Optimized JPEG 2000 Compression for Efficient Storage of Histopathological Whole-Slide Images

Background:

Whole slide images (WSIs, digitized histopathology glass slides) are large data files whose long-term storage remains a significant cost for pathology departments. Currently used WSI formats are based on lossy image compression alogrithms, either using JPEG or its more efficient successor JPEG 2000. While the advantages of the JPEG 2000 algorithm (JP2) are commonly recognized, its compression parameters have not been fully optimized for pathology WSIs.

Methods:

We defined an optimized parametrization for JPEG 2000 image compression, designated JP2-WSI, to be used specifically with histopathological WSIs. Our parametrization is based on allowing a very high degree of compression on the background part of the WSI while using a conventional amount of compression on the tissue-containing part of the image, resulting in high overall compression ratios.

Results:

When comparing the compression power of JP2-WSI to the commonly used fixed 35:1 compression ratio JPEG 2000 and the default image formats of proprietary Aperio, Hamamatsu, and 3DHISTECH scanners, JP2-WSI produced the smallest file sizes and highest overall compression ratios for all 17 slides tested. The image quality, as judged by visual inspection and peak signal-to-noise ratio (PSNR) measurements, was equal to or better than the compared image formats. The average file size by JP2-WSI amounted to 15, 9, and 16 percent, respectively, of the file sizes of the three commercial scanner vendors' proprietary file formats (3DHISTECH MRXS, Aperio SVS, and Hamamatsu NDPI). In comparison to the commonly used 35:1 compressed JPEG 2000, JP2-WSI was three times more efficient.

Conclusions:

JP2-WSI allows very efficient and cost-effective data compression for whole slide images without loss of image information required for histopathological diagnosis.

Outcome of Surgery for Oesophageal Carcinoma in a Low Volume Centre, with and without Preoperative Chemoradiotherapy

Aims:

To critically assess the outcome of surgery for oesophageal carcinoma, with or without neoadjuvant chemoradiotherapy.

Methods:

Since April 1998 until August 2002 resectable oesophageal cancer patients referred to us have received multimodal treatment, consisting of two courses of fluorouracil, cisplatin and hydroxyurea and 20 Gy of radiotherapy followed by surgery. The outcome of this treatment was compared to the outcome of a historical group of oesophageal cancer patients, treated with surgery alone in the time period 1994 to 1998. The patients represent a consecutive series of 20 resectable oesophageal carcinomas, referred to us since 1994. Four patients (20 %) were treated for squamocellular carcinoma, 16 (80 %) patients for adenocarcinoma.

Results:

Treatment related toxicity was low and there was no death attributable to the chemoradiotherapy. Postoperative hospital mortality (< 30 days) and morbidity rates were 10 % and 50 %, respectively. A complete pathological response (T0) occurred in two of the nine patients in the multimodal group (22 %). Overall median survival was 11 months. Median survival among patients in the multimodal group was 14 months, as compared with 7 months in the group treated with surgery alone (P = 0.041).

Conclusions:

Despite low volume, outcome of surgery for oesophageal carcinoma was acceptable.

Laparoscopic Roux-en-Y gastric bypass versus laparoscopic adjustable gastric banding in the super-obese: peri-operative and early outcomes

INTRODUCTION

Controversy exists between laparoscopic Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding in super-obese patients.

METHODS

This is a retrospective review of prospectively collected data. A total of 102 consecutive super-obese (body mass index >50) patients underwent laparoscopic Roux-en-Y gastric bypass (Group 1), and 79 consecutive ones underwent laparoscopic adjustable gastric banding (Group 2). Early complications and weight loss outcomes were evaluated.

RESULTS

No significant difference was found in operative mean (± standard deviation) time (93.5 ± 33 vs 87.7 ± 39 min, p = 0.29), hospital stay (2.68 ± 2.27 vs 2.75 ± 1.84 days, p = 0.80), or overall early postoperative morbidity (17.65% and 10.12%, p = 0.20). Intra-operative complications occurred in six patients (5.9%) in Group 1 and none in Group 2 (0.0%, p = 0.04). Mean excess weight loss percent at 6 and 12 months in Group 1 was 44.75% ± 11.84% and 54.71% ± 18.18% versus 26.20% ± 12.42% and 31.55% ± 19.79% in Group 2 (p < 0.001).

