Clinical and Variant Anatomy of the Blood Supply to the Body and Tail of the Human Pancreas

The aim of the study was to specify peculiarities of the blood supply to the body and tail of the human pancreas determining topographic variants and vascular bed of the splenic artery.Material and methods. The artery basin of the pancreas body and tail was studied in 46 native and 42 organ complexes consisting of the pancreas, duodenum, spleen, retropancreatic tissue, celiac trunk with the main branches, a section of the superior mesenteric artery up to the entrance into the root of the small intestine mesentery with the preliminary artery injection by gelatin mass. The organ complexes were fixed in 10% formalin solution.Results. The study revealed two variants of the splenic artery topography in relation to the pancreas and determined the degree of tortuosity of the artery. In 31.7% of cases the vessel passed retro-pancreatically and in 68.3% suprapancreatically. Moderate tortuosity of the splenic artery was detected most frequently (44.82%); in 34.48% of cases severe tortuosity was detected; in 17.24% of cases there was no tortuosity in the artery. The correlation between area/convolution and the number of pancreatic arteries was found to be 0.864 (p=0.05), which is considered to be a high parameter according to the Cheddock scale. In severe tortuosity of the splenic artery 3.16±0.37 pancreatic arteries on average closed to the corpus caudal segment of the pancreas, in moderate tortuosity – 5.09±1.24, in straight passage – 9±1.22.Conclusion. The regularities revealed in the spleen artery topography, blood supply of the pancreas body and tail allow determining operational risks and tactics of surgical interventions on the corpus caudal segment of the pancreas.

The Effect of Extended SMAS Face-lift on Earlobe Ptosis and Pseudoptosis

In this study, we explore the changes in the earlobe segments following an extended superficial musculoaponeurotic system (SMAS) face-lift and neck lift. We proposed to delineate the effect of the cheek and neck skin tension vectors on the earlobe based on the amount of excised skin length. A retrospective study identified patients who underwent extended SMAS rhytidectomy performed by the senior author (A.M.) at the Cosmetic Plastic Surgery Institute (CPSI) from 2017 to 2020. A total of 34 North American Caucasians, who had preoperative and postoperative photographs available for comparison, were evaluated. Preoperative and postoperative cephalic (the distance from the intertragal notch to the otobasion inferius, abbreviated as I to O) and caudal earlobe segment (the distance from the otobasion inferius to the subaurale, abbreviated as O to S) heights were collected. The change from the postoperative to preoperative measurements was calculated. The effects of the degree of cheek skin (superior ear [SE]) and neck skin (mastoid peak [MP]) excision lengths were then determined by comparing the change in I to O and O to S. The postoperative attached cephalic segment (15.94 ± 1.02 mm) increased significantly compared with the preoperative attached cephalic segment (12.99 ± 1.03 mm). The postoperative free caudal segment (3.62 ± 0.81 mm) decreased significantly compared with the preoperative free caudal segment (5.44 ± 0.95 mm). The SE median was found to be 3.0 cm and the MP median was found to be 3.5 cm. I to O increased by 3.85 mm for SE ≤3.0 cm compared with only 1.57 mm for SE >3.0 cm. O to S decreased by 2.79 mm for SE ≤3.0 cm compared with only decrease of 0.14 mm for SE >3.0 cm. I to O increased by only 1.67 mm for MP < 3.5 cm. O to S decreased less dramatically by 0.55 mm for MP ≤3.5 cm compared with decrease of 2.39 mm for MP >3.5 cm. These data demonstrate that more aggressive SE >3.0 cm cheek excision lengths resulted in a protective effect on decreasing the free caudal segment of the earlobe. More aggressive excisions of the cheek demonstrate a protective effect on preserving the free earlobe caudal segment, whereas more aggressive neck skin excisions result in higher propensity for loss of the free earlobe caudal segment. In our study, we demonstrate findings observed with clinical observations that a face-lift and neck lift will result in increase in the attached cephalic earlobe segment height (I to O) and a decrease in caudal free earlobe segment height (O to S). These findings may assist plastic surgeons when trying to fine-tune the earlobe aesthetics during face-lift and neck lift. If the patient has a small free hanging earlobe, the more aggressive pull on the cheek flap will result in less reduction in the earlobe hang.

