Risk factors and outcomes of conversion in minimally invasive distal pancreatectomy: a systematic review.

PURPOSE: The reported conversion rates for minimally invasive distal pancreatectomy (MIDP) range widely from 2 to 38%. The identification of risk factors for conversion may help surgeons during preoperative planning and patient counseling. Moreover, the impact of conversion on outcomes of MIDP is unknown. METHODS: A systematic review was conducted as part of the 2019 Miami International Evidence-Based Guidelines on Minimally Invasive Pancreas Resection (IG-MIPR). The PubMed, Cochrane, and Embase databases were searched for studies concerning conversion to open surgery in MIDP. RESULTS: Of the 828 studies screened, eight met the eligibility criteria, resulting in a combined dataset including 2592 patients after MIDP. The overall conversion rate was 17.1% (range 13.0-32.7%) with heterogeneity between studies associated with the definition of conversion adopted. Only one study divided conversion into elective and emergency conversion. The main indications for conversion were vascular involvement (23.7%), concern for oncological radicality (21.9%), and bleeding (18.9%). The reported risk factors for conversion included a malignancy as an indication for surgery, the proximity of the tumor to vascular structures in preoperative imaging, higher BMI or visceral fat, and multi-organ resection or extended resection. Contrasting results were seen in terms of blood loss and length of stay in comparing converted MIDP and completed MIDP patients. CONCLUSION: The identified risk factors for conversion from this study can be used for patient selection and counseling. Surgeon experience should be considered when contemplating MIDP for a complex patient. Future studies should divide conversion into elective and emergency conversion.

The role of older age and obesity in minimally invasive and open pancreatic surgery: A systematic review and meta-analysis.

BACKGROUND/OBJECTIVES: The aim of this study was to assess the impact of older age (≥70 years) and obesity (BMI ≥30) on surgical outcomes of minimally invasive pancreatic resections (MIPR). Subsequently, open pancreatic resections or MIPR were compared for elderly and/or obese patients. METHODS: A systematic review was conducted as part of the 2019 Miami International Evidence-Based Guidelines on MIPR (IG-MIPR). Study quality assessment was according to The Scottish Intercollegiate Guidelines Network (SIGN). A meta-analysis was performed to assess the impact of MIPR or open pancreatic resections in elderly patients. RESULTS: After screening 682 studies, 13 observational studies with 4629 patients were included. Elderly patients undergoing laparoscopic distal pancreatectomy (LDP) had less blood loss (117 mL, p < 0.001) and a shorter hospital stay (3.5 days p < 0.001) than elderly patients undergoing open distal pancreatectomy (ODP). Postoperative pancreatic fistula (POPF) B/C, major complication and reoperation rate were not significantly different in elderly patients undergoing either laparoscopic or open pancreatoduodenectomy (OPD). One study compared robot PD with OPD in obese patients, indicating that patients with robotic surgery had less blood loss (mean 250 ml vs 500 ml, p = 0.001), shorter operative time (mean 381 min vs 428 min, p = 0.003), and lower rate of POPF B/C (13% vs 28%, p = 0.039). CONCLUSION: The current available limited evidence does not suggest that MIPR is contraindicated in elderly or obese patients. Additionally, outcomes in MIPR are equal or more beneficial compared to the open approach when applied in these patient groups.

The value of serial arteriography in osteosarcoma: delivery of chemotherapy, determination of therapy duration, and prediction of necrosis.

PURPOSE: To investigate the value of serial arteriography to assess tumor response, predict necrosis, and individualize the duration of a combined intravenous (IV) and intraarterial (IA) neoadjuvant chemotherapy protocol in patients with biopsy-proven high-grade osteosarcoma or malignant fibrohistiocytoma of bone. MATERIALS AND METHODS: Between July 1987 and March 2003, 109 patients completed a chemotherapy protocol of neoadjuvant IV doxorubicin and IA cisplatin. Patients were eligible regardless of age, disease stage, or disease site. A minimum of three IA cycles followed by definitive surgery was required for inclusion in the final analysis. IA dose and duration were increased for tumors larger than 10 cm. Initial arteriograms were scored as indicating mild, moderate, or marked tumor neovascularity (TNV). Subsequent arteriograms were prospectively compared with the baseline image for percent change in TNV. Treatment continued until a maximum of five cycles were administered or one of three criteria were met: (i) at least 90% decrease in TNV, (ii) plateau of effect, or (iii) no response. RESULTS: Of 408 IA procedures, 42 patients underwent three cycles, 53 underwent four, and 14 required five cycles of neoadjuvant therapy. There was a 2.5% minor complication rate. Eighty-six percent of patients exhibited at least 90% decrease in TNV and 82% exhibited good histologic response (> or =90% tumor necrosis). Serial arteriography predicted a good histologic response with an accuracy of 90% and a sensitivity of 97%. CONCLUSIONS: Serial arteriography was highly sensitive and accurately predicted good responses. This individually modified, dose-intensified neoadjuvant protocol yielded an excellent histologic response rate with minimal complications. Future endeavors should involve a multiinstitutional study of this unique approach.

