Trypanosomiasis: An emerging disease in Alpine swift (Tachymarptis melba) nestlings in Switzerland?

Alpine swifts (Tachymarptis melba) are sub-Saharan migratory birds, which, in Switzerland, nest in colonies that have been continuously monitored for over 40 years. In the summer of 2022, despite favourable environmental conditions, an unexpectedly high number of sudden mortalities (30-80%) occurred in 20 to 45-day-old nestlings from several nesting sites, of which 3 were monitored in detail. Nestlings submitted for post-mortem analysis (n = 5) were in good body condition but exhibited extensive subcutaneous haematomas (n = 5), myocardial petechiae (n = 2) and stunted growth of primary feathers (n = 1). In all birds, 4-5 μm large, amastigote-like protozoans were identified in skeletal and cardiac muscle sections. These tissues tested positive in a PCR targeting the 18S-rRNA gene of Trypanosoma spp. Amplified sequences showed 99.63% identity with sequences of Trypanosoma corvi (JN006854 and AY461665) and Trypanosoma sp. (AJ620557, JN006841). 72 blood smears of 45-day-old nestlings from two colonies were assessed, of which 20 contained trypomastigote forms, some with high parasitaemia (highest average of 56.4 in 10 high power fields, 400x magnification). Trypomastigote morphometrics (n = 36; mean total length = 30.0 μm; length of free flagellum = 5.8 μm) were consistent with those of T. bouffardi. These findings suggest that an avian trypanosomiasis causing mass nestling mortality could be an emerging disease in Swiss Alpine swift populations.

Strongyle faecal egg counts in Swiss horses: A retrospective analysis after the introduction of a selective treatment strategy

The standard parasite management of horses based on regular anthelmintic treatments, now practiced for decades has resulted in a worrying expansion of resistant helminth populations, which may considerably impair control on the farm level. The aim of the present study was to obtain a retrospective (year 2010 - 2016) nationwide analysis of faecal egg count (FEC) data from the Swiss adult horse population, related to horse age and geographic region. Thirteen labs provided a total of 16,387 FEC data of horses aged four to 39 years (average: 13.6 years). The annual number of performed FEC tests increased from 38 to 4,939 within the observation period. Independent of the annual sample size the yearly patterns of the FEC were very similar. Seventy-eight percent (n = 12,840) of the samples were negative and 90 % (n = 14,720) showed a FEC below 200 strongyle eggs per gram (EPG) of faeces. The annual mean strongyle FEC ranged between 60 and 88 EPG with a total mean of 75 EPG. Horses aged 4-7 years showed a significantly (p < 0.00001) higher mean FEC compared with the other age groups, differences were not significant among the older horses. Based on ZIP codes, samples were allocated by 70.0 %, 6.0 % and 0.2 % to the German-, French- and Italian-speaking regions of Switzerland, respectively. With 222 EPG the mean FEC in the French part of Switzerland was significantly higher (p < 0.05) than in the German-speaking region (60 EPG). Eggs of Parascaris spp., anoplocephalids and Strongyloides westeri were found in 0.36 %, 0.32 % and 0.01 % of the samples, respectively. Based on 3,813 questionnaire feedbacks from owners in 2017 covering a total of 12,689 horses, sixty-eight percent (n = 8,476) were dewormed without diagnosis, two percent (n = 240) were not dewormed at all, whereas for 30 % (n = 3,721) the selective anthelmintic treatment (SAT) concept was applied. The SAT implementation rate differed significantly (p < 0.0005) between regions, with 33 %, 20 % and 25 % for the German-, French- and Italian-speaking areas, respectively. The rate of horses spending 16-24 h on pasture per day was significantly higher in the French-speaking region compared to the German-speaking part of Switzerland (p < 0.0001). In addition, pasture hygiene was practiced at a significantly lower rate in the French-speaking part compared to the German- and Italian-speaking regions (both p < 0.0001). Overall, the shift towards the SAT-concept represents a very promising development with respect to mitigating the further spread of anthelmintic resistance.

Biliary Enterocytozoon bieneusi infection in a dog under immunomodulatory therapy

An 8-year-old female spayed Labrador retriever was presented for the evaluation of severe weight loss 10 weeks after starting an immunomodulatory treatment, including prednisolone and cyclosporine, for meningoencephalitis of unknown origin. Plasma biochemistry analysis showed mild to moderate increases in liver enzyme activities and a moderate decrease in urea concentration. Abdominal ultrasound revealed mild hepatomegaly and a large gall bladder with unremarkable wall and content. Cholecystocentesis was performed and bile was examined both cytologically and by molecular methods, which revealed the presence of Enterocytozoon bieneusi. Treatment was initiated with albendazole but was discontinued due to the development of severe neutropenia. The medical management was subsequently changed to fenbendazole and the dog made a complete recovery. This report describes the first case of clinical manifestation and successful treatment of biliary E. bieneusi infection in a dog.

The golden jackal (Canis aureus): A new host for Echinococcus multilocularis and Trichinella britovi in Switzerland

INTRODUCTION

The golden jackal (Canis aureus) is a wild canid new to Switzerland. It is an officially monitored species and all deceased individuals are submitted for post-mortem examination to collect baseline health data. This includes parasitological examinations, with an emphasis on zoonotic, reportable infections, such as those caused by Trichinella spp. or Echinococcus spp. From 2016 to 2021, five golden jackals originating from four Swiss cantons were submitted for full post-mortem examination. In one case only organ samples were available, and therefore parasitological examination was not possible. Parasite stages recovered during necropsy, as well as by routine coproscopical techniques, were morphologically identified. Taeniid eggs and adult tapeworms were processed for molecular species identification. Additionally, tongue and diaphragm were analysed for Trichinella spp. by the artificial digestion technique followed by multiplex-PCR in positive cases. Of the four jackals investigated for parasites, hookworm eggs were detected in one animal, both adult worms and eggs of Echinococcus multilocularis were present in another case, and one animal was free of parasites. Eggs of E. multilocularis as well as eggs of Toxocara canis and sporocysts of Sarcocystis sp. were detected in the intestinal content, and Trichinella britovi larvae were found in the muscle samples of the last case. The health monitoring programme in place for protected carnivores in Switzerland allowed us to add the golden jackal to the list of hosts for the endemic zoonotic parasites E. multilocularis and T. britovi in this country. Hunters, farmers, and other persons who could come in contact with golden jackals should be aware of the associated health risk and handle faeces and carcasses with caution.

Causes of mortality and morbidity in free-ranging mustelids in Switzerland: necropsy data from over 50 years of general health surveillance

BACKGROUND

Although mustelids occur worldwide and include a wide range of species, little is known about the diseases affecting them. Mustelids have regularly been submitted for post mortem investigation in the framework of the program for general wildlife health surveillance in Switzerland, which has been in place for nearly 60 years. We performed a retrospective analysis of the necropsy reports on mustelids submitted to the diagnostic service of the University of Bern. The aims of this study were to present an overview of the causes of mortality and morbidity observed in these carnivores, to assess differences among species, to assess changes in disease detection over the study period, and to describe the pathology of selected diseases.

