provide superior long-term survival; all efforts to obtain RO resections should be undertaken. Portovenous resections during pancreaticoduodenectomy can be undertaken safely and are worthwhile when complete tumor extirpation is attainable.

Laparoendoscopic single site cholecystectomy: the first 100 patients

Laparoendoscopic single site (LESS) surgery promises improved cosmesis and possibly less pain. However, given the small series reported to date, true estimates of the advantages and possible disadvantages of LESS surgery remain unknown. This study was undertaken to evaluate the first 100 patients undergoing LESS cholecystectomy at our institution. Patients referred for cholecystectomy since November 2007 were considered for LESS cholecystectomy. Outcomes, including blood loss, operative time, complications, and length of stay, were recorded. Outcomes are compared with an uncontrolled concurrent group of patients undergoing multi-incision laparoscopic (i.e., conventional) cholecystectomy. One hundred patients with a median age of 44 years underwent LESS cholecystectomy; 30 patients with a median age of 46 years underwent conventional cholecystectomy over the same time period. Median operative time (70 vs 66 minutes, P = 0.67, Mann-Whitney) and hospital length of stay (1 vs 1 day, P = 0.81, Mann-Whitney) were not different for patients undergoing LESS or multi-incision cholecystectomies, respectively. Five patients undergoing LESS cholecystectomy had postoperative complications: cystic duct stump leak (one), pain control issues (three), and urinary retention (one). LESS cholecystectomy is a safe and effective alternative to conventional cholecystectomy. It can be undertaken without added operative time and provides patients with minimal, if any, scarring.

Laparoendoscopic Single Site Cholecystectomy: The First 100 Patients

Laparoendoscopic single site (LESS) surgery promises improved cosmesis and possibly less pain. However, given the small series reported to date, true estimates of the advantages and possible disadvantages of LESS surgery remain unknown. This study was undertaken to evaluate the first 100 patients undergoing LESS cholecystectomy at our institution. Patients referred for cholecystectomy since November 2007 were considered for LESS cholecystectomy. Outcomes, including blood loss, operative time, complications, and length of stay, were recorded. Outcomes are compared with an uncontrolled concurrent group of patients undergoing multi-incision laparoscopic (i.e., conventional) cholecystectomy. One hundred patients with a median age of 44 years underwent LESS cholecystectomy; 30 patients with a median age of 46 years underwent conventional cholecystectomy over the same time period. Median operative time (70 vs 66 minutes, P = 0.67, Mann-Whitney) and hospital length of stay (1 vs 1 day, P = 0.81, Mann-Whitney) were not different for patients undergoing LESS or multi-incision cholecystectomies, respectively. Five patients undergoing LESS cholecystectomy had postoperative complications: cystic duct stump leak (one), pain control issues (three), and urinary retention (one). LESS cholecystectomy is a safe and effective alternative to conventional cholecystectomy. It can be undertaken without added operative time and provides patients with minimal, if any, scarring.

The prevalence of a raised aldosterone–renin ratio (ARR) among new referrals to a hypertension clinic

The wider application of the plasma aldosterone to renin activity ratio (ARR) test has led independent groups to report a 10-fold or higher prevalence in the detection and prevalence of primary aldosteronism than previously suggested, although such figures have been contested. We determined the prevalence of a raised ARR in an unselected group of patients who were referred to the hypertension clinic at Aberdeen Royal Infirmary. Over a 4-month period, all newly referred patients had an ARR, urea and electrolytes, and 24-h ambulatory blood pressure monitoring (ABPM) performed in addition to a detailed clinical examination. One hundred and twenty-two patients (mean age 51 +/- 16 years) were examined over the study period; 57 (47%) were receiving no anti-hypertensive medication, 32(26% of total) had a normal 24-h ABPM of which 15 patients were receiving antihypertensive medication ("controlled" hypertensives) and 17(14%) were receiving no anti-hypertensive medication ("white-coat hypertensives). Twenty patients (mean age 58 +/- 11 years) were found to have a raised ARR (> 750), of which 10 patients were receiving beta-blocker therapy as part of their anti-hypertensive regimen. Patients with a raised ARR were more likely (odds ratio 3.6, 95% confidence interval 1.2-13.2, p < 0.05) to be classified as a "non-dipper" compared with those whose blood pressure fell at night. The proportion of newly referred hypertensive patients with a raised ARR is still significant and confirms that of previous studies The ratio appears to be significantly driven by a suppressed renin value and further investigation is required to clarify the status of those patients receiving anti-hypertensive medications, particularly beta-blockers.