The effects of antifreeze proteins on chilled and frozen meat.

The effects of cryoprotectant proteins, trivially termed 'antifreeze proteins', from the Antarctic Cod and the Winter Flounder were assessed in meat during chilling and freezing. In light-microscopy studies, bovine muscle (Sternomandibularis) samples were soaked in phosphate buffered saline with and without 0·1 mg/ml antifreeze protein. Samples were then held frozen (-20°C) or chilled (2°C) for 3 days. Samples were freeze-substituted, embedded in resin and sectioned. With antifreeze protein present, transverse sections of frozen samples had many small intracellular spaces, probably representing ice crystals. Frozen controls had much larger intracellular single spaces. Antifreeze protein had no effect on chilled samples. Similarly treated samples were examined by scanning electron microscopy using a cryostage attachment. Chilled ovine muscle samples (Peroneus longus) were soaked for various periods (0-7 days) in 0·9% saline containing various concentrations of antifreeze proteins (0-1 mg/ml). Samples were then held frozen (-20°C) or chilled (2°C) for 5 or 7 days. With frozen samples, antifreeze proteins reduced the size of ice crystals, compared to the control. This effect depended upon the concentration used and the period of soaking before the samples were frozen, but was independent of source. Antifreeze proteins had no effect on chilled samples.

Fludarabine single-agent therapy for relapsed low-grade non-Hodgkin's lymphomas: a phase II study of the German Low-Grade Non-Hodgkin's Lymphoma Study Group.

In a phase II study, 45 patients with advanced low-grade non-Hodgkin's lymphomas (NHLs) who had failed on or had relapsed after first-line chemotherapy were treated with a 5-day regimen of fludarabine, 25 mg/m2/d, by a 30-minute infusion. All patients were pretreated and had received one to 11 preceding regimens (median, three regimens). Histologic subtypes included 17 centrocytic/centroblastic NHLs, three centrocytic NHLs, 23 lymphoplasmocytoid immunocytomas, and one case each of peripheral T-cell and lymphocytic lymphoma. From 38 presently evaluable patients, 12 (31%) cases responded (five [13%] complete and seven [18%] partial remissions). Treatment-associated toxicity was mild to moderate, with myelosuppression comprising the major side effect. From the 12 complete and partial response patients, seven are currently in unmaintained remission for more than 12 months. These data indicate a high activity of fludarabine in heavily pretreated patients with low-grade NHL. Further investigations are warranted to assess the most appropriate usage for this highly promising agent at earlier stages of low-grade NHL therapy.

Virtue rewarded: reinforcement and punishment in an acute psychiatric admission ward.

This study evaluated the naturally occurring behaviour of psychiatric patients in an acute psychiatric setting. Direct behavioural observations were carried out to determine the amount of time patients spent in interaction, with whom they interacted, and the nature of the interaction. Also examined were each respondent group's type and rate of interactive behavior. For much of the time no interactive behaviour was observed to occur, but much of the behaviour exhibited by patients was socially appropriate. When social interactions did occur, both fellow patients and staff tended to reinforce appropriate behaviour. However, nurses reinforced inappropriate crazy behaviour much less than did fellow-patients or non-nursing staff. Treatment implications are discussed.

Patient interactions in four psychiatric wards.

This article describes the interactions between patients and between patients and staff in 4 psychiatric wards. Two of the wards are acute admission units and 2 are for long-stay chronic patients. The hospital is diagnostically streamed so that not only does the average length of stay vary between wards but so, for one ward, does the predominant diagnostic group. Patient interactions were analysed in terms of 5 major interactional categories: individual verbal, individual nonverbal, group verbal, group nonverbal and physical. The results show that, although there was little change in the overall level of verbal interaction as a function of chronicity, there were large shifts in patient-patient and staff-patient interaction rates. Variations between the 4 wards on the 4 other interactional categories are explained in terms of the known diagnostic characteristics of the patients.

A quantitative study of nursing staff interactions in psychiatric wards.

Data from 2 studies investigating staff-patient and staff-staff interaction rates are presented. In the first the staff-patient ratio was varied by holding patient numbers constant and systematically varying staffing levels. The results showed that although the percentage of time nurses spent interacting with patients did not change, staff-staff interaction increased as a function of increased staffing levels. In the second study the interaction rates from 4 wards were combined. These data showed that, as in the first study, staff-patient interaction remained constant, as staff numbers increased, whilst staff-staff interaction increased. However, unlike the first study, when analysed in terms of the staff-patient ratio, both categories of interaction increased as the staff-patient ratio increased.