RESULTS

Five hundred and sixty-six reports from 1958 to 2015 were analyzed. Most animals were stone martens (Martes foina, 46%) and badgers (Meles meles, 44%); the remaining species were polecats (Mustela putorius, 4.7%), pine martens (Martes martes, 2%), stoats (Mustela erminea, 1.4%), weasels (Mustela nivalis, 0.8%) and otters (Lutra lutra, 0.3%). Infectious diseases (n = 262) were frequent and were mostly bacterial or viral; non-infectious conditions (n = 169) were less common and were mostly traumatic or due to metabolic disorders. The most frequent diagnoses included distemper (75% were badgers), amyloidosis (96% were martens), bacterial respiratory infections (all mustelids), biting lice (badgers only) and pulmonary and gastro-intestinal helminths (all species). Less frequent diseases included histoplasmosis (badgers only), aspergillosis, toxoplasmosis, hepatozoonosis, and sarcoptic mange. Lesions due to infection with distemper virus were primarily appreciated in the respiratory tract and central nervous system; they presented species-specific characteristics such as necrosis in the ependyma in badgers and absence of syncytia in stone martens. Amyloidosis in martens was multisystemic in most cases and included both AA and AL amyloidosis; the main macroscopic change was severe splenomegaly.

CONCLUSION

Infectious diseases were the most frequent causes of morbidity and mortality of mustelids, with marked species-specific differences. Lung and skin were the most commonly affected organs. Contagious diseases such as canine distemper, sarcoptic mange and rabies in mustelids showed a similar temporal pattern as in red foxes (Vulpes vulpes), suggesting pathogen spillovers from foxes to mustelids.

Dogs as victims of their own worms: Serodiagnosis of canine alveolar echinococcosis

Background

Besides acting as definitive hosts for Echinococcus multilocularis, dogs can become infected by the larval form of this parasite and thereby develop life-threatening alveolar echinococcosis (AE). Although AE is a zoonotic disease, most therapeutic and diagnostic approaches have been developed for human patients. In dogs, AE is typically diagnosed in the advanced stage of the disease when the parasitic mass has already caused abdominal distension. At that stage, complete resection of the parasitic mass is often impossible, leaving a guarded prognosis for the affected dogs. For humans, sensitive and specific diagnostic protocols relying on serology have been validated and are now widely used. In contrast, sensitive and specific laboratory diagnostic tools that would enable early diagnosis of canine AE are still lacking. The aim of the current study was to establish a serological protocol specifically adapted to dogs.

Methods

We tested several native and recombinant antigens (EmVF, Em2, recEm95, recEm18) in in-house ELISA, an in-house Western blot (WB), as well as a commercially available WB developed for serodiagnosing human AE (Anti-Echinococcus EUROLINE-WB®), using a panel of known status dog sera.

Results

RecEm95-antigen was revealed to be the most promising antigen for use in ELISA, demonstrating 100% (95% CI: 72–100%) sensitivity and 100% (95% CI: 93–100%) specificity in our study. The in-house WB using EmVF antigen performed as well as the recEm95-ELISA. The commercial WB also correctly identified all infected dogs, coupled with a specificity of 98% (95% CI: 91–100%).

Conclusion

The recEm95-ELISA alone or in combination with either the in-house WB or the Anti-Echinococcus EUROLINE-WB® (IgG) with a minor modification should be considered as the best current approach for the serological diagnosis of dogs infected with the larval stage of E. multilocularis. However, larger studies with a focus on potentially cross-reacting sera should be undertaken to verify these findings.

Clinical presentation, diagnosis, therapy and outcome of alveolar echinococcosis in dogs

Alveolar echinococcosis (AE), a parasitic disease primarily of the liver caused by the larval stage of Echinococcus multilocularis, is highly endemic in Switzerland. In contrast to well-established management protocols in people, little is known with regard to optimal treatment strategies in dogs. The objective of this study was to describe the clinical signs and diagnostic procedures in dogs with AE and to evaluate outcome following medical treatment alone or surgery and medical treatment. Of 23 putative AE cases between 2004 and 2014, 20 were classified as confirmed (n=18) or probable (n=2) AE, based on abdominal ultrasound, serology, cytology, histology and/or PCR. Most dogs presented with abdominal distension in an advanced stage of disease. Dogs receiving specific treatment (radical or debulking surgery together with medical treatment, or medical treatment alone) survived longer than dogs left untreated, but no difference was found between treatment types. Survival at one year was associated with absence of free abdominal fluid, absence of abdominal distension and treatment of any type. However, dogs treated with debulking surgery all faced relapse. Findings of this study suggest that in AE-affected dogs for which a therapeutic approach is regarded appropriate by owners and veterinarians, radical surgical resection and medical treatment or, if total resection is not possible, medical treatment alone should be considered. However, studies on larger numbers of dogs are necessary before definitive treatment recommendations can be made.

Follow-up of 100 dogs with acute diarrhoea in a primary care practice

This study aimed to examine the aetiology of acute diarrhoea and the relapse rate in 100 client-owned dogs presented to a first-opinion clinic. History, physical examination, faecal testing and owner questionnaire data were collected at initial presentation (T0) and at either the time of relapse or at a recheck performed within 3 months. All dogs received treatment according to their clinical signs. Of 96 dogs that completed the study, 37 (38.5%) relapsed during the study period, 21 (21.9%) relapsed within 3 months, and 16 others (16.6%) at 3 months to 1 year after initial examination. Dogs that had undergone a change in housing location within 1 month prior to presentation and dogs <1 year old were significantly more likely to have positive parasitological analyses (P=0.02 and P=0.001, respectively). Pica was a risk factor for relapse (P=0.0002).

Chronic bovine besnoitiosis: intra-organ parasite distribution, parasite loads and parasite-associated lesions in subclinical cases

Bovine besnoitiosis caused by Besnoitia besnoiti is a chronic and debilitating disease. The most characteristic clinical signs of chronic besnoitiosis are visible tissue cysts in the scleral conjunctiva and the vagina, thickened skin and a generally poor body condition. However, many seropositive animals remain subclinically infected, and the role that these animals may play in spreading the disease is not known. The aim of the present study was to assess the intra-organ parasite distribution, the parasite load and the parasite-associated lesions in seropositive but subclinically infected animals. These animals were seropositive at the time of several consecutive samplings, had visible tissue cysts in the past and, at time of slaughter, had detectable specific anti-Besnoitia spp. antibody levels, but they did not show evident clinical signs at culling. Thus, histopathological, immunohistochemical and molecular analyses of several samples from the respiratory tract, reproductive tract, other internal organs and skin from six cows were performed. The tissue cysts were located primarily in the upper respiratory tract, i.e., in the rhinarium and larynx/pharynx (four cows), followed by the distal genital tract (vulva/vagina) and the skin of the neck (three and two cows, respectively, out of the four cows with cysts in the respiratory tract). We were unable to detect any parasites in the two remaining cows. Cysts were associated with a significant non-purulent inflammatory infiltrate consisting predominantly of T lymphocytes and activated monocytes/macrophages in two cows. The parasite burden, estimated by quantitative real-time PCR, was very low. It is noteworthy that the only animal that showed a recent increase in the antibody titre had the highest parasite burden and the most conspicuous inflammatory reaction against the cysts. In conclusion, although these cows no longer displayed any visible signs of besnoitiosis, they remained infected. Therefore, cows without visible signs of disease may still be able to transmit the parasite.

