OBJECTIVE. The relationship between metformin accumulation and lactate increase is still debated. This observational case series aims to evaluate the correlation of metformin plasma levels with the pH, lactate and creatinine levels, and with the mortality rate in selected patients with metformin accumulation confirmed through metformin plasma concentration detection at hospital admission. MATERIAL AND METHODS. All cases of lactic acidosis (pH, ≤ 7.35; arterial lactate, ≥ 5 mmol/L) related to metformin accumulation (plasma level ≥ 4 mcg/mL) from 2007 to 2011 were retrospectively reviewed. Erroneous ingestion and voluntary overdoses were excluded. Epidemiological, medical history, clinical and laboratory data were evaluated in all cases. RESULTS. Sixty-six patients were included. Thirty-one patients (47%) had contraindication to therapy with metformin. All patients showed severe lactic acidosis (pH, 6.91 ± 0.18; lactate, 14.36 ± 4.90 mmol/L) and acute renal failure (creatinine, 7.24 ± 3.29 mg/dL). The mean metformin plasma concentration was 40.68 ± 27.70 mcg/mL. Metformin plasma concentrations showed a correlation, statistically significant even if not strong, with creatinine (p = 0.002, R = 0.37), pH (p < 0.0001, R = - 0.43) and plasma lactate levels (p = 0.001, R = 0.41). Sixty-two (94%) underwent dialysis. Early mortality (before discharge from ICU) was 26% (17 cases). Lactate and metformin concentrations had mean levels not statistically different in surviving and deceased patients. CONCLUSIONS. Patients on chronic therapy with metformin may develop a mitochondrial-related toxicity that should be considered when patients present with lactic acidosis, renal failure, and frequently, a medical history of gastrointestinal manifestations during the days preceding the hospital admission. The correlation between metformin plasma concentrations and creatinine, pH, and lactate levels seems to be related to the mechanism of action (inhibition of complex I of the mitochondrial respiratory chain) and to the kinetic properties (high distribution volume and low protein binding) of the drug. The relevant early mortality seems not correlated with the levels of metformin or lactates: this could be due to the possible role of concurrent illness even if, such as for the relationships with lactate and creatinine, a more proper toxicological evaluation could be obtained by assessing metformin erythrocyte concentrations instead of the plasmatic ones.

Our aim was to compare two methods of treatment of ganglia on the volar aspect of the wrist (the open excision done through a longitudinal volar skin incision and the arthroscopic resection through two or three dorsal ports), to see if arthroscopy could reduce the risks of operating in this area and the time to healing. Twenty radiocarpal and five midcarpal volar ganglia were operated on by open approach and an equivalent group was treated by arthroscopy. Fifteen radiocarpal and five midcarpal ganglia were treated with good results in the open group and 18 radiocarpal and one midcarpal ganglia in the arthroscopic group (no visible or palpable ganglion, a full range of active wrist movement, grip strength equal to preoperatively, no pain, and a cosmetically acceptable scar). In the open group there were four injuries to a branch of the radial artery, two cases of partial stiffness of the wrist associated with a painful scar, one case of neuropraxia, and one recurrence (all of which were among the 20 radiocarpal ganglia). In the arthroscopic group there was one case of neuropraxia, one injury to a branch of the radial artery, and three recurrences (three of the complications were among the five midcarpal ganglia). The mean functional recovery time was equal to 15 (6) days in the open group and 6 (2) days in the arthroscopic group. The mean time lost from work was equal to 23 (11) days in the open group and 10 (5) days in the arthroscopic group. Our results suggest that arthroscopic resection is a reasonable alternative to open excision in treating radiocarpal volar ganglia because it has less postoperative morbidity and a better cosmetic result. Midcarpal volar ganglia, however, should still be treated by open operation.

The authors present the procedure and results of five years of arthroscopic treatment of wrist radiocarpal and midcarpal ganglia. Thirty cases of dorsal ganglia and seventeen cases of volar ganglia were operated on arthroscopically. The technique was easy to perform in all the radiocarpal ganglia, not easy in midcarpal dorsal ganglia and very difficult in midcarpal volar ganglia. The results were recorded with a mean follow-up of 15 months. Twenty-seven cases of dorsal ganglia and twelve cases of volar ganglia had excellent results with active motion recovery, no complications, absence of scars and no recurrence. Two cases had a recurrence. There were four complications: a case of injury of a radial artery branch, a case of extensive haematoma, and two cases of neuropraxia. In three cases the procedure was converted into open surgery: they had a longer time of healing and a residual scar. The arthroscopic resection has been in our experience effective and safe for the treatment of all radiocarpal ganglia. Good results have been obtained also in the treatment of dorsal midcarpal ganglia. Concerning the uncommon cases of volar midcarpal (STT) ganglia, an open approach seems still indicated.

The Cytomate device demonstrated a satisfying efficiency in cell recovery and in maintaining the clonogenic power of the UCB graft. The removal rate of DMSO was practically complete with evident advantages for the recipient. Finally, the entire manipulation performed in a closed system revealed to be safe, maintaining the sterility of the graft.