Evaluation of a residential behavioral program for behaviorally disturbed, mentally retarded young adults.

The Adaptive Behavior Scale (ABS) was used to evaluate a three-level token economy designed to modify some aspects of the behavior of behaviorally disturbed young adults of borderline intelligence. The ABS was administered to all those referred to the program. Those admitted were retested upon discharge and 6 months later. Those not admitted, or rejected, were retested 12 months later. Results showed that initially there were few significant differences in scores between the accepted and rejected groups. Following treatment, however, large improvements occurred in those areas that were logically related to target behaviors within the token economy. These gains were maintained on follow-up. The rejected group showed no improvements over the same period.

The role of ward structure on nursing staff behaviours: an observational study of three psychiatric wards.

Variable rates of staff-patient interaction were found between three wards, which differed in the degree of programme structure, staff-patient ratios, and patient chronicity. Highest rates of staff-patient interaction occurred where a highly structured ward programme operated in a closed ward with chronically disturbed patients, and this was more likely to increase as staff-patient ratios decreased. The lowest staff-patient interaction rates occurred in acute, open and closed wards. Further, acute ward patients received negligible attention from nurses in terms of staff-patient interaction after 10 days following admission.

Head-position training through biofeedback: prosthetic or cure?

This report investigates the effectiveness of biofeedback in the treatment of poor head-positioning in patients with cerebral palsy. Four patients were given feedback of head-position trainer: two were given 20 sessions, the other two were given 10 sessions followed by 10 sessions of social reinforcement. It was found that biofeedback produced significant changes in head control during therapy but that these did not transfer well to other situations, nor did it result in long-term positive improvement. The use of social reinforcement produced excellent and long-term gains. These results are discussed in terms of stimulus properties and reinforcement conditions. General implications of this study in relation to the generalisation and maintenance of behaviour change are also discussed.

Medication and reinforcement within a token programme for disturbed mentally retarded residents.

The interaction between psychotrophic medication and a token programme as treatment modalities for mentally retarded individuals with behavioural problems was investigated in two studies. In the first, involving four residents, the dependent variables were credits earned and lost each day for performing specified behaviours within the token programme. Each subject was given a major tranquillizer in alternate months over a four month period. There was a noncontingent token phase prior to, and after completion of, the experimental phases. All subjects showed an immediate increase in the level of appropriate behaviour with the introduction of the token economy, and continuing improvements thereafter. Medication did not have a significant effect on the rate of appropriate or inappropriate behaviour. The second study assessed the relative efficacy of token reinforcement and medication in controlling behaviour symptomatic of psychosis in a resident at school and during meal-times in the ward. Five behaviours recorded were swearing, inappropriate laughter, facial grimaces, fighting, and out-of-seat. Following baseline measures, the absence of facial grimaces was reinforced in the school but not in the word. The contingencies were then reversed. A major tranquillizer was then administered, together with a replication of the first two conditions. The use of tokens to control facial grimaces resulted in the concurrent suppression of the four other symptoms. There weas no remission of any symptom as a consequence of medication alone.

The degradation of polygalacturonic acid by rumen ciliate protozoa.

The depolymerase activity of cell-free extracts of nine species of rumen ciliate protozoa and two mixed protozoal preparations, grown in vivo and in vitro, towards polygalacturonic acid was examined. The highest activity was found with Eremoplastron bovis and Ostracodinium obtusum bilobum while there was none in the spined or spineless forms of Entodinium caudatum and little in Polyplastron multivesticulatum. On the basis of the rapid drop in viscosity, inhibition by EDTA and the production of u.v.-absorbing material, the enzymes from all active species were designated as endopectate lyases (EC4.2.2.2) although some polygalacturonase may be present. Neither pectin nor polygalacturonic acid supported the survival or growth of any of the protozoal species tested.

The uptake and metabolism of bacteria, amino acids, glucose and starch by the spined and spineless forms of the rumen ciliate Entodinium caudatum.

Spined and spineless forms of Entodinium caudatum were obtained by growth in vivo in the presence and absence, respectively, of Entodinium bursa. Washed suspensions of both forms engulfed all the bacteria tested although the spined form took them up 1.3 to 1.9 times more rapidly per unit volume of protozoon than did the spineless form. Buytrivibrio fibrisolvens and Selenomonas ruminantium were rapidly digested by the spined form after engulfment. Free amino acids were taken up on average 3.1 times and glucose approximately 60 times faster per unit volume of protozoon by the spined form. Limited amounts of protein were synthesized by the spined form from glucose and starch but engulfed bacteria and, to a lesser extent, free amino acids were probably the prinicpal sources of protein for growth of both forms.