Comparison of efficacy of three gases for anterior chamber tamponade in Descemet's membrane endothelial keratoplasty.

PURPOSE: To compare the efficacy of three different gases for intraocular tamponade: 100% air, 10% perfluoropropane (C3F8), and 10% sulfur hexafluoride (SF6), in Descemet's membrane endothelial keratoplasty (DMEK). MATERIALS AND METHODS: The medical records of 138 patients who underwent DMEK were reviewed retrospectively, with the primary outcome being the rebubbling rate in the first week following surgery. Other clinical outcomes, such as best-corrected visual acuity (BCVA), central corneal thickness (CCT), incidence of rebubbling after the first week, endothelial cell density (ECD), graft detachment, graft failure, pupillary block, and intraocular pressure (IOP) changes were also analyzed. RESULTS: Of the 138 patients, 57 were in group 1 (treated with air), 44 in group 2 (treated with 10% C3F8), and 37 in group 3 (treated with 10% SF6). Group 3 showed significantly lower rates of graft detachment and rebubbling compared to groups 1 and 2 (P<0.001). However, there was no significant difference in postoperative BCVA among the groups. At one year, the mean endothelial cell loss was 32% in group 1, 30% in group 2, and 33% in group 3 (P=0.715). One patient in group 1 experienced pupillary block and increased IOP, while there were no such occurrences in the other groups. There was no difference between the groups in terms of graft failure. CONCLUSION: The use of 10% SF6 in DMEK surgery may be a good option due to its efficacy in preventing graft detachment, low rebubbling rate, and potential for minimizing complications.

Effect of sodium-glucose co-transporter-2 inhibitors on coronary blood flow in patients with type 2 diabetes mellitus.

OBJECTIVE: Type 2 diabetes mellitus (T2DM) is known to be associated with endothelial dysfunction (ED). Reducing ED can attenuate the occurrence of cardiovascular diseases. One of the indicators of ED is decreased coronary blood flow (CBF). Sodium-glucose co-transporter 2 inhibitors (SGLT-2is) are known to directly improve ED in both euglycemic and hyperglycemic conditions and have been shown to decrease the incidence of major cardiovascular events. We aimed to investigate whether SGLT-2is improves CBF in patients with T2DM, who have angiographically normal or nearly normal coronary arteries. PATIENTS AND METHODS: In this single-center retrospective study, all patients who underwent coronary angiography between January 2017 and September 2022 were screened. We designed the study by dividing the patients into two groups - those who used conventional antidiabetic medications (CAM) together with SGLT-2is (patients using an SGLT-2 inhibitor for at least 3 months) and those who used only conventional antidiabetic medications. Of the 18,205 patients who underwent coronary angiography, 5,040 patients had T2DM. After exclusion, 288 patients were divided into two groups - those who used CAM together with SGLT-2is and those who used only CAM. CBF was assessed by thrombolysis in myocardial infarction (TIMI) frame counting. RESULTS: Two hundred eighty-eight patients who had T2DM and met the inclusion criteria were included in our study. The patients were divided into two groups - those who used CAM together with SGLT-2is (n = 75) and those who used only CAM (n = 213). The median age in the group that used CAM together with SGLT-2is was 55 (51-64), where 52 (69.3%) patients were female. The mean TIMI frame count (TFC) was 23.5 in the group using CAM + SGLT-2is and 27.5 in the group using only CAM. In the multivariable linear regression analysis, the mean TFC was significantly lower in the group using CAM together with SGLT-2is compared to the group using only CAM [ß-coefficient = -12.766, 95% Cl: -5.304; -3.887, p < 0.001]. Moreover, there was a statistically significant correlation between an increase in BMI and hemoglobin with an increase in the mean TFC [ß-coefficient = 3.018, 95% Cl 0.037-0.175, p = 0.003 and ß-coefficient = 2.316, 95% Cl 0.033-0.405, p = 0.021, respectively]. CONCLUSIONS: We have demonstrated that the use of SGLT-2is improves coronary artery blood flow in patients with T2DM who have normal or nearly normal coronary angiography.

Evaluation of the effect of bun/albumin ratio on in-hospital mortality in hypertensive COVID-19 patients.

