Laparoscopic grasper for intramedullary biopsy: a technique to improve tissue sampling

Reaming samples are usually sent for histological testing to establish or confirm the primary source of malignancy while intramedullary nailing is performed for impending or established pathological fracture of the long bones. However, this conventional technique of sampling does not always yield accurate results. Herein, we introduce a technique for intramedullary biopsy using a laparoscopic grasper under image intensifier guidance. This novel technique was applied in three cases, and the tissue samples obtained successfully established or confirmed the primary source of malignancy. In comparison, reaming samples obtained via the conventional method showed negative findings in one case and tumour cells that were of poor sample quality in another case. We opine that this new technique is an effective and reproducible method that could improve tissue sampling and achieve a more reliable histological diagnosis.     

Pharmacokinetics of cysteamine bitartrate following intraduodenal delivery

Cysteamine is approved for the treatment of cystinosis and is being evaluated for Huntington's disease and non‐alcoholic fatty liver disease. Little is known about the bioavailability and biodistribution of the drug. The aim was to determine plasma, cerebrospinal fluid (CSF), and tissue (liver, kidney, muscle) cysteamine levels following intraduodenal delivery of the drug in rats pretreated and naïve to cysteamine and to estimate the hepatic first‐pass effect on cysteamine. Healthy male rats (n = 66) underwent intraduodenal and portal (PV) or jugular (JVC) venous catheterization. Half were pretreated with cysteamine, and half were naïve. Following intraduodenal cysteamine (20 mg/kg), serial blood samples were collected from the PV or the JVC. Animals were sacrificed at specific time points, and CSF and tissue were collected. Cysteamine levels were determined in plasma, CSF, and tissue. The C_max was achieved in 5–10 min from PV and 5–22.5 min from JVC. The PV‐C_max (P = 0.08), PV‐AUC_0–t (P = 0.16), JVC‐C_max (P = 0.02) and JVC‐AUC_0–t (P = 0.03) were higher in naive than in pretreated animals. Plasma cysteamine levels returned to baseline in ≤120 min. The hepatic first‐pass effect was estimated at 40%. Peak tissue and CSF cysteamine levels occurred ≤22.5 min, but returned to baseline levels ≤180 min. There was no difference in CSF and tissue cysteamine levels between naïve and pretreated groups, although cysteamine was more rapidly cleared in the pretreated group. Cysteamine is rapidly absorbed from the small intestine, undergoes significant hepatic first‐pass metabolism, crosses the blood brain barrier, and is almost undetectable in plasma, CSF, and body tissues 2 h after ingestion. Sustained‐release cysteamine may provide prolonged tissue exposure.     

An unusual clinical presentation of myxoid dermatofibrosarcoma protuberans with a prominent vasculature: A potential pitfall in the diagnosis of myxoid soft tissue tumors

Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue tumor that arises primarily on the trunk and extremities but seldom on the scalp. Several variants of DFSP have been described, including myxoid DFSP. Although typical DFSP may have focally myxoid areas, myxoid DFSP, in which most of the stroma is myxoid, is rare and can pose diagnostic challenges. Here, we report a case of myxoid DFSP with an unusual clinical presentation that could have been mistaken for a lipoma. Additionally, the myxoid DFSP displayed prominent vasculature in a myxoid stroma, which could have been mistaken for a myxoid liposarcoma.     

Appendixes 1–8

Preclotting is an essential procedure for porous fabric vascular prostheses, but fatal bleeding due to fibrinolysis after implantation can occur in some cases. To overcome this problem, a method was developed to seal highly porous fabric vascular prostheses with adipose connective tissue fragments. A piece of subcutaneous adipose connective tissue weighing approximately 1 g was minced with scissors and stirred into 20 mL of saline, thereby creating a tissue suspension. This was sieved through the wall of a highly porous fabric prosthesis from the outside to the inside by intraluminal suction. The prostheses were implanted in the thoracic descending aortae of 20 dogs and removed from 1 h to 1 year after implantation. Twelve preclotted prostheses were used as controls. None of the treated grafts experienced bleeding complications postoperatively. In the controls, the chest wall was closed after the bleeding stopped from the suture line and through the prosthesis wall, but problems occurred after surgery. Three out of 12 control animals (25%) bled in the pleural cavity within 24 h. In the tissue-sealed grafts, smooth neointima formation without any degenerative changes was observed during a 1-year observation period.