Anatomical, Histological and Histochemical Features of the Guinea Pig (Cavia porcellus) Caecum

In this study, the caecum of five guinea pigs was anatomically, histologically, and histochemically analyzed. From an anatomical point of view, it has been proved that the caecum in guinea pigs occupies the caudal segment of the abdominal cavity and consists of three parts: the ampullary portion, the body of the caecum, and the apex of the caecum, without a caecal appendix. In our histological analysis, we observed that the caecum has a simple structure, and the cecal mucosal glands are rare and contain, in addition to enterocytes, a small number of goblet cells, which are better represented in the deep part of the glands. Histochemically it has been observed that goblet cells are PAS and Alcian blue positive, which shows that they secrete both neutral and acidic mucins. The intensity of these two histochemical reactions is similar to that of goblet cells from other intestinal segments, proving that they are typical goblet cells. The large volume of the caecum suggests that this is an important section for the digestion process, although the relatively simple structure of the caecal mucosa suggests that the digestion here is not preponderant, but only complements the intestinal one.

Adjacent-segment disease after L3–4 posterior lumbar interbody fusion: does L3–4 fusion have cranial adjacent-segment degeneration similar to that after L4–5 fusion?

OBJECTIVEPosterior lumbar interbody fusion (PLIF) is a widely accepted procedure for degenerative lumbar diseases, and there have been many reports concerning adjacent-segment disease (ASD) after PLIF. In the reports of ASD in which the fusion level was limited to 1 segment, all reports describe ASD of the L3–4 segment after L4–5 PLIF. On the basis of these reports, it is thought that ASD mainly occurs at the cranial segment. However, no report has covered ASD after L3–4 PLIF. Therefore, the authors investigated ASD after L3–4 PLIF.METHODSIn conducting a retrospective case series analysis, the authors reviewed a surgical database providing details of all spine operations performed between 2006 and 2017 at a single institution. During that period, PLIF was performed to treat 632 consecutive patients with degenerative lumbar diseases. Of these patients, 71 were treated with L3–4 PLIF alone, and 67 who were monitored for at least 2 years (mean 5.8 years; follow-up rate 94%) after surgery were enrolled in this study. Radiological ASD (R-ASD), symptomatic ASD (S-ASD), and operative ASD (O-ASD) were evaluated. These types of ASD were defined as follows: R-ASD refers to radiological degeneration adjacent to the fusion segment as shown on plain radiographs; S-ASD is a symptomatic condition due to neurological deterioration at the adjacent-segment degeneration; and O-ASD refers to S-ASD requiring revision surgery.RESULTSAll patients had initial improvement of neurological symptoms after primary PLIF. R-ASD was observed in 32 (48%) of 67 patients. It occurred at the cranial segment in 12 patients and at the caudal segment in 24; R-ASD at both adjacent segments was observed in 4 patients. Thus, the occurrence of R-ASD was more significant in the caudal segment than in the cranial segment. S-ASD was observed in 10 patients (15%), occurring at the cranial segment in 3 patients and at the caudal segment in 7. O-ASD was observed in 6 patients (9%): at the cranial segment in 1 patient and at the caudal segment in 5. Thus, the rate of involvement of the caudal segment was 67% in R-ASD, 70% in S-ASD, and 83% in O-ASD.CONCLUSIONSThe incidences of R-ASD, S-ASD, and O-ASD were 48%, 15%, and 9%, respectively, after L3–4 PLIF for degenerative lumbar diseases. In contrast to ASD after L4–5 PLIF, ASD after L3–4 PLIF was more frequently observed at the caudal segment than at the cranial segment. In follow-up for patients with L3–4 PLIF, surgeons should pay attention to ASD in the caudal segment.

Low-grade spondylolisthesis: is transforaminal lumbar interbody fusion superior to posterolateral fusion

<p class="abstract"><strong>Background:</strong> Spondylolisthesis is anterior translation of the cephalad vertebra relative to the adjacent caudal segment. Both posterolateral fusion (PLF) and transforaminal lumbar interbody fusion (TLIF) and have shown high fusion rates with good clinical outcomes. But it is not clear which treatment leads to better outcomes, as limited studies have been done to compare PLF and TLIF in low grade spondylolisthesis. Our objective is to determine whether PLF or TLIF was associated with better clinical and radiological outcomes in patients with low grade spondylolisthesis.</p><p class="abstract"><strong>Methods:</strong> Fourty patients were enrolled and assigned into PLF (n=20) or TLIF (n=20) group. The outcome measures were: clinical outcomes as assessed with a visual analogue scale and the modified Oswestry disability index, the fusion rate based on radiographs.<strong></strong></p><p class="abstract"><strong>Results:</strong> The improvement of visual analog score (VAS) of low back pain was greater in TLIF than in PLF (89.6% versus 88.7%, p=0.79). The improvement of VAS of leg pain was greater in TLIF than in PLF (96.5% versus 94.8%; p=0.27). The improvement of Oswestry disability index (ODI) was greater in TLIF than in PLF (71.7% vs 69.8%, p=0.32). The fusion rate was 85% in TLIF and 75% in PLF (p=0.43). Overall outcome was excellent in 80% in TLIF compared to 65% in PLF (p=0.29).</p><p class="abstract"><strong>Conclusions:</strong> Fusion rates are higher in TLIF and average functional outcomes (VAS and ODI) were better in TLIF compared to PLF. Larger and longer studies may provide a significant outcome. Based on our results and literature review, we conclude that TLIF is superior to PLF.</p>

