ORIGINAL ARTICLE Percutaneous kidney stone removal history, anatomy and statistical analysis of a group of patients J P van der Merwe BMedSc (Hons), MB ChB C S de Vries MMedRad(D) Department ot Diagnostic Radiology University ol the Free State Bloemfontein History Rupel and Brown removed the first kidney stone by surgical nephros- tomy tract in 1941. A percutaneous tract was developed by Ferntrëm and Johnson (1976) with the specific aim of removing the kidney stone via the mature tract. Inthe latter part of 1970, Smith and co-workers developed reli- able methods for percutaneous entrance to the pelvis and ureter, and started removing renal pelvic and ureter stones. Rathert and Aiken removed selective stones via a mature percutaneous tract during the same time.':' Anatomy It is necessary to understand the infundibular and calix anatomy, as well as the position and orientation of the kidney inside the body before a percutaneous kidney stone removal is performed. According to Kaye and Reinke,' Brëdel (1901) described the anatomy as follows: 'the posterior calyces point to a line just a little posterior to the lat- eral convex border of the kidney, while the anterior calyces are directed straight forward into the convex ante- rior region of the organ'. Brodel's illustrations indicate that the anterior calices project ± 700 from the coronal plane of the kidney, while the posterior calices are longer and are projected ± 200 posterior to the coro- nal plane (Fig. I). Hodson's model indicates that the posterior calices project to the mid posterior part of the kidney and the anterior calices are longer and are pro- jected just anterior to the convex later- al renal margin (Fig. I). On a standard excretory urogram the anterior row calices are usually viewed peripherally from the side as cup-like structures. The posterior rows are viewed more 24 SA JOURNAL OF RADIOLOGY • June 2002 HODSON anterior posterior Fig. 1. Models ol kidney anatomy. medially end-on as round concentra- tions of contrast medium (Fig. 2).3 Fig. 2, Position ol anterior and posterior calices (~ anterior calices, ~ posterior calices), In the case of a Brëdel type of kid- ney the posterior calices are viewed more laterally as cup-like structures, while the anterior calices are situated more medially and are viewed as round concentrations of contrast medium. ORIGINAL ARTICLE Kaye and Rienke' studied the renal anatomy of a number of patients using computerised tomography (CT) scans and concluded that the right kidney resembled mostly a Brëdel type and the left kidney resem- bled more a Hodson type. Statistical analysis The statistical analysis is for data collected during the period 1998 - 2001 in the Intervention Unit of the Diagnostic Radiology Department, University of the Free State. Eighty-five cases were treated. The patients' ages ranged from Il to 79 years (average 48 years), 58.5% were male and 41.5% were female. The per- centage of patients treated per year is as follows: 18.8% in 1998, 16.5% in 1999, 25.9% in 2000 and 38.8% in 2001. Kidney stones were present in one kidney in 97.6% of the patients and bilaterally in 2.4% of the patients. One kidney stone was present in 68.3% of the patients and more than one kid- ney stone in 31.7% of the patients. The kidney stones were situated in the posterior calix system in all patients except one, where it was situ- ated in the anterior calix system. The position of the kidney stones in the posterior calix system was as follows: 8.8% in the top section, 8.8% in the mid section and 42.5% in the lower section. The kidney stones of only one patient were present intraparenchy- mally. Kidney stones were situated in the pelvis in 35% of the cases and in the ureter in 15% of the cases. More than half (58.8%) of the stones were successfully removed, 23.4% were removed incompletely in a single treatment, and 18.8% of the stones could not be removed. Incomplete stone removal was as a result of intraoperative bleeding, extravasation, multiple stones which could not be reached with a single tract, transference of stones to unreachable calices and small residual fragments smaller than 3 mm. Wong' reported a success rate of 97% after the following technique refinements: (1) single stadium percu- taneous nephrostomy in theatre; (ii) use of a flexible endoscope to judge the entire pelvic-calix system; and (iit) liberal use of secondary percutaneous kidney stone removal to ensure a stone- free status. Conclusions Percutaneous kidney stone removal is conducted with a high suc- cess rate, minimal morbidity and is the procedure of choice for kidney stone removal in most patients as well as children." References 1. Ramakumar S, Segura TW.Renal calculi percu- taneous management. Ural Clin North Am 2000; 27: 617-622. 2. . Segura TW. Endourology. JUra! 1984; 132: 1079-1084. 3. Kaye KW, Reinke DB. Detailed caliceal anatomy for endourology. J Ural 1984; 132: 1085-1088. 4. Wong MY. Evolving technique of percutaneous nephrolithotomy in a developing country: Singapore General Hospital Experience. J Endouro!1998; 12: 397-401. 5. Badaway H, Salama A, Eissa M, Kotb E, Moro H, Shoukiri I. Percutaneous management of renal calculi: experience with percutaneous nephrolithotomy in 60 children. JUral 1999; 162: 1710- J 713. 6. Maheshwarz PN, Andondken M, Hegde S, Bansal M. Bilateral single session percutane nephrolithotomy: a feasible and safe treatment. JEndourol2000; 14: 285-287. 25 SA JOURNAL OF RADIOLOGY • June 2002