A rare case of recurrent secretory meningioma with malignant transformation

A 72-year-old woman previously operated for a sphenoid-ridge meningioma, now presented with double vision. Histology showed a secretory meningioma with an epithelial-appearing, malignant component. Malignant transformation in a secretory meningioma is not known. This is the first report of such an occurrence.

Laparoscopic Heller myotomy for achalasia: results after 10 years

BACKGROUND

Laparoscopic Heller myotomy was first undertaken in the early 1990s, and appreciable numbers of patients with 10-year follow-up periods are now available. This study was undertaken to determine long-term outcomes after laparoscopic Heller myotomy used to treat achalasia.

METHODS

Of 337 patients who have undergone laparoscopic Heller myotomy since 1992, 47 who underwent myotomy more than 10 years ago have been followed through a prospectively maintained registry. Among many symptoms, patients scored dysphagia, chest pain, vomiting, regurgitation, choking, and heartburn before and after myotomy using a Likert scale with choices ranging from 0 (never/not bothersome) to 10 (always/very bothersome). Symptom scores before and after myotomy were compared using a Wilcoxon matched-pairs test. Data are reported as median (mean ± standard deviation).

RESULTS

The median length of the hospital stay was 2 days (mean, 3 ± 8.6 days; range, 1-60 days). Notable complications were infrequent after myotomy. There were no perioperative deaths. One patient required a redo myotomy after 5 years due to recurrence of symptoms. At this writing, 33 patients (70%) are still alive. The causes of death after discharge were unrelated to myotomy. The frequency and severity scores for dysphagia, chest pain, vomiting, regurgitation, choking, and heartburn all decreased significantly after laparoscopic Heller myotomy (p < 0.0001 for all).

CONCLUSIONS

Laparoscopic Heller myotomy can be undertaken with few complications. This procedure significantly decreases the frequency and severity of achalasia symptoms without promoting heartburn. The symptoms of achalasia are durably ameliorated by laparoscopic Heller myotomy during long-term follow-up evaluation, thereby promoting application of this procedure.

Renal haemodynamics and function following partial portal decompression

BACKGROUND

This study was undertaken to prospectively evaluate the impact of partial portal decompression on renal haemodynamics and renal function in patients with cirrhosis and portal hypertension.

METHODS

Fifteen consecutive patients (median age 49 years) with cirrhosis underwent partial portal decompression through portacaval shunting or transjugular intrahepatic portosystemic shunting (TIPS). Cirrhosis was caused by alcohol in 47%, hepatitis C in 13%, both in 33% and autoimmune factors in 7% of patients. Child class was A in 13%, B in 20% and C in 67% of patients. The median score on the Model for End-stage Liver Disease (MELD) was 14.0 (mean 15.0 +/- 7.7). Serum creatinine (SrCr) and creatinine clearance (CrCl) were determined pre-shunt, 5 days after shunting and 1 year after shunting. Colour-flow Doppler ultrasound of the renal arteries was also undertaken with calculation of the resistive index (RI) and pulsatility index (PI). Changes in the portal vein-inferior vena cava pressure gradient with shunting were determined.

RESULTS

With shunting, the portal vein-inferior vena cava gradients dropped significantly, with significant increases in PI in the early period after shunting. Creatinine clearance improved in the early post-shunt period. However, SrCr levels did not significantly improve. At 1 year after shunting, both CrCl and SrCr levels tended towards pre-shunt levels and the increase in PI did not persist.

DISCUSSION

Partial portal decompression improves mild to moderate renal dysfunction in patients with cirrhosis. Early improvements in renal function after shunting begin to disappear by 1 year after shunting.