Palatal Sphincter Pharyngoplasty With Cephalic Mucosa Preservation in Selected Cases of Velopharyngeal Insufficiency

Objectives: Sphincter pharyngoplasty is a commonly performed procedure for the treatment of velopharyngeal insufficiency and is often indicated in patients with circular or coronal closure patterns of the velopharyngeal sphincter. The authors present a modified technique of sphincter pharyngoplasty (partially mucosalized palatal sphincter pharyngoplasty [PMPSP]) in which bilateral superiorly based myomucosal palatopharyngeal flaps were elevated (in a newly designed fashion) and inserted in the palate through preformed palatal tunnels. Methods: This case series included 14 patients (5 male, 9 female) with persistent hypernasality who were subjected to treatment by PMPSP between May 2015 and August 2018. The palatopharyngeal flap was designed to be full thickness at its caudal segment, while its cephalic segment was denuded of its mucosa. The cephalic mucosa (of the flap) was elevated off the bed muscles as a medially based mucosa flap to be used at the end of the procedure to drape the upper part of the bed. Results: Pain assessed using a visual analog scale had decreased significantly at day 10 after surgery, and normal oral feeding was regained within 7 to 10 days. No major complications were recorded. Postoperative nasoendoscopic and phoniatric assessments were reported. Statistically significant improvements were reported when comparing pre- versus postoperative auditory perceptual assessment following PMPSP. Conclusions: The newly reported PMPSP might be a useful technique for correction of velopharyngeal insufficiency in patients with weak palatal motion (coronal or circular pattern of velopharyngeal sphincter closure). PMPSP had good reported surgical and phoniatric outcomes.

Landlubbers to leviathans: evolution of swimming in mosasaurine mosasaurs

Incremental stages of major evolutionary transitions within a single animal lineage are rarely observed in the fossil record. However, the extraordinarily complete sequence of well preserved material spanning the 27-Myr existence of the marine squamate subfamily Mosasaurinae provides a unique exception. By comparison with extant and extinct analogs, the tail morphology of four mosasaurine genera is examined, revealing a pattern of evolution that begins with the generalized varanoid anatomy and culminates in a high-aspect-ratio fin, similar to that of sharks. However, unlike the epicercal caudal fluke of selachians in which the tail bends dorsocaudally, derived mosasaurs develop a hypocercal tail with a ventrocaudal bend. Progressive caudal regionalization, reduced intervertebral mobility, increased tail depth due to a marked downturn of the posterior caudal segment, and the development of finlike paired appendages reveal a pattern of adaptation toward an optimized marine existence. This change in morphology reflects a transition from anguilliform or sub-carangiform locomotion to carangiform locomotion, and indicates a progressive shift from nearshore dwellers to pelagic cruisers—a change in foraging habitat independently corroborated by paleobiogeographic, stable isotope, osteohistological, and paleopathological data. Evolutionary patterns similar to those observed in mosasaurine mosasaurs are seen in other secondarily aquatically adapted amniotes, notably metriorhynchid crocodyliforms, cetaceans, and ichthyosaurs, and may be explained by developmental modularity governing the observed phenotypic expression.

fMRI-Adaptation Reveals Dissociable Neural Representations of Identity and Expression in Face Perception

The distributed model of face processing proposes an anatomical dissociation between brain regions that encode invariant aspects of faces, such as identity, and those that encode changeable aspects of faces, such as expression. We tested for a neuroanatomical dissociation for identity and expression in face perception using a functional MRI (fMRI) adaptation paradigm. Repeating identity across face pairs led to reduced fMRI signal in fusiform cortex and posterior superior temporal sulcus (STS), whereas repeating emotional expression across pairs led to reduced signal in a more anterior region of STS. These results provide neuroanatomical evidence for the distributed model of face processing and highlight a dissociation within right STS between a caudal segment coding identity and a more rostral region coding emotional expression.