An inter-laboratory comparative study of serological tools employed in the diagnosis of Besnoitia besnoiti infection in bovines

Bovine besnoitiosis is considered an emerging chronic and debilitating disease in Europe. Many infections remain subclinical, and the only sign of disease is the presence of parasitic cysts in the sclera and conjunctiva. Serological tests are useful for detecting asymptomatic cattle/sub-clinical infections for control purposes, as there are no effective drugs or vaccines. For this purpose, diagnostic tools need to be further standardized. Thus, the aim of this study was to compare the serological tests available in Europe in a multi-centred study. A coded panel of 241 well-characterized sera from infected and non-infected bovines was provided by all participants (SALUVET-Madrid, FLI-Wusterhausen, ENV-Toulouse, IPB-Berne). The tests evaluated were as follows: an in-house ELISA, three commercial ELISAs (INGEZIM BES 12.BES.K1 INGENASA, PrioCHECK Besnoitia Ab V2.0, ID Screen Besnoitia indirect IDVET), two IFATs and seven Western blot tests (tachyzoite and bradyzoite extracts under reducing and non-reducing conditions). Two different definitions of a gold standard were used: (i) the result of the majority of tests ('Majority of tests') and (ii) the majority of test results plus pre-test information based on clinical signs ('Majority of tests plus pre-test info'). Relative to the gold standard 'Majority of tests', almost 100% sensitivity (Se) and specificity (Sp) were obtained with SALUVET-Madrid and FLI-Wusterhausen tachyzoite- and bradyzoite-based Western blot tests under non-reducing conditions. On the ELISAs, PrioCHECK Besnoitia Ab V2.0 showed 100% Se and 98.8% Sp, whereas ID Screen Besnoitia indirect IDVET showed 97.2% Se and 100% Sp. The in-house ELISA and INGEZIM BES 12.BES.K1 INGENASA showed 97.3% and 97.2% Se; and 94.6% and 93.0% Sp, respectively. IFAT FLI-Wusterhausen performed better than IFAT SALUVET-Madrid, with 100% Se and 95.4% Sp. Relative to the gold standard 'Majority of test plus pre-test info', Sp significantly decreased; this result was expected because of the existence of seronegative animals with clinical signs. All ELISAs performed very well and could be used in epidemiological studies; however, Western blot tests performed better and could be employed as a posteriori tests for control purposes in the case of uncertain results from valuable samples.

A study to demonstrate freedom from Trichinella spp. in domestic pigs in Switzerland

Trichinellosis is a food-borne zoonotic disease caused by the nematode Trichinella spp. Many omnivorous and carnivorous animal species can act as host for this parasite, including domestic pigs. To protect public health, it should be ensured that pork should not contain infective Trichinella larvae. Surveillance for Trichinella spp. can be done using direct (larval detection) and indirect (antibody detection) diagnostic techniques. The aim of this study was to demonstrate the absence of infection in Swiss domestic pigs. An ELISA was used as the initial screening test, and sera reacting in ELISA were further investigated using both a Western blot for serology and an artificial digestion test with 20 g of diaphragm tissue for larval detection. A total of 7412 adult pigs, 9973 finishing pigs and 2779 free-ranging pigs were tested. Samples from 17 (0.23%) adult pigs, 16 (0.16%) finishing pigs and nine (0.32%) free-ranging pigs were ELISA-positive, but all of these sera were subsequently negative by Western blot and by the artificial digestion method. Based on these findings, an absence of Trichinella infections in adult pigs (target prevalence 0.04%) and finishing pigs (target prevalence 0.03%) can be concluded. The results also demonstrated that the prevalence of Trichinella infections does not exceed 0.11% in free-ranging pigs, the group with the highest risk of exposure.

Toxoplasma gondii in Switzerland: a serosurvey based on meat juice analysis of slaughtered pigs, wild boar, sheep and cattle

Toxoplasmosis is one of the most important zoonotic diseases worldwide and is caused by the protozoan Toxoplasma gondii. Besides vertical infection during pregnancy, humans can get infected post-natally either by peroral uptake of sporulated Toxoplasma oocysts or by ingestion of tissue cysts upon consumption of raw or undercooked meat. The aim of this study was to approximate the risk of human infection via meat consumption by estimating the seroprevalence of T. gondii in slaughtered animals in Switzerland and to compare data with prevalences assessed 10 years ago. The study included pigs, cattle, sheep and wild boar of different age groups and housing conditions whenever possible and applicable. A P-30-ELISA was used to detect T. gondii-specific antibodies and to determine seroprevalences in meat juice of slaughtered animals. A total of 270 domestic pigs (120 adults, 50 finishing, 100 free-ranging animals), 150 wild boars, 250 sheep (150 adults, 100 lambs) and 406 cattle (47 calves, 129 heifers, 100 bulls, 130 adult cows) were tested. Seropositivity increased with the age of the assessed animals. Independent of the age-group, the overall seroprevalence was lowest in wild boars (6.7%), followed by pigs (23.3%), cattle (45.6%) and sheep (61.6%), respectively. Conventional fattening pigs and free-ranging pigs surprisingly had comparable seroprevalences (14.0% and 13.0%, respectively). Unlike in other European countries, where generally a decrease in the number of seropositive animals had been observed, we found that the prevalence of seropositive animals, when compared with that of 10 years ago, had increased for most species/age groups. Conclusively, the results demonstrated a high seroprevalence of T. gondii in animals slaughtered for meat production and revealed that increasing age of the animals is a more important risk factor than housing conditions in Switzerland.

Prevalence and genotypes of Toxoplasma gondii in feline faeces (oocysts) and meat from sheep, cattle and pigs in Switzerland

The protozoan parasite Toxoplasma gondii infects almost all warm blooded animal species including humans, and is one of the most prevalent zoonotic parasites worldwide. Post-natal infection in humans is acquired through oral uptake of sporulated T. gondii oocysts or by ingestion of parasite tissue cysts upon consumption of raw or undercooked meat. This study was undertaken to determine the prevalence of oocyst-shedding by cats and to assess the level of infection with T. gondii in meat-producing animals in Switzerland via detection of genomic DNA (gDNA) in muscle samples. In total, 252 cats (44 stray cats, 171 pet cats, 37 cats with gastrointestinal disorders) were analysed coproscopically, and subsequently species-specific identification of T. gondii oocysts was achieved by Polymerase Chain Reaction (PCR). Furthermore, diaphragm samples of 270 domestic pigs (120 adults, 50 finishing, and 100 free-range animals), 150 wild boar, 250 sheep (150 adults and 100 lambs) and 406 cattle (47 calves, 129 heifers, 100 bulls, and 130 adult cows) were investigated by T. gondii-specific real-time PCR. For the first time in Switzerland, PCR-positive samples were subsequently genotyped using nine PCR-restriction fragment length polymorphism (PCR-RFLP) loci (SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) for analysis. Only one of the cats shed T. gondii oocysts, corresponding to a T. gondii prevalence of 0.4% (95% CI: 0.0-2.2%). In meat-producing animals, gDNA prevalence was lowest in wild boar (0.7%; 95% CI: 0.0-3.7%), followed by sheep (2.0%; 95% CI: 0.1-4.6%) and pigs (2.2%; 95% CI: 0.8-4.8%). The highest prevalence was found in cattle (4.7%; 95% CI: 2.8-7.2%), mainly due to the high prevalence of 29.8% in young calves. With regard to housing conditions, conventional fattening pigs and free-range pigs surprisingly exhibited the same prevalence (2.0%; 95% CI: 0.2-7.0%). Genotyping of oocysts shed by the cat showed T. gondii with clonal Type II alleles and the Apico I allele. T. gondii with clonal Type II alleles were also predominantly observed in sheep, while T. gondii with mixed or atypical allele combinations were very rare in sheep. In pigs and cattle however, genotyping of T. gondii was often incomplete. These findings suggested that cattle in Switzerland might be infected with Toxoplasma of the clonal Types I or III, atypical T. gondii or more than one clonal Type.

Increased parasite resistance and recurrent airway obstruction in horses of a high-prevalence family

BACKGROUND

Equine recurrent airway obstruction (RAO) shares many characteristics with human asthma. In humans, an inverse relationship between susceptibility to asthma and resistance to parasites is suspected.

HYPOTHESIS/OBJECTIVES

Members of a high-incidence RAO half-sibling family (F) shed fewer strongylid eggs compared with RAO-unaffected pasture mates (PM) and that RAO-affected horses shed fewer eggs than RAO-unaffected half-siblings.