CONCLUSION

There seems to be no significant differences in early complications between laparoscopic Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding operations in the short term. Weight loss and excess weight loss percent at 6 and 12 months are significantly better after laparoscopic Roux-en-Y gastric bypass.

Perioperative Morbidity, Mortality and Early Outcome of the First 360 Gastric Bypass Operations Performed in a District Hospital

Background and Aims:

We report the results for the first consecutive 360 Roux-en-Ygastric bypass (RYGB) operations performed in a district hospital in Finland.

Material and Methods:

Demographic data, perioperative characteristics, and follow-up data were entered prospectively in the hospital's database for bariatric patients.

Results:

We performed 325 primary laparoscopic Roux-en-Ygastric bypass (LRYGB) operations, one open RYGB, and 34 revisions. Mean BMI before the operations was 47.5 ± 7.8 kg/m2 (31.5–91.0 kg/m2). The percentage of patients with type 2 diabetes mellitus (T2DM) was high; 52.3% (170 patients). The mean operative time decreased from 110 minutes during the first 108 operations to 82 minutes for the second 108 operations, and to 74 minutes for the last 109 operations (P < 0.001). Postoperative hospital stay was significantly reduced (P < 0.001) for the last 109 patients compared to the first and second group of patients. Overall morbidity averaged 19.1% (62/325). Severe complications were detected in 15 patients (4.6%). There was a tendency to more serious complications in the first group of patients. There was one death (mortality 0.3%). With a follow-up rate of 97% at 3 months T2DM had resolved in 48.2%, and had resolved or improved in a minimum of 92.9% of the diabetic patients. Weight loss (WL) and excess weight loss (EWL) averaged 20% and 46% respectively.

Conclusions:

Operative time and postoperative hospital stay decrease significantly with increasing experience. The first one hundred patients may be at higher risk for complications. LRYGB operations may have an important impact on the resolution of T2DM in the operated population.

Comparision of linear versus circular stapling techniques in laparoscopic gastric bypass surgery - a pilot study

BACKGROUND

there is major variability in how the gastrojejunostomy (GJ) is created when laparoscopic gastric bypass (LRYGB) is performed. This is a prospective, non-randomised pilot comparison of two different techniques during our learning curve period performed by two different surgeons with similar surgical experience.

METHODS

from March 2006 until May 2008, 71 consecutive patients, 28 men and 43 woman, mean age 44 (range 24 to 62 years) who were operated for morbid obesity by laparoscopic by-pass surgery have been included. Mean preoperative Body Mass Index (BMI) (range) was 47 (34-63). The patients were divided into two groups on the basis of the stapler used. Group 1 comprised 30 patients who underwent surgery using a 25 mm circular stapler to create the GJ. Group 2 comprised 41 patients who underwent surgery using a 45 mm, blue cartridge linear stapler. Operative time, intra-operative complications, hospital stay, major and minor complications were detected.

RESULTS

intra-operative complications occurred in 4 patients (13.3%) in Group 1, in 5 patients (12.2%) in Group 2. Re-operations occurred 3 times (10.0%) in Group 1, and 4 times (9.8%) in Group 2 due to anastomotic complications, bleeding and/or bowel obstruction. Major complications occurred in four patients in Group 1 (13.3%) and in seven patients in Group 2 (17.1%). There was a significant difference in the overall morbidity rate (major and minor complications), which was 56.7% in Group 1 and 34.1% in Group 2 (p = 0.05). Mean operative time in Group 1 was 135 minutes, and in Group 2 122 minutes. Mean hospital stay was significantly shorter in Group 2 (3.9 days) than in Group 1 (5.7 days, p = 0.04).

CONCLUSIONS

learning to handle the technique when performing the gastrojejunostomy during laparoscopic gastric bypass surgery may be faster and easier by using the linear stapler. This may be important knowledge for centres considering starting LRYGB practice, although the surgeon factor needs to be taken in account. The results should be interpreted with caution because the confounding effect of one surge-on performing one type of operation while the other surgeon (is performing) the second type of operation could not be taken into account in this prospective non-randomized analysis.