OBJECTIVE: The impact of COVID-19 infection still continues all over the world and is an important cause of mortality. The mortality rate due to infection varies between 1-5%. The mortality rate is higher in those with cardiovascular risk factors, especially in cases with hypertension. Some studies have shown that blood urea nitrogen (BUN) and albumin levels are associated with worse prognosis in patients with COVID-19. In our study, we aimed to investigate whether the BUN/albumin (BAR) ratio has an effect on in-hospital mortality in hypertensive COVID-19 patients. PATIENTS AND METHODS: A total of 800 hypertensive COVID-19 patients, (618 of whom were alive and 182 died) were included in our study. Patients with a history of heart failure, malignancy, acute coronary syndrome, and myocarditis were excluded. RESULTS: The median age of the study population was 69 (60-77 IQR) years, and 305 (38%) of these patients were men. There was no statistically significant difference between the patients who died during follow-up and cases that remained alive in terms of comorbidities except chronic obstructive pulmonary disease (COPD) which was significantly lower in surviving group (p=0.014). Multivariable logistic regression analysis revealed that age [OR: 1.04, CI (1.01-1.06); p=0.002], male gender [OR: 1.85, CI (1.13-3.02); p=0.010], lymphocyte count [OR: 0.63, CI (0.40-0.98); p=0.038], SaO2 [OR: 0.82, CI (0.79-0.85); p<0.001] and BAR level [OR: 1.09, CI (1.04-1.16); p=0.001] were independent predictors of in-hospital mortality. ROC analysis yielded that BAR is a better predictor of in-hospital mortality compared to albumin and BUN alone. CONCLUSIONS: BUN, albumin, and BAR levels were found to be reliable predictors of in-hospital mortality in COVID-19 patients, and BAR was also found to be a more reliable predictor than BUN and albumin levels. Hypertension is one of the major risk factors for morbidity and mortality in COVID-19 and, BAR presents additional prognostic data in hypertensive COVID-19 patients that may direct physicians for treatment intensification.

High-density SNP assay development for genetic analysis in maritime pine (Pinus pinaster).

Maritime pine provides essential ecosystem services in the south-western Mediterranean basin, where it covers around 4 million ha. Its scattered distribution over a range of environmental conditions makes it an ideal forest tree species for studies of local adaptation and evolutionary responses to climatic change. Highly multiplexed single nucleotide polymorphism (SNP) genotyping arrays are increasingly used to study genetic variation in living organisms and for practical applications in plant and animal breeding and genetic resource conservation. We developed a 9k Illumina Infinium SNP array and genotyped maritime pine trees from (i) a three-generation inbred (F2) pedigree, (ii) the French breeding population and (iii) natural populations from Portugal and the French Atlantic coast. A large proportion of the exploitable SNPs (2052/8410, i.e. 24.4%) segregated in the mapping population and could be mapped, providing the densest ever gene-based linkage map for this species. Based on 5016 SNPs, natural and breeding populations from the French gene pool exhibited similar level of genetic diversity. Population genetics and structure analyses based on 3981 SNP markers common to the Portuguese and French gene pools revealed high levels of differentiation, leading to the identification of a set of highly differentiated SNPs that could be used for seed provenance certification. Finally, we discuss how the validated SNPs could facilitate the identification of ecologically and economically relevant genes in this species, improving our understanding of the demography and selective forces shaping its natural genetic diversity, and providing support for new breeding strategies.

Head and neck malignant melanoma: local recurrence rate following wide local excision and immediate reconstruction.

Excision of head and neck melanoma is often limited by critical structures, which can lead to incomplete excision with positive pathologic margin and increased local recurrence rate. Complete excision with recommended margins and immediate reconstruction is possible when surgical oncologists and plastic surgeons work collaboratively. Our purpose was to evaluate local recurrence rate after excision and immediate reconstruction. We reviewed 98 consecutive patients treated for primary head and neck cutaneous melanoma at a single institution between 1999 and 2004. We assessed local recurrence rate. A total of 72 patients (73%) were followed for an average of 5.2 ± 1.7 years while 26 patients were excluded due to less than 1 year of follow-up. Adjacent tissue transfer was the most common reconstruction (87%). Local recurrence was reported in 2.8% and distant metastasis in 12.5% of patients. Immediate reconstruction after excision of head and neck melanoma can be safely performed with low local recurrence rate.

An alternative method of fabricating a custom tray for direct implant impressions.

Creating accurate impressions for implants is essential for fabricating passive-fitting prostheses. This report describes a modified technique for fabricating a custom impression tray when implants are positioned unfavorably. A simple and accurate method of making an implant impression tray and the benefits of this technique are highlighted in this technical report.

Protective effects of black cumin (Nigella sativa) oil on TNBS-induced experimental colitis in rats.