ANIMALS

Seventy-three F and 73 unrelated, age matched PM.

METHODS

Cases and controls kept under the same management and deworming regime were examined. Each individual was classified as RAO affected or RAO unaffected and fecal samples were collected before and 1-3 weeks and 3 months after deworming. Samples were analyzed by combined sedimentation-flotation and modified McMaster methods and classified into 3 categories of 0 eggs per gram of feces (EpG), 1-100 EpG, and > 100 EpG, respectively.

RESULTS

PM compared with RAO-affected F had a 16.7 (95% confidence interval [CI]: 2.0-136.3) times higher risk for shedding > 100 EpG compared with 0 EpG and a 5.3 (95% CI: 1.0-27.4) times higher risk for shedding > 100 EpG compared with 0 EpG. There was no significant effect when RAO-unaffected F were compared with their PM. RAO-unaffected compared with RAO-affected offspring had a 5.8 (95% CI: 0.0-1.0) times higher risk for shedding 1-100 EpG. Age, sex, breed, and sharing pastures with other species had no significant confounding effects.

CONCLUSION AND CLINICAL IMPORTANCE

RAO is associated with resistance against strongylid parasites in a high-prevalence family.

An autochthonous case of cutaneous bovine leishmaniasis in Switzerland

The present case report describes a novel etiological agent of cutaneous leishmaniasis that appears for the first time in a cow. A similar agent had recently been described as causing autochthonous infections in horses of Germany and Switzerland. The infection in the cow was initially diagnosed upon clinical and immunohistological findings. Subsequent comparative sequence analysis of diagnostic PCR products from the internal transcribed spacer 1 (ITS1) of ssrRNA classified the respective isolate as neither Old World nor New World Leishmania species, but yielded complete identity of the analysed sequence with the above mentioned horse cases and 98% identity to Leishmania sp. siamensis, an organism recently identified in a visceral leishmaniasis patient from Thailand. The potential transmitting vectors for all these cases have not yet been identified. Future investigations will have to elucidate the veterinary-epidemiological relevance of this etiological agent, as well as biological parameters such as transmission mode and geographical origin and distribution.

Validation of a Western Blot for the detection of anti-Trichinella spp. antibodies in domestic pigs

Trichinellosis is a zoonotic disease in humans caused by Trichinella spp. According to international regulations and guidelines, serological surveillance can be used to demonstrate the absence of Trichinella spp. in a defined domestic pig population. Most enzyme-linked immunosorbent assay (ELISA) tests presently available do not yield 100% specificity, and therefore, a complementary test is needed to confirm the diagnosis of any initial ELISA seropositivity. The goal of the present study was to evaluate the sensitivity and specificity of a Western Blot assay based on somatic Trichinella spiralis muscle stage (L1) antigen using Bayesian modeling techniques. A total of 295 meat juice and serum samples from pigs negative for Trichinella larvae by artificial digestion, including 74 potentially cross-reactive sera of pigs with other nematode infections, and 93 meat juice samples from pigs infected with Trichinella larvae were included in the study. The diagnostic sensitivity and specificity of the Western Blot were ranged from 95.8% to 96.0% and from 99.5% to 99.6%, respectively. A sensitivity analysis showed that the model outcomes were hardly influenced by changes in the prior distributions, providing a high confidence in the outcomes of the models. This validation study demonstrated that the Western Blot is a suitable method to confirm samples that reacted positively in an initial ELISA.

The Frey procedure: local resection of pancreatic head combined with lateral pancreaticojejunostomy

Management of chronic pancreatitis is mainly palliative. Most patients with chronic pancreatitis require surgical evaluation and intervention when there is suspicion of pancreatic malignancy, evidence of intractable pain, or development of pancreatitis-related local complications. The ideal operation for chronic pancreatitis, therefore, should be designed to exclude the existence of malignancy, provide long-lasting pain relief, and correct the local complications. It should be as simple and safe as possible and should preserve the remaining endocrine and exocrine functions of the pancreas.

Intrathecal morphine delivered via subcutaneous pump for intractable pain in pancreatic cancer

BACKGROUND

Pain secondary to unresectable pancreatic cancer is frequently severe and extremely difficult to control with traditional methods of analgesia. This retrospective study reports the analgesic effects of intrathecal morphine sulfate by implanted infusion pumps in nine patients with unresectable adenocarcinoma of the pancreas.

METHODS

Nine patients were implanted over a 2-year period. Preoperative morphine i.v. equivalents were a mean of 81.51 mg/day, with a range of 20-140 mg/day. Patients were hospitalized for a trial dose of 1-2 mg of intrathecal Duramorph, 1 mg/ml, via lumbar puncture to assess whether adequate pain relief could be achieved and whether there would be drug-related side effects.

RESULTS

All patients who received a trial dose experienced excellent pain relief, and subsequently underwent implantation of a lumbar subarachnoid catheter and infusion pump during the same hospitalization. The mean number of days from diagnosis to pump implant was 119, with a range of 3-587 days. The mean maximum daily dose was 21.28 mg, with a range of 3-73.10 mg. No patient experienced respiratory depression or excess sedation which prevented achievement of pain control. Minor supplemental narcotic use was documented in three of the nine patients. Assessment of pain control was made by the level of activity and the analog pain scale, with 0 being no pain and 10 being the worst pain imaginable. All of the patients experienced good to excellent relief of pain. The mean duration of intrathecal morphine sulfate use until death was 137.3 days, with a range of 52-354 days.

CONCLUSIONS

This series of nine patients indicates that long-term administration of intrathecal morphine via implanted infusion pump in patients with pancreatic cancer is both efficacious and safe. All patients and their families reported an improved quality of life with an increased level of activity.

Tumors of the pancreas with osteoclast-like and pleomorphic giant cells: an immunohistochemical and ploidy study

BACKGROUND

Tumors of the pancreas with osteoclast-like giant cells are of uncertain histogenesis and aggressiveness. Their relationship, if any, to undifferentiated (anaplastic) carcinomas of the pancreas with pleomorphic giant cells is also not clear.

METHODS

Eleven tumors with osteoclast-like giant cells were studied by immunohistochemistry for epithelial and mesenchymal markers, as well as for a proliferation marker (Ki67) and p53 protein expression. Cytometric image analysis for nuclear DNA content was also performed. K-ras mutations were investigated by DNA sequence analysis.

RESULTS

Neoplastic, predominantly spindle-shaped cells and osteoclast-like giant cells were positive for mesenchymal markers CD68, LCA, and A1ACT. These spindle-shaped cells were also positive for human muscle actin. Spindle-shaped cells of seven tumors were also positive for epithelial markers carcinoembryonic antigen, epithelial membrane antigen, or keratin. Nine tumors contained a variable number of pleomorphic giant cells in addition to osteoclast-like giant cells. Pleomorphic giant cells were much less positive for mesenchymal markers than were osteoclast-like giant cells, but they were positive for some epithelial markers. A high percentage of spindle-shaped and pleomorphic giant cells were positive for Ki67. Diploid and aneuploid populations were present in varying proportions in both spindle cells and pleomorphic giant cells. The nuclei of osteoclast-like giant cells, however, were diploid and not proliferating. Spindle-shaped and pleomorphic giant cells were positive for p53 protein in 5 of 10 cases. Five of six tumors studied were positive for K-ras mutations.

CONCLUSION

The distinction between tumors with osteoclast-like giant cells and undifferentiated carcinomas with pleomorphic giant cells is often not clear-cut. Both types of tumors have mesenchymal and epithelial characteristics in varying proportions and may arise from an undifferentiated pancreatic stem cell. Long-term survival of two patients suggests that some tumors with osteoclast-like giant cells may have a better prognosis than the usual pancreatic ductal adenocarcinoma.