Health-related quality of life in severely and morbidly obese patients waiting for bariatric surgery in Finland

BACKGROUND

important outcome measurements in bariatric surgery include the improvement or resolvement of medical comorbid conditions caused by obesity, and the possible changes in quality of life. The health-related quality of life (HRQoL) among Finnish obese subjects awaiting bariatric surgery has not previously been compared to age- and gender-standardized general population.

METHODS

the HRQoL in 75 obese subjects waiting for bariatric surgery was assessed by the generic 15D instrument. The resulting 15D profile and single index score were compared to those of a sample of age- and gender-standardized general population (n = 4955).

RESULTS

The patients were significantly worse off than the age- and gender-standardized general population on 11 of the 15 dimensions. The mean total 15D score among patients scheduled for bariatric surgery was 0.844 compared to 0.934 in the control group (P < 0.001).

CONCLUSION

the Finnish patients awaiting bariatric surgery suffer from a very poor HRQoL compared with age- and gender-standardized general population.

Laparoscopic floppy Nissen fundoplication for gastro-oesophageal reflux disease is feasible as a day-case procedure

BACKGROUND/AIMS

We launched a prospective study to assess the feasibility of day-case laparoscopic fundoplication for gastro-oesophageal reflux disease in March 2003. The specific aims were to assess safety, acceptability and patient satisfaction.

METHODS

The inclusion criteria were American Society of Anaesthesiologists grade I-II surgical risk, body mass index < 35, and adult company at home (less than 50 km travel) or at patient hotel (more than 50 km travel). Patients were informed about the surgical procedure, the expected postoperative course, and the possible postoperative problems and complications. Surgery was performed under general anaesthesia with proposal-infusion, fentanyl, rocuronium and sevoflurane with air + oxygen. All patients received parenteral propacetamol, NSAID, local anaesthetics and metoclopramide, as pre-emptive analgesia before awakening. A total 360 degree floppy Nissen fundoplication was performed in all patients.

RESULTS

Twenty-eight patients were included. There was one conversion to open surgery. All the other patients were discharged as planned and there were no readmissions. No intra- or postoperative complications occurred. Postoperative pain, nausea, fatigue and dysphagia were moderate. At interview the morning following the operation three patients reported they would rather have stayed over night at the hospital. However, all patients were ready for a similar procedure as day-case surgery again, if offered. At follow-up 26/28 (< 92.9%) patients were satisfied with the day-case treatment, one patient had no preference. All patients would recommend this operation as day-case surgery for a family member or friend.

CONCLUSION

Laparoscopic day-case surgery for gastro-oesophageal reflux disease appears to be safe and well tolerated by the patients.

Day-case laparoscopic cholecystectomy: treatment of choice for selected patients?

BACKGROUND

The authors report their 7-year experience with day-case laparoscopic cholecystectomy (LC) to determine its applicability, safety, and cost effectiveness.

METHODS

Of 920 consecutive patients who underwent elective LC over a 7-year period, 567 (62%) were scheduled for day-case surgery. The median age of the patients was 48 years (range, 16-74 years), and the male/female ratio was 148/419. The selection criteria required an American Society of Anesthesiologists (ASA) grade of 1 or 2, absence of morbid obesity, low risk of common bile duct stones, adult company at home, and residence within 100 km of the hospital. The LC procedure was performed using a standard four-cannula technique. Propofol-opiate-rocuron-sevoflurane anesthesia, prophylactic antiemetics, and preemptive analgesia were administered in all cases.

RESULTS

The mean length of the operation was 56 +/- 18 min. There was no hospital mortality, and 7 (1.2%) of 567 patients required conversion to open cholecystectomy. Approximately 356 (63%) of the 567 patients were discharged home on the same day as the operation, whereas 211 patients (37%) were admitted overnight after the operation because of social reasons (13.7%), surgeon preference (15.2%), nausea and/or pain (15.2%), operation late in the afternoon (14.2%), or patient preference (41.7%). There were no serious complications. A total of 22 patients visited the emergency unit, and 7 patients required readmission, giving a readmission rate of 2%. The overall postoperative morbidity rate was 6% (n = 22), with morbidities including retained stones (n = 2), bile leakage (n = 1), and pneumonia (n = 1). The mean procedural cost to the hospital was 1,836 euros for day-case LC, as compared with 2,712 euros for an inpatient operation.