BACKGROUND: The pathogenesis and treatment of ulcerative colitis remain poorly understood. The aim of the present study is to investigate the effects of black cumin (Nigella sativa) oil on rats with colitis. METHODS: Experimental colitis was induced with 1 mL trinitrobenzene sulfonic acid (TNBS) in 40% ethanol by intracolonic administration with 8-cm-long cannula under ether anesthesia to rats in colitis group and colitis + black cumin oil group. Rats in the control group were given saline at the same volume by intracolonic administration. Black cumin oil (BCO, Origo "100% natural Black Cumin Seed Oil," Turkey) was given to colitis + black cumin oil group by oral administration during 3 days, 5 min after colitis induction. Saline was given to control and colitis groups at the same volume by oral administration. At the end of the experiment, macroscopic lesions were scored and the degree of oxidant damage was evaluated by colonic total protein, sialic acid, malondialdehyde, and glutathione levels, collagen content, and tissue factor, superoxide dismutase, and myeloperoxidase activities. Tissues were also examined by histological and cytological analysis. Proinflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, and IL-6], lactate dehydrogenase activity, and triglyceride and cholesterol levels were analyzed in blood samples. RESULTS: We found that black cumin oil decreased the proinflammatory cytokines, lactate dehydrogenase, triglyceride, and cholesterol, which were increased in colitis. CONCLUSIONS: BCO, by preventing inflammatory status in the blood, partly protected colonic tissue against experimental ulcerative colitis.

Mesenchymal stem cells induce dermal fibroblast responses to injury.

Although bone marrow-derived mesenchymal stem cells have been shown to promote repair when applied to cutaneous wounds, the mechanism for this response remains to be determined. The aim of this study was to determine the effects of paracrine signaling from mesenchymal stem cells on dermal fibroblast responses to injury including proliferation, migration and expression of genes important in wound repair. Dermal fibroblasts were co-cultured with bone marrow-derived mesenchymal stem cells grown in inserts, which allowed for paracrine interactions without direct cell contact. In this co-culture model, bone marrow-derived mesenchymal stem cells regulate dermal fibroblast proliferation, migration and gene expression. When co-cultured with mesenchymal stem cells, dermal fibroblasts show increased proliferation and accelerated migration in a scratch assay. A chemotaxis assay also demonstrated that dermal fibroblasts migrate towards bone marrow-derived mesenchymal stem cells. A PCR array was used to analyze the effect of mesenchymal stem cells on dermal fibroblast gene expression. In response to mesenchymal stem cells, dermal fibroblasts up-regulate integrin alpha 7 expression and down-regulate expression of ICAM1, VCAM1 and MMP11. These observations suggest that mesenchymal stem cells may provide an important early signal for dermal fibroblast responses to cutaneous injury.

Substance P enhances wound closure in nitric oxide synthase knockout mice.

INTRODUCTION: The neuropeptide, substance P (SP), up-regulates nitric oxide production (NO). The purpose of this study was to determine whether SP enhances response to cutaneous injury in nitric oxide synthase knockout (NOS null) mice. METHODS: We studied mice with targeted deletions of the 3 NOS genes, neuronal NOS, inducible NOS, or endothelial NOS. Full thickness dorsal wounds were treated daily (d 0-6) with topical SP or normal saline (NaCl). Wounds were analyzed by flow cytometry for macrophage, leukocyte, endothelial, and dendritic cells. Healing time and wound epithelialization were compared using analysis of variance. RESULTS: Wound closure in the 3 NOS null mice was slower than the control mice (P < 0.05). SP treatment enhanced wound closure in NOS null mice (P < 0.02). NOS null wounds exhibited reduced inflammation. SP increased macrophage, leukocyte, and dendritic cell densities at d 3 and d 7 (P < 0.05) in all NOS null mice. SP increased endothelial cell number in neuronal NOS and inducible NOS null mice, but not in endothelial NOS null mice (P > 0.05). CONCLUSIONS: SP ameliorated the impaired wound healing response observed in NOS null mice by enhancing wound closure kinetics and epithelialization. SP increased inflammatory cell density in the wounds supporting the essential role of inflammatory cells, especially macrophages, in wound repair.

Patient body mass index and perforator quality in abdomen-based free-tissue transfer for breast reconstruction.