Current approach to the surgical management of chronic pancreatitis

The indications for surgical intervention in chronic pancreatitis are suspicion of malignancy, local complications, and intractable pain. Chronic pancreatitis is a risk factor for development of pancreatic carcinoma, and carcinomas may present, initially with a clinical picture of chronic pancreatitis. Local complications of chronic pancreatitis such as common bile duct or duodenal obstruction and enlarging or symptomatic pseudocyst also mandate surgical intervention. Thrombosis of the splenic vein with left-sided portal hypertension is common and associated with a 10% incidence of gastric variceal hemorrhage, which requires splenectomy. The role of surgery in the management of pain associated with chronic pancreatitis is to provide relief. When the pain interferes substantially with the patient's quality of life or narcotics are required for pain relief, surgical intervention is indicated. Other factors that should be incorporated in assessing the need for surgical intervention are malnutrition due to the inability to eat or malabsorption, the need for frequent hospitalization, and the inability to work. The operation selected for chronic pancreatitis should correct or deal with all structural abnormalities, provide long-term pain relief, have a low mortality and morbidity rate, minimize subsequent exocrine and endocrine insufficiency, and have results independent of abstinence from alcohol. No single operation can provide an optimal solution to the management of pain or these diverse complications of chronic pancreatitis. The operation chosen must be individualized to treat the patient's needs.

The role of antibiotic prophylaxis in severe acute pancreatitis

OBJECTIVE

To assess the impact of intravenous (IV) antibiotic prophylaxis on the incidence of pancreatic infection and the mortality rate in severe acute pancreatitis.

DESIGN

Restropective review of a cohort of 180 patients with severe acute pancreatitis.

SETTING

A tertiary referral center in Sacramento, Calif.

INTERVENTION

The use of IV antibiotic prophylaxis evolved during 3 periods from no antibiotics in 50 patients (1982-1989), to nonprotocol use in 55 patients (1990-1992), to a 4-week course of imipenem-cilastatin sodium (1993-1996) given to 75 patients having Acute Physiology and Chronic Health Evaluation (APACHE) II scores greater than 6 and pancreatic necrosis (> 15% of the gland), peripancreatic necrosis, or peripancreatic collection.

MAIN OUTCOME MEASURES

Pancreatic infection and mortality.

RESULTS

Without antibiotic prophylaxis, the incidence of pancreatic infection was 76% (38/50). Intravenous antibiotic prophylaxis reduced the infection rate of 45% (25/55) (P = .03). The imipenem-cilastatin protocol further reduced the infection rate to 27% (20/75) (P = .04). The mortality rates showed only a decreasing trend, from 16% (1982-1989) to 7% (1990-1992) to 5% (1993-1996) (P = .11). Patients with sterile severe acute pancreatitis had a mortality rate of 2% (2/97); whereas 17% (14/83) of patients with infection succumbed to the disease. Patients developing infection within the first 4 weeks from the onset of illness had mortality rates ranging from 19% to 40%, compared with 0% to 8% for those who became infected after 4 weeks. No patient with pancreatic infection developing after 4 weeks died with the imipenem-cilastatin protocol.

CONCLUSIONS

Intravenous antibiotic prophylaxis significantly reduced the infection rate in severe acute pancreatitis, with only a trend toward improved survival. A prospective, randomized, double-blind multicenter trial comparing the efficacy of different types and/or combinations of antibiotic prophylaxis in severe acute pancreatitis is indicated.

Efficacy of enzyme supplementation after surgery for chronic pancreatitis

Although surgical procedures that improve pancreatic drainage alleviate abdominal pain in the vast majority of patients with chronic pancreatitis, postoperative absorption and nutritional status are less predictable. The present study was designed to determine the efficacy of pancreatic enzyme supplementation in maintaining postoperative digestion and nutrition in patients who had received the local resection-longitudinal pancreaticojejunostomy (LR-LPJ) procedure for chronic pancreatitis. We evaluated nutritional status and intestinal absorption in 11 patients who had undergone LR-LPJ. The efficacy of postoperative pancreatic enzyme supplementation was studied by measurements of intestinal absorption and nutritional status at baseline, after 4 weeks of individualized daily dosage of pancreatin (Creon), and after an additional 4 weeks of randomization to receive another 4 weeks of pancreatin or placebo. All patients demonstrated abnormal digestion of fat, protein, and total energy at baseline 3 weeks after surgery. Pancreatin supplementation significantly improved the coefficients of absorption of dietary fat and total energy over the next 4 weeks. Between 4 and 8 weeks, pancreatin significantly improved protein absorption and nitrogen balance, whereas placebo substitution worsened the absorption of dietary fat and total energy. Nutritional status was not significantly altered over the 8-week study period, although four patients receiving pancreatin gained more than 3.6 kg body weight. The data suggest that long-term postoperative pancreatic enzyme supplementation is both efficacious and necessary in chronic pancreatitis patients after LR-LPJ.

Improved predictions from a severity characterization of trauma (ASCOT) over Trauma and Injury Severity Score (TRISS): results of an independent evaluation

OBJECTIVE

In 1986, data from 25,000 major trauma outcome study patients were used to relate Trauma and Injury Severity Score (TRISS) values to survival probability. The resulting norms have been widely used. Motivated by TRISS limitations, A Severity Characterization of Trauma (ASCOT) was introduced in 1990. The objective of this study was to evaluate and compare TRISS and ASCOT probability predictions using carefully collected and independently reviewed data not used in the development of those norms.

DESIGN

This was a prospective data collection for consecutive admissions to four level I trauma centers participating in a major trauma outcome study.

MATERIALS AND METHODS

Data from 14,296 patients admitted to the four study sites between October 1987 through 1989 were used. The indices were evaluated using measures of discrimination (disparity, sensitivity, specificity, misclassification rate, and area under the receiver-operating characteristic curve) and calibration [Hosmer-Lemeshow goodness-of-fit statistic (H-L)].

MEASUREMENTS AND MAIN RESULTS

For blunt-injured adults, ASCOT has higher sensitivity than TRISS (69.3 vs. 64.3) and meets the criterion for model calibration (H-L statistic < 15.5) needed for accurate z and W scores. The TRISS does not meet the calibration criterion (H-L = 30.7). For adults with penetrating injury, ASCOT has a substantially lower H-L value than TRISS (20.3 vs. 138.4), but neither meets the criterion. Areas under TRISS and ASCOT ROC curves are not significantly different and exceed 0.91 for blunt-injured adults and 0.95 for adults with penetrating injury. For pediatric patients, TRISS and ASCOT sensitivities (near 77%) and areas under receiver-operating characteristic curves (both exceed 0.96) are comparable, and both models satisfy the H-L criterion.

CONCLUSIONS

In this age of health care decisions influenced by outcome evaluations, ASCOT's more precise description of anatomic injury and its improved calibration with actual outcomes argue for its adoption as the standard method for outcome prediction.

Gastrointestinal and pancreatic complications associated with severe pancreatitis

OBJECTIVE

To study the outcomes of gastrointestinal fistulas and pancreatic ductal disruption in severe pancreatitis.

SETTING

University tertiary referral center.

PATIENTS

One hundred thirty-six patients from 1982 to 1994.

INTERVENTION

Diversion followed by resection and ostomy closure for gastrointestinal fistulas, pancreaticojejunostomy for pancreatic fistulas, and excision, external drainage, or internal drainage for pseudocysts.

