Which type of procedure is most effective and safe for patients with kidney stones?

This study compared two types of percutaneous nephrolithotomy (PCNL) procedure to treat patients with kidney stones. The results showed that miniaturized PCNL (mPCNL) was slightly more effective and as safe as standard PCNL (sPCNL).

Percutaneous nephrolithotomy (PCNL) is a procedure to treat patients with kidney stones. It involves a small cut into the back through which a tube with a camera is inserted into the kidney. It is used to remove the stone(s) that cannot be passed through the urinary system. PCNL is one of the best treatment options for patients with kidney stones that are larger than 2 cm. However, some patients suffer significant blood loss and pain during the standard procedure. 

Miniaturized PCNL (mPCNL) uses a smaller tube to prevent these side effects. It is unclear if mPCNL is as effective as standard PCNL (sPCNL).

The results of 9 studies comparing mPCNL to sPCNL were compared. 1219 patients with kidney stones received either mPCNL or sPCNL.

Patients who underwent mPCNL were 43% more likely to have no kidney stones after the procedure than those who underwent sPCNL. Patients who underwent mPCNL were 67% less likely to need a blood transfusion than sPCNL. Drops in red blood cell levels were significantly lower in the mPCNL group, indicating less blood loss.

There were significant differences between the groups in terms of the number of patients who developed a fever, had breathing problems, urine leakage, or the number who experienced complications. The time spent in the operation was longer in the mPCNL group than the sPCNL. There was no significant difference between the groups for the time spent overall in the hospital.

For kidney stones larger than 2 cm, mPCNL was associate with increased operation time. However, is was also associated with a 58% lower number of blood transfusions and a lower drop in red blood cell levels. The type of PCNL made no difference to patients with stones larger than 2 cm with respect to the number of patients with no stones left, the length of stay in the hospital, development of fever, breathing problems, or the development of complications.

Whether patients got sPCNL or mPCNL made no difference based on the location of the kidney stones.  The only significant difference is that patients with stones in the calyx part of the kidney had a longer operation time with mPCNL than sPCNL by 13.18 minutes. 

The authors concluded that mPCNL was slightly more effective than sPCNL, although the operation time was longer.

The studies used in this research used a small number of patients. There were significant differences between the setup of studies, meaning that not all results are comparable. Some information was missing in some studies, such as the location of the kidney stones.