Body mass index (BMI) must be considered when selecting patients suitable for abdomen-based microsurgical breast reconstruction. It is unknown whether BMI or age affects quality or quantity of abdominal wall perforating blood vessels. The purpose of this study was to identify differences in abdominal wall perforating blood vessels among patients with different BMI and age. A retrospective review was conducted of 66 patients undergoing abdomen-based microsurgical breast reconstruction tissue transfer from 2000 to 2006. Median age was 48.6 years (+/- 8.2). Patients were divided into BMI < 25 (28 patients), BMI 25 to 30 (26 patients), or BMI > 30 (12 patients). Perforator size and location was determined by ultrasound data. There was a greater number of perforators in horizontal zone II compared with the remaining zones (P < 0.05, Bonferroni corrected). There were no differences between age or BMI and the number of perforators or average perforator size per patient. A significant positive linear association was found between the average perforator diameter and total number of abdominal wall perforators. We concluded there is no anatomical difference in perforator quality among patients with varying BMIs

True incidence of all complications following immediate and delayed breast reconstruction.

BACKGROUND: Improved self-image and psychological well-being after breast reconstruction are well documented. To determine methods that optimized results with minimal morbidity, the authors examined their results and complications based on reconstruction method and timing. METHODS: The authors reviewed all breast reconstructions after mastectomy for breast cancer performed under the supervision of a single surgeon over a 6-year period at a tertiary referral center. Reconstruction method and timing, patient characteristics, and complication rates were reviewed. RESULTS: Reconstruction was performed on 240 consecutive women (94 bilateral and 146 unilateral; 334 total reconstructions). Reconstruction timing was evenly split between immediate (n = 167) and delayed (n = 167). Autologous tissue (n = 192) was more common than tissue expander/implant reconstruction (n = 142), and the free deep inferior epigastric perforator was the most common free flap (n = 124). The authors found no difference in the complication incidence with autologous reconstruction, whether performed immediately or delayed. However, there was a significantly higher complication rate following immediate placement of a tissue expander when compared with delayed reconstruction (p = 0.008). Capsular contracture was a significantly more common late complication following immediate (40.4 percent) versus delayed (17.0 percent) reconstruction (p < 0.001; odds ratio, 5.2; 95 percent confidence interval, 2.3 to 11.6). CONCLUSIONS: Autologous reconstruction can be performed immediately or delayed, with optimal aesthetic outcome and low flap loss risk. However, the overall complication and capsular contracture incidence following immediate tissue expander/implant reconstruction was much higher than when performed delayed. Thus, tissue expander placement at the time of mastectomy may not necessarily save the patient an extra operation and may compromise the final aesthetic outcome.

Topical substance P increases inflammatory cell density in genetically diabetic murine wounds.

The neuropeptide substance P (SP) is a known inflammatory mediator released from cutaneous peripheral nerve terminals. SP effects on cellular composition in the cutaneous response to injury remain unclear. Based on our previous observations about SP effects on wound repair, we hypothesized that topical SP increases inflammatory cell density infiltration early after injury. A full-thickness 1.5 x 1.5 cm(2) wound was created on the dorsum of 8-9-week-old C57BL/6J-m+Lepr(db) mice (db/db). Wounds were treated daily with 300 muL of either normal saline (0.9% NaCl) or 10(-9) M SP for 7 days. Three wounds from each group were harvested at 2, 3, 7, 14, and 28 days. Samples underwent enzymatic digestion and were incubated with fluorescent-labeled antibodies. Using flow cytometry, cellular content and density for each sample was derived. Masson Trichrome stained histology specimens were prepared to confirm results. Cell density in the SP-treated wounds (11.3 x 10(7) cells/g tissue, standard deviation [SD]+/-1.5 x 10(7)) was greater than in NaCl-treated wounds (7 x 10(7) cells/g tissue, SD+/-2.3 x 10(7), p<0.05) at day 7 postwounding. SP significantly increased the density of leukocytes (2.1 x 10(7), SD +/-3.6 x 10(6) vs. 1.8 x 10(7), SD+/-4.9 x 10(5), p<0.02) 3 days after wounding and the density of macrophages (2.9 x 10(7), SD+/-7.5 x 10(6) vs. 1.3 x 10(7), SD+/-1.4 x 10(6), p<0.05) 7 days after wounding. There were no significant differences in endothelial cell, leukocyte, or macrophage density at later time points. Topical SP treatment increases early inflammatory density in the healing wounds of db/db mice. These data support a role for nerve-mediated inflammation in cutaneous wound repair.

Resection of panniculus morbidus: a salvage procedure with a steep learning curve.