RESULTS

The incidence of infection was 24% (8/33) for peripancreatic fluid collections and 59% (61/103) for patients with necrosis plus fluid collections or necrosis without fluid. Sixty-nine patients developed 25 gastrointestinal fistulas and 51 complications caused by pancreatic ductal disruption. Necrosis and infection but not the open packing technique were associated with increased risk of gastrointestinal fistulas. In patients with pancreatic ductal disruption, pancreatic fistulas developed following necrosectomy and external drainage, while pancreatic pseudocysts evolved from undrained peripancreatic fluid collections. Gastrointestinal fistulas required prompt operative intervention, whereas pancreatic ductal disruption was treated nonoperatively initially. The mortality rate was 13% (3/23) in patients with gastrointestinal fistulas, similar to the overall mortality rate of 10.3% (14/136). There was no mortality in patients with pancreatic fistulas or pseudocysts. Length of hospital stay was prolonged by the presence of necrosis and infection, not by gastrointestinal fistulas or ductal disruption. Thirty-eight of the 69 patients with these complications required readmission for operative management of their complications. To date, only 18 (13.2%) of 136 patients with severe pancreatitis have not required surgical intervention.

CONCLUSIONS

Gastrointestinal fistulas and pancreatic ductal disruption are common in severe pancreatitis. Although these complications are not associated with increased mortality or prolonged initial length of stay, readmission for elective surgical correction is necessary in most patients. Severe pancreatitis is a surgical disease, requiring both acute and long-term surgical care.

Therapeutic regimens in acute experimental pancreatitis in rats: effects of a protease inhibitor, a beta-agonist, and antibiotics

The osmolality of contrast injected retrograde into the rat pancreatic duct did not affect the severity of the pancreatitis (Urografin, 1,300 mOsm/kg, and Hexabrix, 580 mOsm/kg). The severity of the pancreatitis induced in rats was assessed by survival rate, histologic grading, wet lung ratio, and serum levels of amylase, lipase, and trypsin-like activity. Rats with pancreatitis induced by retrograde injected Urografin, lipopolysaccharide, taurocholic acid plus enterokinase were treated with either intravenous (i.v.) FUT-175 (Nafamstat Mesilate), FUT-175 administered by retrograde pancreatic injection, i.v. terbutaline, i.v. piperacillin sodium, piperacillin sodium by retrograde pancreatic duct injection, or a combination of FUT-175 plus terbutaline and piperacillin. Survival among the rats was increased and the incidence of pancreatic infection reduced in rats treated with i.v. piperacillin or with a combination of FUT-175 plus i.v. terbutaline, plus i.v. piperacillin compared to controls.

Local resection of the head of the pancreas combined with longitudinal pancreaticojejunostomy in the management of patients with chronic pancreatitis

OPERATION: Local resection of the head of the pancreas combined with longitudinal pancreaticojejunostomy of the body and tail of the pancreas (LR-LPJ) was designed to improve decompression of the head of the pancreas, which often was not drained well by standard longitudinal pancreaticojejunostomy. This was achieved by excising the head of the pancreas overlying the ducts of Wirsung and Santorini, and duct to the uncinate, along with their tributary ducts.

PATIENT MATERIAL

The operation has been performed on 50 patients. There were five late deaths among the 50 patients; two at 6 months, and one each at 24, 26, and 91 months. Eighty percent of the patients were alcoholics, 50% had pseudocysts, and 80% had calcification.

ASSESSMENT

Pain was assessed on a scale of 1 to 10, with 10 being most severe. Narcotic intake was considered minimal-Vicodin equivalent (hydrocodone bitartate, 5 mg, acetaminophen, 500 mg; Vicodin, Knoll Pharmaceuticals, Whippany, NJ) once or twice/month; moderate--Vicodin weekly daily; and major--meperidine hydrochloride (Demerol, Winthrop Pharmaceuticals, New York, NY) weekly or daily.

RESULTS

Pain relief in 47 patients was excellent (74.5%), improved in 12.75%, and unimproved in 12.75%. Endocrine status in 45 patients was as follows: 69% were not diabetic, and 20% were diabetic preoperatively and postoperatively. Postoperatively, 11% had progression of their diabetes. Exocrine function was not worsened and may have been improved in some patients. Sixty-four percent of 39 patients gained an average of 15.3 pounds. Fifty-nine percent of patients were not working preoperatively or postoperatively.

CONCLUSIONS

The LR-LPJ provides good pain relief with a modest increase in endocrine and exocrine insufficiency and a significant increase in weight. Even when relieved of pain, patients seldom return to the work force.

Role of fine needle aspiration cytology and endoscopic biopsy in the preoperative assessment of pancreatic and peripancreatic malignancies

Sixty-seven of 207 patients with pancreatic and peripancreatic malignancies underwent preoperative fine needle aspiration cytology (FNA), and 24 patients underwent intraluminal endoscopic biopsies. All patients had confirmation of the diagnosis of malignancy either at operation, autopsy, or by clinical follow-up. FNA of liver metastases was positive for malignancy in 12 of 12 patients. FNA of the pancreas was performed on 44 patients with pancreatic adenocarcinoma and 11 patients with other pancreatic or peripancreatic malignancies. The diagnosis of cancer was established by FNA in 32 of 44 (72.4%) patients with pancreatic adenocarcinoma and 1 of 11 patients (9.1%) with other pancreatic or peripancreatic malignancies. In the patients with pancreatic adenocarcinoma, 17 of 18 patients (94.4%) who had no operative intervention, 12 of 18 (66.7%) patients who had palliative bypass procedures, and 3 of 8 (37.5%) patients resected had positive FNA. Eighteen of 24 patients (75%) who underwent intraluminal endoscopic biopsies, and 11 of 15 (73.3%) with ampullary carcinoma were positive. We believe that FNA is of limited value in the diagnosis of small resectable tumors of the pancreas as it identified cancer in only 3 of 8 patients in whom it was employed. False negative FNA may delay the diagnosis and treatment of pancreatic malignancies. Patients in whom there is a high index of suspicion of pancreatic or peripancreatic malignancy based on clinical presentation, CT scan, or ERCP assessment do not require preoperative, histologic proof of malignancy prior to pancreaticoduodenectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Is there still a role for distal pancreatectomy in surgery for chronic pancreatitis?

The medical records of patients subjected to distal pancreatectomy for chronic pancreatitis from 1982 to 1992 were reviewed to ascertain if pain relief could be predicted based on computed axial tomography (CAT) and endoscopic retrograde cholangiopancreatography (ERCP) findings. Of 10 patients who had severe pain preoperatively and disease limited to the body or tail of the pancreas, 9 had no pain or only mild pain postoperatively. Of 7 patients with severe pain preoperatively and diffuse disease or disease localized to the head of the pancreas, 6 required further hospitalization and resection or drainage procedures for severe, recurrent pain. We believe 50% to 60% of distal pancreatectomy procedures meet most criteria for the best operation for a select group of patients with chronic pancreatitis: those patients with severe pain, small ducts (< 5 mm), and whose disease is limited to the body or tail of the gland.

Management of necrotizing pancreatitis

A comprehensive management plan is presented for patients with severe acute pancreatitis. These patients may have pancreatic or peripancreatic necrosis or pancreatic fluid collections. Multiple organ failure often develops in patients with severe pancreatitis. We therefore recommend that all patients with acute pancreatitis be evaluated for pancreatic anatomy and function. If a patient is seriously ill, a computed tomographic (CT) scan with vascular enhancement should be done. Meanwhile, vigorous fluid replacement is necessary using Swan-Ganz monitoring. Patients with necrosis do not need surgical intervention unless the clinical course or CT scan-guided aspiration shows infection. The objective of an operation should be to remove all infected tissue and fluid. A preoperative CT scan with vascular enhancement should be used as a guide during the operation to ensure that all foci of infected necrosis or fluid are eliminated. We have found that open packing and irrigation with sodium oxychlorosene are helpful in patients with extensive necrosis or those who become infected early after the onset of symptoms. In all, 40% to 50% of patients treated by closed drainage will require reoperation because of incomplete debridement. Persistent sepsis is an indication for reoperation.

