Blood Transfusion

Over the 6‑month period covering April 2010 to September 2010, all patients admitted to one of our patient wards at the Division of General Surgery, Department of Surgery, Medical University of Vienna were included in this study.
The Division of General Surgery in our university hospital consists of the following teams and specializations: colorectal surgery, hepatobiliary surgery, endocrine surgery, upper gastrointestinal (GI) surgery (esophageal and stomach surgery), bariatric surgery, breast surgery, and pancreatic surgery.
The patient data were extracted by reviewing all discharge letters from that period taken from the digital archives.
Overall, 517 patients were admitted over this period, some repeatedly, leading to a total of 817 admissions. These 517 patients underwent 463 operations. The complications of these operations were then rated according to the Clavien-Dindo classification (Table 1). For easier use, the suffix “d” for permanent disability was not drawn upon.Table 1

Clavien-Dindo classification

Grade	Definition
Grade I	Any deviation from the normal postoperative course without the need for pharmacological treatment, or surgical, endoscopic, and radiological interventions.Allowed therapeutic regimens are: drugs as antiemetics, antipyretics, analgetics, diuretics and electrolytes, and physiotherapy. This grade also includes wound infections opened at the bedside
Grade II	Requiring pharmacological treatment with drugs other than such allowed for grade I complications.Blood transfusions and total parenteral nutrition are also included
Grade III	Requiring surgical, endoscopic, or radiological intervention
Grade IIIa	Intervention not under general anesthesia
Grade IIIb	Intervention under general anesthesia
Grade IV	Life-threatening complication (including central nervous system complications) requiring IC/ICU management
Grade IVa	Single organ dysfunction (including dialysis)
Grade IVb	Multiorgan dysfunction
Grade V	Death of a patient

According to Dindo et al. [6 (link)]

IC intermediate care, ICU intensive care unit

The operations were sorted according to the complexity ranking (eight groups) in the accounting system of the Austrian Chamber of Physicians (Table 2; [8 ]).Table 2

Operation groups (complexity according to the Austrian Chamber of Physicians)

Operation group	Examples
I	Abscess incisions, secondary sutures, proctoscopy, skin biopsy
II	Excisions of atheromas, fibromas, lipomas, incisions of anal abscesses
III	Toe amputation, small lymph node extirpation, thoracic drainage, colonoscopy
IV	Tracheotomy, appendectomy, hernia operation, colostomy, gastrostomy, ERCP
V	Gastroenterostomy, interventions for recurrent hernia, Cimino fistula, radical varicose vein stripping
VI	Strumectomy, cholecystectomy, splenectomy, hemicolectomy, reduction mammoplasty
VII	Partial pancreatectomy, subtotal colectomy, subsegmental and large liver resections
VIII	Esophageal resection, open surgery of aortic aneurysms, organ transplantation

Technical success was defined as the successful use of AngioJet RT. Thrombus score was calculated through venography imaging by two experienced interventional physicians independently depending on pre-RT, at the completion of RT or post-CDT, by adding the scores of six vein segments (common iliac vein, external iliac vein, common femoral vein, proximal and distal segments of femoral vein, and popliteal vein). Thrombus scores were 0 when the vein was patent and completely free of thrombus, 1 in condition of a partially occluded vein, and 2 in condition of a completely occluded vein (i.e., vein lumen completely occluded with massive thrombus). The score was calculated for each segment, resulting in possible total thrombus scores. The thrombus removal rate was calculated as follows: [total pre-RT scores - total completion of RT (or total post-CDT scores)]/total pre-RT scores × 100%. Thrombus removal grades were evaluated as grade III (100% thrombus removal rate with no residual clots), grade II (50–99% thrombus removal rate), and grade I (< 50% thrombus removal rate). Thrombus removal grades II and III (i.e., ≥50% thrombus removal rate) were considered clinical success [10 (link)], which consisted of primary RT success and adjunctive CDT success. The primary RT (defined as patients who did not require adjunctive CDT treatment) success was classified based on preprocedural and at completion of RT thrombus scores evaluated as grade II and grade III. Adjunctive CDT (defined as patients who required adjunctive CDT treatment) success was classified based on preprocedural thrombus scores and those at the end of adjunctive CDT that were evaluated as grade II and grade III. The requirement of necessary adjunctive PTA and/or stent placement to treat coexisting stenosis to obtain sufficient flow within the same hospital stay was recorded but not considered clinical failure.
The safety outcomes consisted of procedure-related and CDT-related complications. The former included vessel perforation or damage (such as extravasation or retention of contrast agent in the vessel wall), bradycardia, arrhythmias or acute kidney injury (AKI). With adherence to the Society of Interventional Radiology (SIR) [11 (link)], the latter feature was divided into major CDT-related complications, which were defined as intracranial bleeding or bleeding severe enough to result in death, surgery, cessation of therapy, or blood transfusion, and minor complications, which were defined as less severe bleeding manageable with local compression, sheath upsizing, and/or alterations of thrombolytic agent dose and anticoagulant dose [11 (link)]. The SIR classification of complications is listed in the Supplementary Table.

For the active cohort, the epidemiological variables studied were sex (referring to, throughout the manuscript, as ‘sex assigned at birth’; male or female), year of HIV diagnosis, age at HIV diagnosis, age at data extraction (December 2020), mode of HIV acquisition (sexual, transfusion of blood products, vertical transmission, or people who inject drugs) and place of birth (Spain, rest of Europe, Africa, Latin America, United States, Asia, or unknown).
Laboratory, antiretroviral and clinical data were only analysed for a subset of the active cohort starting 1990. Indeed, in patients diagnosed with HIV before 1990, missing data on the baseline CD4⁺ cell count, HIV viral load, and antiretroviral treatment (ART) were frequent occurrences; hence, the period from 1 January 1982 to December 1989 was excluded from analysis. Moreover, for patients transferred to Hospital Clínic from other centres, the baseline CD4⁺ cell count and HIV viral load were not always reported in the electronic records; therefore, for data accuracy, laboratory, antiretroviral and clinical data were analysed only for treatment-naïve HIV patients visiting in our hospital, i.e. patients who had never started ART in other centres before being transferred or before their first visit to our hospital.
The laboratory parameters taken into account were the CD4⁺ cell count (cells/mm³) at diagnosis, nadir CD4⁺ cell count (cells/mm³), and HIV viral load (copies/mL) at diagnosis. Late diagnosis was defined as CD4⁺ cell count  < 350 cells/mm³ at diagnosis. In relation to treatment, we analysed the type of ART regimen at the initiation of treatment, number of changes in ART during the follow-up, and virological suppression and virological failure after the initiation of ART. Virological failure was defined as two consecutive viral loads of > 50 copies/mL after achieving viral suppression.