BACKGROUND: A subset of obese people develop a pannus hanging to the floor. This panniculus morbidus prevents weight loss, as the patient cannot exercise. It prevents hygiene, leading to a profound odor and ultimately results in intertrigo, cellulitis, and/or abdominal ulceration. The only two options are to live/die with it or resect it. Some of these people are otherwise ready for a weight loss program. For this group, resection of the panniculus morbidus may be indicated. The authors reviewed the literature and found the condition has not been addressed in this Journal since 1994 and was not considered in the recent supplement on body contouring. In 1998, the authors began resecting panniculus morbidus for this small group. The authors found the learning curve to be profoundly steep, with many wound complications, a finding that is quite in conflict with the literature on the subject, and decided to present their experience. METHODS: The authors conducted a retrospective chart review of 23 patients and collected data on demographics, ambulation, hygiene, technique, complications, and outcome. RESULTS: The technique of closure evolved as the authors struggled with complications. The current method of closure is three suture layers over four suction drains with a small wound vacuum-assisted closure device at each end of the incision. All patients ultimately healed and found it easier to ambulate and perform hygiene. CONCLUSION: Resection of panniculus morbidus is a beneficial salvage procedure for some morbidly obese people, but the learning curve is steep and the current literature is misleading.

Review of the female Duroc/Yorkshire pig model of human fibroproliferative scarring.

Hypertrophic scarring after burns is an unsolved problem and remains as devastating today as it was in the 40s and it may be that the main reason for this is the lack of an accepted, useful animal model. The female, red Duroc pig was described as a model of hypertrophic scarring nearly 30 years ago but then vanished from the literature. This seemed strange since the authors reported that 12 of 12 pigs developed thick scar. In the mid 90s we explored the model and found that, indeed, the red Duroc pig does make thick scar. Other authors have established that the Yorkshire pig does not heal in this fashion so there is the possibility of a same species control. We have continued to explore the Duroc/Yorkshire model and herein describe our experiences. Is it a perfect model of hypertrophic scarring? No. Is it a useful model of hypertrophic scarring? Time will tell. We have now obtained gene expression data from the Duroc/Yorkshire model and analysis is underway.

Breast implant capsules are partially composed of bone marrow-derived cells.

Capsular contracture is the most common complication following breast augmentation or reconstruction with implants. We recently demonstrated that bone marrow-derived cells provide fibroblasts to murine skin during wound healing. To determine if bone marrow-derived cells were the cellular source of periprosthetic capsules, we created chimeric C57BL mice containing bone marrow cells from isogeneic enhanced green fluorescent protein (EGFP) mice and implanted with a textured silicone shell implant. We found that none of the mice developed infection or capsular contracture, but day 30 capsules were composed of 26.4 +/- 6.1% EGFP cells, and day 60 capsules had 21.8 +/- 10.3% EGFP cells. Immunohistochemistry revealed a small population of EGFP cells in the capsules that were myofibroblasts. Thus, breast implant capsules are partially composed of bone marrow-derived cells and, given the potential of these cells to become myofibroblasts, may explain the cellular source of capsular contracture when it develops.

Utility of the free deep inferior epigastric perforator flap in chest wall reconstruction.

Breast cancer chest wall recurrence is often treated with chemotherapy, radical surgery, and radiation. Extensive chest wall resection requires soft-tissue reconstruction with tissue that provides chest wall stability and durability for additional radiation. Local and regional muscle and musculocutaneous flaps are often used for reconstruction. Free flaps, such as the transverse rectus abdominis musculocutaneous flap, are used for large defects, although donor site morbidity can result. The free deep inferior epigastric perforator (DIEP) flap provides coverage for large defects and may have less donor site morbidity. We describe the use of the free DIEP flap to reconstruct large chest wall defects (mean, 501 cm2 defects) after the resection of recurrent breast cancer in two patients. One patient had 2% flap loss. No donor site morbidity occurred. The free DIEP flap is a durable and reliable flap that provided immediate and complete coverage of these large chest wall defects with no donor site morbidity and did not delay the administration of adjuvant therapy.

Histology of the thick scar on the female, red Duroc pig: final similarities to human hypertrophic scar.