Effect of preinjury illness on trauma patient survival outcome

Data from 11,156 patients treated at the four Major Trauma Outcome Study controlled sites were used to estimate the effect on survival of each APACHE II preinjury illness condition (PIC). A case-control methodology was applied; 544 patients (4.8%) had one or more PICs. For each patient with a specific PIC we identified a set of matching patients with no PICs. A patient matches a PIC patient if both have the same mechanism of injury, the same coding of Revised Trauma Score variables (Glascow Coma Scale score, systolic blood pressure, respiratory rate), the same coded age per A Severity Characterization of Trauma) (ASCOT), and if they differ by no more than 0.5 for A, B, and C (the ASCOT components for serious injuries). The estimated survival probability for a PIC patient is either the survival rate for the patient's matched set or, if there are no matches, the patient's ASCOT survival probability. The survival probabilities were used to compare the actual and predicted numbers of survivors for each PIC, using z and W statistics. Computations of z and W were also made using ASCOT survival probabilities for each PIC patient. The results indicate profound effects of five PICs (hepatic, cardiovascular, respiratory, renal, diabetes) on trauma patient outcomes.

CONCLUSION

Pre-existing organ dysfunction has a profound effect on patient outcome even after controlling for age, anatomic and physiologic severity, and mechanism of injury. But, because of their relatively low incidence in this sample, PICs did not strongly influence institutional outcome performance as measured by z and W values.

Role of bacterial infection in diet-induced acute pancreatitis in mice

This study was performed to elucidate the role of bacterial infection in acute pancreatitis in young female mice fed a choline-deficient diet supplemented with 0.5% DL-ethionine (CDE diet). Mice were randomly classified into two groups: one had been fed CDE diet alone (nonantibiotic group), the other was fed a CDE diet with oral administration of antibiotics (antibiotic group). Survival rates at 96 and 144 h after introduction of the CDE diet were significantly improved in the antibiotic group, 25.0 and 19.4%, respectively, as compared with 3.6 and 0% in the nonantibiotic group (p, 0.05). Aerobic and anaerobic bacterial cultures of blood, ascites, spleen, and pancreas were taken from living mice 72 h after introduction of the CDE diet. Positive bacterial growth from one or more of the specimens occurred in 29.4% of the nonantibiotic group, and in 10.0% of the antibiotic group. Mice with pancreatic necrosis had a higher positive culture rate, 62.5% in the nonantibiotic group vs 20.0% in the antibiotic group. These results suggest that reduction of intestinal flora in mice inhibits secondary infection caused by bacterial translocation and improves survival in diet-induced hemorrhagic pancreatitis. We believe the development of bacterial infection of gut origin may be a factor influencing mortality in severe pancreatitis.

Effect of protease inhibitor FUT-175 on acute hemorrhagic pancreatitis in mice

The effect of FUT-175, a new synthetic trypsin inhibitor, was evaluated in a lethal model of acute hemorrhagic pancreatitis induced by feeding mice a choline-deficient, ethionine-supplemented diet (CDE diet). When FUT-175 was given prophylactically at doses of 20 mg/kg body wt, the survival rate was significantly improved (p less than 0.05). The serum amylase concentration and trypsin activity in serum were also significantly diminished (p less than 0.05). Prophylactic administration of 5 mg/kg body wt of FUT-175 showed a statistically significant decrease in the serum trypsin activity, but it did not improve the survival rate. Therapeutic administration of FUT-175 showed no favorable effect. FUT-175 showed protective effects on the course of severe acute pancreatitis only when given prophylactically at the beginning of the pancreatitis induced by the CDE diet.

Endoscopic cholecystectomy. An analysis of complications

We analyzed our initial 381 endoscopic cholecystectomies with particular emphasis on postoperative complications. The rate of conversion to open cholecystectomy was 3%. A technical complication occurred in 2% and a non-technical complication in 4%, for a total complication incidence of 6%. There were three postoperative fatalities (0.9%). Two fatal technical complications consisted of unrecognized intestinal injuries at the time of endoscopic cholecystectomy that were obvious when the abdomen was opened. One patient died of a cerebrovascular accident. Nonfatal technical complications included five bile leaks that required treatment. There were no common bile duct injuries, but excessive caution to prevent common bile duct injury may have contributed to the high incidence of bile leaks. Examination of the case numbers of the technical complications and conversion to open cholecystectomy suggests that the learning curve is real and somewhat prolonged, and that a willingness to convert to open cholecystectomy is necessary if technical complications are to be avoided.

Classification of acute pancreatitis

Increased knowledge of the natural history, etiology, morphology, complications and systemic response of the patient to acute pancreatitis has led to a rapid evolution in the classification of acute pancreatitis. It is recommended that the following elements be included in a classification system of acute pancreatitis: 1. A definition of acute pancreatitis and its complications based on CT scan, ultrasound, ERCP, and angiographic and histologic findings. 2. A statement regarding the etiology of the patient's pancreatitis. 3. An assessment of the patient's systemic response to his or her pancreatitis by means of APACHE II and/or Ranson's signs of severity. This system, through the use of ultrasound, CT scan with vascular enhancement, and clinical and laboratory tests, can be utilized to classify patients initially, on the day of hospital admission, with regard to etiology, morphology, and physiologic severity. Later in their hospital course, the complications of pancreatitis, e.g., fluid collections, necrosis, pseudocysts, infected necrosis, abscesses, fistulas, pancreatic, enteric, and cutaneous, pseudoaneurysm, and splenic vein thrombosis, can be added to the classification as modifiers when and if they occur. The process of the development and confirmation of theories of the origin and nature of the cosmos and evolution of concepts regarding the classification of pancreatitis have something in common. Theory generally stimulates experimental observation whose purpose is to test the theory's validity. New theories are generated when experimental observations demonstrate inconsistencies in previously held beliefs. Just as our understanding of the cosmos is undergoing constant change based on new data and new theories, so are our concepts regarding the classification of pancreatitis.

The Major Trauma Outcome Study: establishing national norms for trauma care

The Major Trauma Outcome Study (MTOS) is a retrospective descriptive study of injury severity and outcome coordinated through the American College of Surgeons' Committee on Trauma. From 1982 through 1987, 139 North American hospitals submitted demographic, etiologic, injury severity, and outcome data for 80,544 trauma patients. Motor vehicle related injuries were most frequent (34.7%). Twenty-one per cent of patients had penetrating injuries. The overall mortality rate was 9.0%. The mortality rate for direct admissions was strongly related to the presence of serious head injury, 5.0% and 40.0%, when head injuries were less than or equal to AIS (Abbreviated Injury Scale) 3 or greater than or equal to AIS 4, respectively. Survival probability norms use the Revised Trauma Score, Injury Severity Score, patient age, and injury mechanism. Patients with unexpected outcomes were identified and statistical comparisons of actual and expected numbers of survivors made for each institution. Results provide a description of injury and outcome and support evaluation and quality assurance activities.