CONCLUSIONS

For selected patients, day-case LC is feasible and safe, providing a substantial reduction in hospital costs.

Symptomatic outcome of laparoscopic fundoplication, using a minimal dissection technique

BACKGROUND AND AIMS

The symptomatic outcome of 135 consecutive patients operated laparoscopically for gastro-oesophageal reflux disease (GORD) by a minimal paraoesophageal dissection technique is reported.

PATIENTS AND METHODS

At a median (range) follow-up time of 25 months (6-82 months) we sent the patients a self-assessment questionnaire regarding symptomatic outcome of the operation.

RESULTS

Median (range) operation time was 65 minutes (33-185 minutes). Per- and postoperative complications occurred in four patients (3%). There were no conversions and no mortality. The answering rate was 91%. Of all patients, 87% were free of reflux symptoms, 84% without any medication, 99% reported at least improvement, 90%-95% reported persistence of favourable outcome, 90% were satisfied, 91% scored the outcome as good or excellent, and 95% of the patients were ready to recommend the operation to family or friend. However, 31% reported dysphagia and 76% troublesome gas bloating, causing problems in 24% of the patients. No association between different outcome variables and crural repair could be shown.

CONCLUSION

Laparoscopic fundoplication can be done in a simple and fast way, with minimal morbidity, short hospital stay and without compromising outcome. Nevertheless, the operation is seldom without some sequel for the patient.

Bariatric Analysis and Reporting Outcome System (BAROS) following laparoscopic adjustable gastric banding in Finland

BACKGROUND

The reporting on outcome following barlatric procedures should include changes in comorbid conditions and quality of life (QOL), in addition to weight loss. The Bariatric Analysis and Reporting Outcome System (BAROS) appears to provide the means to fulfill these requests. We have re-evaluated our previously published, initial results of laparoscopic adjustable gastric banding, using BAROS.

METHODS

Our first 60 consecutive patients were treated laparoscopically between the years 1996 and 1999, using the Swedish Adjustable Gastric Band (SAGB). After a minimum follow-up of > or = 17 months (median follow-up 28 months, range 17-61 months), a postal questionnaire concerning QOL, medical condition and excess weight loss (BAROS) was sent to the patients. In addition, the patients' opinion regarding the operation was evaluated as well as the extent that the band had caused the patients any of the more common side-effects.

RESULTS

87% of the patients returned the questionnaire properly answered. According to BAROS, the outcome was regarded as VERY GOOD in 12% of patients, GOOD in 38%, FAIR in 29% and FAILURE in 21%. Not one had an EXCELLENT outcome. 23% of the patients were disappointed with their operation. The incidence of band-related side-effects was high.

CONCLUSION

Our results are comparable with other published series including the learning curve. In our opinion, BAROS should be widely adopted.

Laparoscopic silicone adjustable gastric band: initial experience in finland

BACKGROUND

The Swedish adjustable gastric band (SAGB) was introduced in 1985 and rapidly gained popularity. Today more than 21,000 gastric banding procedures have been performed in Europe. The reported results of gastric banding operations are mainly good, although the method is not without controversies and risks. We report here our initial experience with the SAGB.

METHODS

60 patients (44 women, 16 men) were treated surgically for morbid obesity between the years 1996 and 1999, with SAGB. Median age of the patients was 44 years (range 21-64) and preoperative median Body Mass Index (BMI, kg/m(2)) was 45 (range 35-55). 3 patients were operated by an open approach, and the remaining 57 laparoscopically.

RESULTS

Operative time was 62-206 minutes (median 97 minutes). Only one operation was converted to open approach (1.8%), due to extensive adhesions. No intraoperative complications occurred. At 1 year follow-up, mean weight loss was 30 kg, mean excess weight loss was 50%, and median BMI was 35. 4 patients have been reoperated so far (6.7%) due to slippage of the band (2 patients), infection of the band (1 patient), and leaking of the filling system (1 patient). Median postoperative hospital stay was 3 days (range 2-53). Mortality was 0%. Immediate postoperative morbidity-rate was 12% (7/60), although serious morbidity occurred in only 1 patient (1.7%).

CONCLUSIONS

Laparoscopically placed adjustable gastric band is a good option for the morbidly obese patient.