The etiology and treatment of hypertrophic scar remain puzzles even after decades of research. A significant reason is the lack of an accepted animal model of the process. The female, red Duroc pig model was described long ago. Since the skin of the pig is similar to that of humans, we are attempting to validate this model and found it to be encouraging. In this project we quantified myofibroblasts, mast cells and collagen nodules in the thick scar of the Duroc pig and compared these to the values for human hypertrophic scar. We found the results to be quite similar and so further validated the model. In addition, we observed that soon after wounding an inflammatory cell layer forms. The thickness of the inflammatory layer approaches the thickness of the skin removed as if the remaining dermis "knows" how much dermis is gone. In deep wounds this inflammatory layer thickens and this thickness is predictive of the thickness of the ultimate scar.

Does the use of a flap during abdominoperineal resection decrease pelvic wound morbidity?

We hypothesized that the use of muscle flaps, known as tissue transfer (TT), at the time of abdominoperineal resection (APR) reduces perineal wound complications. A restrospective review of patients undergoing an APR at the University of Washington (1984-2003) was conducted. Perineal wound complications and eventual wound healing were compared in patients with and without TT. Ninety-two patients (mean age, 56.6 years) underwent APR; 23.9 per cent (n = 22) had concurrent TT. Patients undergoing TT were more likely to have cancer (91% vs. 77%, P = 0.05) and radiation therapy (86% vs. 52%, P < 0.01). Operative times were nearly 2 hours longer in patients having TT (7.4 hours +/- 2.5 hours vs. 5.6 hours +/- 1.8 hours, P = 0.03), but lengths of stay were similar (13 +/- 5.9 days vs. 12 +/- 7.6 days, P = 0.5). Patients undergoing TT had a higher rate of all wound-healing complications (59% vs. 40%, P = 0.1) and major wound-healing complications (32% vs. 26%, P = 0.6). However, these differences were not statistically significant. No differences in major complications were identified in patients with and without preoperative radiation therapy (26% vs. 28%, P = 0.8). Fifteen per cent (n = 14) of all patients failed to heal wounds at 6 months, but only 9 per cent (n = 2) of patients undergoing TT failed to heal their wounds at 6 months compared with 17 per cent (n = 12) in the non-TT group (P = 0.3). After controlling for important covariates, patients undergoing TT during an APR did not have a significantly lower rate of wound complications. The impact of TT on wound healing in patients with recurrent cancer and preoperative radiation therapy is suggestive of a benefit but requires prospective investigation.

Bone marker levels in gingival crevicular fluid during orthodontic intrusive tooth movement: a preliminary study.

The aim of the present study is to observe the changes in bone turnover markers, deoxypyridinoline (Dpd), osteocalcin, n-telopeptide (NTx), and bone alkaline phosphatase (balp) during the experimental orthodontic intrusion of maxillary premolar teeth. The study population required fixed appliance therapy involving the extraction of the maxillary first premolar teeth. Gingival crevicular fluid (GCF) samples were collected from each patient by using paper strips before the appliances were fitted and 1, 24, and 168 hours after the activation of appliances. After the second activation on the 21st, 22nd, and 28th days of the study, samples were collected. Enzyme-Linked Immunosorbent Assay (ELISA) tests were performed following manufacturer's recommendations. The results of the study indicate Dpd, osteocalcin, and balp values decrease with force application. Among the tested parameters only Dpd values showed statistically significant changes through time. One, 7, 22, and 28 day results show a significant amount of decrease when compared to 0 days. The extra decrease on the 22nd day (the day after the second activation) is also significantly lower. NTx crosslink values could not be detected in the experimental samples.

Significance of ligature technique on the formation of pulmonary artery stump thrombosis in a canine model.

BACKGROUND: Thrombo-embolism following pulmonary resection is a serious complication with a fatal outcome. We have tried to clarify the role of ligature techniques used in pulmonary resection on the formation of pulmonary artery stump thrombosis, which may lead to a subsequent pulmonary thrombo-embolism. MATERIAL AND METHODS: Two groups of 10 mongrel dogs underwent a standard left pneumonectomy under anesthesia. The transfixation, or the continuous ligature technique, was applied to close the pulmonary artery stump in each group. Morphological evaluation of the ligated pulmonary artery was carried out, including the macroscopic thrombus formation and microscopic findings. RESULTS: The transfixation ligature technique showed a significantly greater incidence of macroscopic thrombosis in the pulmonary artery stump when compared with the continuous ligature technique (p = 0.033). This was confirmed by microscopic changes (p = 0.020). CONCLUSION: Thrombus formation in the pulmonary artery stump is more likely to occur following the closure of the stump with the transfixation ligature technique compared with the continuous ligature technique.