Comprehensive management of acute necrotizing pancreatitis and pancreatic abscess

Achieving reduced mortality rates in patients with necrotizing pancreatitis and pancreatic abscess is possible by employing a comprehensive management plan. Components of the plan include (1) rapid evaluation and assessment of the degree of physiologic and anatomic derangement, the latter by the prompt use of vascular enhanced computed tomographic scan; (2) adequate fluid resuscitation determined by early institution of advanced hemodynamic monitoring; (3) attempts to identify and document septic foci via computed tomography-guided percutaneous aspiration; and (4) aggressive surgical debridement. Close adherence to these policies allowed us to keep mortality in this seriously ill group of patients to 14%. Most deaths occurred in patients who were referred to this service late in the course of their disease. The Acute Physiology and Chronic Health Enquiry (APACHE) II severity of illness index applied at the time of admission proved an accurate predictor of mortality. A score of 25 or greater was highly predictive of death, and a lesser score, of survival.

Diagnosis and treatment of pancreatic injuries. An analysis of management principles

Ninety-one pancreatic injuries, 47 from blunt trauma, were reviewed with respect to management principles stressed in qi previous reviews. The pancreatic complication rate was 25%. Blunt injury was suspected preoperatively in only 30%. Even short-term observation led to morbidity. Operations done more than 6 hours after admission had a higher complication rate (45%) than those done less than 6 hours after admission (18%). Penrose drainage without a sump was not associated with increased complications. Distal pancreatectomy was done 32 times; splenectomy was done in only 18 patients. Individual duct ligation was rarely done and did not result in a high fistula rate. Pancreatic stump oversew with nonabsorbable suture was associated with a higher rate of pancreatic complications than absorbable suture (58% vs 30%). Only 56% of patients receiving distal pancreatectomy required hyperalimentation. Postoperative serum amylase values were not useful, and amylase values from drainage fluid predicted complications only when they were above 100,000 U/L. Details of pancreatic trauma management are less important than early operation in minimizing morbidity.

Pancreatitis after endoscopic retrograde cholangiopancreatography. An underreported disease whose severity is often unappreciated

We describe our experience between 1985 and 1989 with 24 patients with clinically significant pancreatitis after endoscopic retrograde cholangiopancreatography. The resulting pancreatitis was categorized into three groups, all requiring hospitalization: (1) mild pancreatitis (n = 12); (2) moderate pancreatitis requiring aggressive evaluation, treatment, and follow-up (n = 6); and (3) severe pancreatitis requiring surgical therapy (n = 6). The average length of hospitalization for the entire group was 12.8 days. Surgical intervention was required in 5 patients, and 3 patients died of acute necrotizing pancreatitis with sepsis, adult respiratory distress syndrome, and intractable hemodynamic failure. Our experience with this entity suggests that this form of pancreatitis includes severe and even lethal outcomes. It was associated with a mortality of 13%.

Treatment of chronic pancreatitis complicated by obstruction of the common bile duct or duodenum

In patients with chronic pancreatitis, common bile duct obstruction is reported in 3.2-45.6% of patients; however, only 5-10% of all patients with chronic pancreatitis require operative decompression of the bile duct. The cause of the intrapancreatic stricture of the common bile duct may be either a fibrotic inflammatory restriction, or compression by a pseudocyst. Obstruction of the duodenum is much less common than common bile duct obstruction in chronic pancreatitis occurring in less than 1-2% of patients with chronic pancreatitis. Colonic obstruction secondary to pancreatitis is very infrequent. The intrapancreatic strictures of chronic pancreatitis are characteristically smooth and tapering on endoscopic retrograde cholangiopancreatography (ERCP), but in some patients, they may have a sharp cut-off and closely resemble the appearance of carcinoma of the pancreas invading the bile duct. The natural history of these intrapancreatic strictures is variable. They may progress and be associated with cholangitis, biliary cirrhosis, common duct stones, or may remain stable for years or regress. Prior pancreaticojejunostomy is not protective against the development of intrapancreatic biliary strictures which may follow in 5-30% of patients, with most authors reporting an incidence of less than 10%. Evaluation of alkaline phosphatase, bilirubin, the presence of jaundice, or the appearance of an intrapancreatic stricture on ERCP is not predictive of whether cholangitis or biliary cirrhosis may or may not develop. The incidence of cholangitis and biliary cirrhosis in patients with intrapancreatic stricture is 9.4% and 7.3%, respectively. Laennec's cirrhosis occurs in a similar number of patients. Operation is indicated in patients with intrapancreatic strictures of the common bile duct in association with chronic pancreatitis in patients developing cholangitis, biliary cirrhosis, common duct stones, progression of the stricture, persistent high elevations of alkaline phosphatase and/or bilirubin for over a month or inability to rule out cancer of the pancreas or periampullary region. The operation of choice is choledochoduodenostomy or Roux-en-Y choledochojejunostomy to bypass the obstructed intrapancreatic portion of the common bile duct. Persistent duodenal obstruction for over 3 or 4 weeks is an indication for gastrojejunostomy. Pain is not a feature of common bile duct obstruction in the absence of cholangitis. In the presence of pain associated with chronic pancreatitis, longitudinal pancreaticojejunostomy is the operation of choice combined with Roux-en-Y choledochojejunostomy. Some of the newer operations, e.g., the Beger and Frey procedures, may make the necessity of a separate operation for biliary decompression superfluous.

Pancreatic resection for chronic pancreatitis

Patients with chronic pancreatitis needing operative management include those with severe pain, those with complications of pancreatitis, or those in whom it is not possible to distinguish cancer of the pancreas from chronic pancreatitis. The use of endoscopic retrograde cholangiopancreatography, CT, and angiography to define the structural abnormalities has increased the surgeon's ability to select an operation matched to the patient's needs. A longitudinal pancreaticojejunostomy should be performed in patients whose ducts are dilated. When the head of the pancreas is enlarged and thickened, pancreaticoduodenectomy has been the traditional operation of choice. However, local resection with pyloric and duodenal preservation should now be considered an alternative that has a lower mortality rate and less likelihood of creating diabetes or exocrine insufficiency. Patients whose ducts are of insufficient caliber to permit longitudinal pancreaticojejunostomy are candidates for resection of the proximal or distal pancreas, depending on the site of disease or, alternatively, for the Beger or Warren procedure. Pain relief is achieved with surgery in about 80 per cent of patients with chronic pancreatitis. Many of the late deaths following operation for chronic pancreatitis are attributable, not to the operation, but to the effects of alcoholism. There is a need for surgeons to improve their observations and assessment of operative results.

Liver abscesses

Clinical suspicion of a liver abscess mandates an investigation of the liver for evidence of a liver abscess by radionuclide, ultrasound, or CT scan. Amebic abscesses have a lower mortality rate than pyogenic abscesses. Amebic and pyogenic abscesses can be distinguished on the basis of epidemiologic, clinical, and laboratory studies. The definitive studies for identifying amebic liver abscesses are hemagglutinin or gel diffusion studies. Amebic abscess of the liver may be complicated by extension to the lung, with pulmonary complications. Patients suspected to have amebic abscesses require metronidazole. Emetine or chloroquine may be added if there is no response or if the abscess recurs. Unless there is a failure of the amebic abscess to resolve or secondary infection occurs, there is seldom a need to aspirate or drain these abscesses. Pyogenic abscesses should be treated with broad-spectrum antibiotics to cover gram-negative aerobes and anaerobic organisms. All pyogenic abscesses larger than 1.5 cm in diameter should be aspirated, and the aspirate should be Gram stained and cultured. Percutaneous or surgical drainage should then be performed. Operative intervention is required in those patients with intra-abdominal pyogenic infections that are seeding the liver abscess. The marked reduction in the mortality rate of pyogenic liver abscess witnessed in this decade is multifaceted and attributable in part to earlier diagnosis, permitting definitive treatment in a timely fashion, as well as to improved intensive unit care, antibiotic management, and operative technique.